Quantitative Study of Fingering Pattern Created by Smoldering Combustion

Size: px
Start display at page:

Download "Quantitative Study of Fingering Pattern Created by Smoldering Combustion"

Transcription

1 Quantitative Study of Fingering Pattern Created by Smoldering Combustion Tada Y. 1, Suzuki K. 1, Iizuka H. 1, Kuwana K. 1, *, Kushida G. 1 Yamagata University, Department of Chemistry and Chemical Engineering, Yonezawa, Yamagata, Japan Aichi Institute of Technology, Department of Mechanical Engineering, Toyota, Aichi, Japan *Corresponding author kuwana@yz.yamagata-u.ac.jp ABSTRACT Smoldering combustion occurs when a solid is burned in a narrow channel. A fingering pattern is then formed owing to the instability of smoldering front. We recently extended the stability analysis by Kagan and Sivashinsky to include a heat loss term and identified an ective Lewis number as the governing parameter of fingering instability. The ective Lewis number unifies the influences of material properties, experimental configuration, heat loss, and forced oxidizer flow. This study presents experimental and numerical results to further validate the stability analysis, especially, the definition of the ective Lewis number. Thin paper sheets of two different materials are burned in a narrow gap under a forced oxidizer flow. The fraction burned and the average finger width are determined by image analysis and plotted as functions of the ective Lewis number. Numerical simulations without considering heat loss or convection term are also conducted, and their results are compared with the experimental data. KEYWORDS: Fingering instability, image analysis, Lewis number, smoldering combustion. NOMENCLATURE c specific heat (J/(kg K)) D diffusivity (m /s) d channel height (m) g d s solid thickness (m) h heat transfer coicient (W/(m K)) Lewis number (-) Le ective Lewis number (-) Nu D Nusselt number (-) Q heat of combustion (J/kg) T temperature (K) t time (s) U scaled oxidizer velocity (-) u oxidizer velocity (m/s) u r reference velocity (m/s) W rate of surface reaction (kg/(m s)) Y O oxygen mass fraction (-) Greek scaled Lewis number (-) Zel dovich number (-) scaled heat transfer coicient (-) thermal conductivity (W/(m K)) density (kg/m 3 ) Subscripts g gas phase s solid phase u unburned INTRODUCTION Smoldering spread along a combustible solid often occurs at an early stage of fire. Smoldering combustion is also common in wildland fires such as those causing haze problems in Southeast Proceedings of the Eighth International Seminar on Fire and Explosion Hazards (ISFEH8), pp Edited by Chao J., Liu N. A., Molkov V., Sunderland P., Tamanini F. and Torero J. Published by USTC Press ISBN: DOI:10.085/c.sklfs.8thISFEH.006 5

2 Part II Fire Asia and Northeast Europe [1]. This paper focuses on smoldering spread along a thin solid in a narrow channel, which is known to show interesting fingering instability [-4] (see also Ref. [5]). In a typical narrow channel experiment [3-6], a thin solid such as a filter paper is burned in a narrow gap between two parallel plates. A forced oxidizer flow in the opposite direction to the smoldering spread is usually supplied to avoid extinction. Previous experimental studies [3-6] showed that channel height, oxidizer velocity, and oxygen concentration in the oxidizer stream as well as material properties are key experimental parameters influencing fingering instability (see Fig. 1 for a typical experimental configuration). Among them, channel height controls the heat loss to the parallel plates as the heat transfer coicient depends on it as g Figure 1. Experimental setup. NuDλ g h =. (1) d Kagan and Sivashinsky [7] conducted a stability analysis of the fingering instability and derived a nonlinear equation for smoldering front. They numerically solved the equation and successfully reproduced a fingering pattern consisting of repetitive splits and merging. Their model, however, did not consider heat loss ect, making quantitative comparison between model predictions and experimental results difficult. We recently extended the Kagan-Sivashinsky model to include a heat loss term [8]. The dispersion relation obtained by the extended model has a single parameter, an ective Lewis number. The ective Lewis number unifies the ects of material properties, heat loss, and oxidizer flow. The results of experiments under different series of conditions supported the definition of the ective Lewis number as the governing parameter. This paper presents the results of experiments using a different paper material and newly conducted numerical simulations to further validate the theory. EFFECTIVE LEWIS NUMBER Kuwana et al. [8] based their analysis on the following -D basic equations: T t T x ( ρ gcgd g + ρ scd s s ) + ρ gcgd gu = ( λ gd g + λ gd g ) T + QW h( T Tu ) ρ YO YO gd g gd gu gd gd YO W t ρ + = x ρ, (), (3) which are obtained by the same reduction technique as Kagan and Sivashinsky [7]. Here, is the longitudinal direction, while is the transverse direction. The last term on the right hand side of Eq. () expresses the ect of heat loss. A first-order reaction of oxygen is assumed for, whereas the 53

3 Proceedings of the Eighth International Seminar on Fire and Explosion Hazards (ISFEH8) pyrolysis reaction is not considered (see Ref. [9] for the ects of pyrolysis reaction). Linear stability analysis to system and 3 leads to the following dispersion relation: 4 1 k 4k ω = α + InU + 1 k, U U where the scaled Lewis number, the scaled heat transfer coicient k, and the scaled oxidizer velocity are defined by the following equations: Le = 1 α k u, h, U, β = β = (5) u r where is the Zelʼdovich number, is the Lewis number defined as = + / ( ), and h is the dimensionless heat transfer coicient defined as h = h + / ( ). The reference velocity is defined as the oxidizer velocity at which smoldering spread velocity becomes zero [7-9]. Note that the wavelength is scaled by + /( ) in the present dimensionless system. With the transformation of = and =, Eq. (4) simplifies to 1 4 ˆ k ω = α InU 1 kˆ 4 kˆ + +. U (6) On the other hand, Uchida et al. [6] and Kuwana et al. [10] considered the following simple model without oxidizer flow or heat loss: (4) T T + t W, (7) Y O t 1 = YO Le W, (8) where is the ective Lewis number, and overbar denotes the dimensionless variable used in Ref. [6]. It was demonstrated that these simple equations can reproduce fingering patterns with repetitive splits and local extinction of fingertip when the ective Lewis number is sufficiently small. Linear stability analysis to system 7 and 8 yields ( α ) ω = (9) 4 1 k 4 k, where = (1 )/. Comparing Eq. (9) with (6), one can define the ective Lewis number as = +ln + / or 1 k Le Le In = U + β U Eq. (10) defines the ective Lewis number that unifies the influences of material properties, heat loss, and oxidizer flow. Eq. (6) yields the critical wavelength at which is maximal as (10) 3π l ˆ max( = Ulmax ) = β 1 1, ( Le ) (11) 54

4 Part II Fire which is to be compared with experimentally measured and numerically predicted finger widths. EXPERIMENTAL METHOD Narrow channel experiments similar to [3-6, 8] were conducted. Fig. 1 shows a schematic diagram of the present experiment. A thin paper sheet of 80 mm wide 300 mm long was burned in a narrow channel between two parallel plates. The same filter paper and low density paper as [6] were used, and their thermophysical properties were listed there. The vertical location of the paper sheet was at the center of the channel. A plate of heat-resistant glass was used as the top plate to enable visual observation from the top. An oxidizer flow of a specified velocity was supplied in the opposite direction to the smoldering spread. The paper edge on the downstream side of oxidizer flow was uniformly ignited using a slot burner. The following three experimental parameters were varied: the channel height,, from 7 to 1 mm; the oxidizer velocity,, from 15 to 35 mm/s; and the oxygen mass fraction in the oxidizer stream from 0.3 to Typical fingering patterns obtained are shown in Fig.. Both finger width and fraction burned increase with an increase in channel height or oxidizer velocity. Image analysis was conducted to quantify obtained fingering patterns. An area of 80 mm 170 mm, where quasi-steady spread was achieved, was used for the image analysis. For each image, the fraction burned and the average finger width were obtained. Ten runs were conducted under each condition, and the average value over the ten runs is reported below. = 7 mm = 11 mm (a) = 5 mm/s,, = 0.3 = 15 mm/s = 30 mm/s (b) = 10 mm,, = 0.3 Figure. Experimentally obtained fingering patterns. NUMERICAL METHOD Eqs. (7) and (8) were numerically solved under varied values of. The (dimensionless) size of computational domain is The purpose of the present numerical simulation is to compare its results with Eq. (6), obtained from more complicated Eqs. () and (3). This way, the idea of ective Lewis number introduced in this study can be tested. An explicit finite difference method was used to solve Eqs. (7) and (8). A periodic boundary condition was applied in the transverse direction. As boundary conditions on the burned and the unburned sides, zero second-derivative conditions were adopted. An initial perturbation of a sine curve was imposed, and the evolution of fingering pattern was computed. 55

5 Proceedings of the Eighth International Seminar on Fire and Explosion Hazards (ISFEH8) The size of computational cell was fixed at 0.05 in both transverse and longitudinal directions, and the time step was fixed at It was confirmed that a test run with the cell size of 0.0 yielded a nearly identical result to that with the cell size of RESULTS AND DISCUSSION Fig. 3 shows numerical results for = 0.15 and 0.4. A fingering pattern is the trace of smoldering front that has a reaction rate greater than a certain threshold value. Therefore, a fingering pattern can be numerically obtained from the distribution of the maximal reaction rate during the simulated period of time. Fingering patterns shown in Fig. 3 are thus obtained. Comparison between Fig. 3(a) and (b) shows that both finger width and fraction burned increase with an increase in. Numerically predicted fingering patterns were processed in a similar way to that described in the previous section to obtain finger width and fraction burned as functions of Temperature 0 1 Oxygen mass fraction Fingering pattern (a) Le = 0.15, t = 6 Figure 3. Numerical results. 56

6 Part II Fire Temperature 0 1 Oxygen mass fraction Fingering pattern (b) Le = 0.4, t = 6 Figure 3. (Continued) Fig. 4 plots experimentally measured and numerically predicted finger width as functions of the ective Lewis number,, defined by Eq. (10). The material properties and parameter values used to evaluate are listed in Ref. [8]. Eq. (11) is also shown in the same figure. As mentioned in [8], the choice of material properties changes the value of, but the conclusions of this study remain unchanged. In the experiment, as described above, finger width increases with an increase in channel height or oxidizer velocity. In the numerical simulation, on the other hand, finger width increases with. When experimental data are plotted as a function of, they are close to the numerical results, confirming that defined by Eq. (10) can unify the influences of heat loss (channel height) and oxidizer velocity. The values of under several conditions are negative, which is physically impossible. These are conditions under which the accuracy of the stability analysis is limited. Nevertheless, negative value causes no trouble in calculating finger width using Eq. (11), which agrees reasonably well with the experimental and numerical results. Experimental data under various oxygen concentrations are also plotted in Fig. 4. Under these conditions, is much less than zero, 57

7 Proceedings of the Eighth International Seminar on Fire and Explosion Hazards (ISFEH8) and finger width is insensitive to. More experimental data are needed to further assess the ect of oxygen concentration. Eq. (11) tends to overestimate the finger width when is less than about 0.5. A reason for the error is that the analytical model (Eq. (11)) does not consider local extinction, while both the numerical (Fig. 3) and experimental (Fig. ) results show local extinction. Fig. 5 plots experimentally measured and numerically predicted fraction burned as functions of the ective Lewis number. Unlike finger width, the fraction burned is strongly influenced by the initial disturbance, and therefore experimental error tends to be large. Overall, the fraction burned increases with an increase in. The experimental data are close to numerical results, validating the use of to combine the influences of experimental parameters. The present stability analysis considers small perturbation from the steady unperturbed spread. Therefore, the theory cannot predict local extinction and hence fraction burned. A different theoretical consideration is necessary to predict fraction burned. U (finger width) Eq. (11) Le Figure 4. Finger width and ective Lewis number. varied, = 5 mm/s,, = 0.3 (filter paper); = 10 mm, varied,, = 0.3 (filter paper); = 7 mm, = 5 mm/s,, varied (filter paper); varied, = 5 mm/s,, = 0.3 (low density paper); Numerical simulation Fraction burned Le Figure 5. Fraction burned and ective Lewis number. The same symbols as Fig. 4 are used. CONCLUSIONS Narrow-gap experiments using a different paper material and numerical simulations were newly conducted to validate the prediction of previously-conducted linear stability analysis, in particular, 58

8 Part II Fire the definition of ective Lewis number that combines the influences of heat loss and oxidizer flow as well as material properties. The numerical model does not include convection or heat loss term, while in the experiment, oxidizer flow was supplied and heat loss to the bottom and top plates existed. Experimentally measured finger width and fraction burned were plotted as functions of the ective Lewis number, and the experimental data were in line with numerical predictions, validating its definition. ACKNOWLEDGMENTS This work was supported by JSPS KAKENHI Grant Numbers and 15H0977. REFERENCES 1. Huang, X., and Rein, G. Smouldering Combustion of Peat in Wildfires: Inverse Modelling of the Drying and the Thermal and Oxidative Decomposition Kinetics, Combustion and Flame, 161(6): , Olson, S. L., Baum, H. R., and Kashiwagi, T. Finger-Like Smoldering over Thin Cellulosic Sheets in Microgravity, Proceedings of the Combustion Institute, 7(): , Zik, O., and Moses, E. Fingering Instability in Solid Fuel Combustion: The Characteristic Scales of the Developed State, Proceedings of the Combustion Institute, 7(): , Zik, O., and Moses, E. Fingering Instability in Combustion: An Extended View, Physical Review E, 60(1): , Olson, S. L., Miller, F. J., Jahangirian, S., and Wichman, I. S. Flame Spread Over Thin Fuels in Actual and Simulated Microgravity Conditions, Combustion and Flame, 156(6): , Uchida, Y., Kuwana, K., and Kushida, G. Experimental Validation of Lewis Number and Convection Effects on the Smoldering Combustion of a Thin Solid in a Narrow Space, Combustion and Flame, 16(5): , Kagan, L., and Sivashinsky, G. Pattern Formation in Flame Spread over Thin Solid Fuels, Combustion Theory and Modelling, 1(): 69-81, Kuwana, K., Suzuki, K., Tada, Y., and Kushida, G. Effective Lewis Number of Smoldering Spread over a Thin Solid in a Narrow Channel, Proceedings of the Combustion Institute, 36(): , Lozinski, D., and Buckmaster, J. Quenching of Reverse Smolder, Combustion and Flame, 10(1): , Kuwana, K., Kushida, G., and Uchida, Y. Lewis Number Effect on Smoldering Combustion of a Thin Solid, Combustion Science and Technology, 186(4-5): ,

Study on Train Obstruction Effect on Smoke Control near Tunnel Cross-Passage

Study on Train Obstruction Effect on Smoke Control near Tunnel Cross-Passage Study on Train Obstruction Effect on Smoke Control near Tunnel Cross-Passage Hou Y. S., Li Y. F.*, Li J. M. Beijing University of Technology, College of Architecture and Civil Engineering, Beijing, China

More information

S. Kadowaki, S.H. Kim AND H. Pitsch. 1. Motivation and objectives

S. Kadowaki, S.H. Kim AND H. Pitsch. 1. Motivation and objectives Center for Turbulence Research Annual Research Briefs 2005 325 The dynamics of premixed flames propagating in non-uniform velocity fields: Assessment of the significance of intrinsic instabilities in turbulent

More information

GLOWING AND FLAMING AUTOIGNITION OF WOOD

GLOWING AND FLAMING AUTOIGNITION OF WOOD Proceedings of the Combustion Institute, Volume 29, 2002/pp. 289 296 GLOWING AND FLAMING AUTOIGNITION OF WOOD N. BOONMEE and J. G. QUINTIERE Department of Fire Protection Engineering University of Maryland

More information

Lift-Off and Blow-Out of Under-Expanded Hydrogen Jets: Experiments versus Simulations

Lift-Off and Blow-Out of Under-Expanded Hydrogen Jets: Experiments versus Simulations Lift-Off and Blow-Out of Under-Expanded Hydrogen Jets: Experiments versus Simulations Shentsov V. 1, *, Sakatsume R. 2, Makarov D. 1, Takeno K. 2, Molkov V. 1 1 University of Ulster, Hydrogen Safety Engineering

More information

7.2 Sublimation. The following assumptions are made in order to solve the problem: Sublimation Over a Flat Plate in a Parallel Flow

7.2 Sublimation. The following assumptions are made in order to solve the problem: Sublimation Over a Flat Plate in a Parallel Flow 7..1 Sublimation Over a Flat Plate in a Parallel Flow The following assumptions are made in order to solve the problem: 1.. 3. The flat plate is very thin and so the thermal resistance along the flat plate

More information

Smoldering combustion of incense sticks - experiments and modeling

Smoldering combustion of incense sticks - experiments and modeling Smoldering combustion of incense sticks - experiments and modeling H. S. Mukunda*, J. Basani*, H. M. Shravan** and Binoy Philip*, May 30, 2007 Abstract This paper is concerned with the experimental and

More information

CFD Study of Combustion Behavior of Single and 3 3 Arrayed Huge Oil Tanks in Free Burning and Whirling Conditions

CFD Study of Combustion Behavior of Single and 3 3 Arrayed Huge Oil Tanks in Free Burning and Whirling Conditions CFD Study of Combustion Behavior of Single and 3 3 Arrayed Huge Oil Tanks in Free Burning and Whirling Conditions Satoh K., Liu N. A.*, Lei J., Xie X., Gao W. State Key Laboratory of Fire Science, University

More information

Flame Spread and Extinction over Thermally Thick PMMA in Low Oxygen Concentration Flow

Flame Spread and Extinction over Thermally Thick PMMA in Low Oxygen Concentration Flow Flame Spread and Extinction over Thermally Thick PMMA in Low Oxygen Concentration Flow Y. KUDO, M. ITAKURA, Y. FUJITA, and A. ITO Faculty of Science and Technology Hirosaki University 3 Bunkyo-cho Hirosaki,

More information

Lower limit of weak flame in a heated channel

Lower limit of weak flame in a heated channel Lower limit of weak flame in a heated channel Yosuke Tsuboi, Takeshi Yokomori*, Kaoru Maruta IFS, Tohoku University * Keio University Background No.2 For highly efficient combustion, HiCOT, HCCI, etc -

More information

Ph.D. Qualifying Examination in Heat Transfer

Ph.D. Qualifying Examination in Heat Transfer Student # Department of Mechanical Engineering Michigan State University East Lansing, Michigan Ph.D. Qualifying Examination in Heat Transfer One open book. Answer questions 1 and 4 and either of 2 or

More information

Lecture 7 Flame Extinction and Flamability Limits

Lecture 7 Flame Extinction and Flamability Limits Lecture 7 Flame Extinction and Flamability Limits 7.-1 Lean and rich flammability limits are a function of temperature and pressure of the original mixture. Flammability limits of methane and hydrogen

More information

Laminar Premixed Flames: Flame Structure

Laminar Premixed Flames: Flame Structure Laminar Premixed Flames: Flame Structure Combustion Summer School 2018 Prof. Dr.-Ing. Heinz Pitsch Course Overview Part I: Fundamentals and Laminar Flames Introduction Fundamentals and mass balances of

More information

NUMERICAL RESEARCH OF HEAT AND MASS TRANSFER DURING LOW-TEMPERATURE IGNITION OF A COAL PARTICLE

NUMERICAL RESEARCH OF HEAT AND MASS TRANSFER DURING LOW-TEMPERATURE IGNITION OF A COAL PARTICLE THERMAL SCIENCE: Year 2015, Vol. 19, No. 1, pp. 285-294 285 NUMERICAL RESEARCH OF HEAT AND MASS TRANSFER DURING LOW-TEMPERATURE IGNITION OF A COAL PARTICLE by Dmitrii O. GLUSHKOV *, Pavel A. STRIZHAK,

More information

of Nebraska - Lincoln

of Nebraska - Lincoln University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Combustion Research at University of Nebraska- Lincoln Mechanical & Materials Engineering, Department of March 2006 Raghavan,

More information

Lecture 6 Asymptotic Structure for Four-Step Premixed Stoichiometric Methane Flames

Lecture 6 Asymptotic Structure for Four-Step Premixed Stoichiometric Methane Flames Lecture 6 Asymptotic Structure for Four-Step Premixed Stoichiometric Methane Flames 6.-1 Previous lecture: Asymptotic description of premixed flames based on an assumed one-step reaction. basic understanding

More information

Part II Combustion. Summary. F.A. Williams, T. Takeno, Y. Nakamura and V. Nayagam

Part II Combustion. Summary. F.A. Williams, T. Takeno, Y. Nakamura and V. Nayagam Part II Combustion F.A. Williams, T. Takeno, Y. Nakamura and V. Nayagam Summary Combustion, which involves exothermically chemically reacting flows, is complicated in that it includes both physical processes,

More information

Experimental and Theoretical Study of the Ignition and Smoldering of Wood Including Convective Effects

Experimental and Theoretical Study of the Ignition and Smoldering of Wood Including Convective Effects Experimental and Theoretical Study of the Ignition and Smoldering of Wood Including Convective Effects R. BILBAO,* J. F. MASTRAL, M. E. ALDEA, J. CEAMANOS and M. BETRÁN Department of Chemical and Environmental

More information

Theoretical and Experimental Studies on Transient Heat Transfer for Forced Convection Flow of Helium Gas over a Horizontal Cylinder

Theoretical and Experimental Studies on Transient Heat Transfer for Forced Convection Flow of Helium Gas over a Horizontal Cylinder 326 Theoretical and Experimental Studies on Transient Heat Transfer for Forced Convection Flow of Helium Gas over a Horizontal Cylinder Qiusheng LIU, Katsuya FUKUDA and Zheng ZHANG Forced convection transient

More information

Chapter 1. Introduction to Nonlinear Space Plasma Physics

Chapter 1. Introduction to Nonlinear Space Plasma Physics Chapter 1. Introduction to Nonlinear Space Plasma Physics The goal of this course, Nonlinear Space Plasma Physics, is to explore the formation, evolution, propagation, and characteristics of the large

More information

Opposed-Flow Flame Spread Over Polymeric Materials: Influence of Phase Change

Opposed-Flow Flame Spread Over Polymeric Materials: Influence of Phase Change Opposed-Flow Flame Spread Over Polymeric Materials: Influence of Phase Change GUANYU ZHENG, INDREK S. WICHMAN,* and ANDRÉ BÉNARD Department of Mechanical Engineering, Michigan State University, East Lansing,

More information

Laminar flame speed (burning velocity) reactants. propagating flame front. products. reactants

Laminar flame speed (burning velocity) reactants. propagating flame front. products. reactants Laminar flame speed (burning velocity) Introduction One of the most important parameters, influencing both, the combustion system design and combustion process control, is the flame speed. The flame speed

More information

Period Doubling Cascade in Diffusion Flames

Period Doubling Cascade in Diffusion Flames Period Doubling Cascade in Diffusion Flames Milan Miklavčič Department of Mathematics, Michigan State University, East Lansing, MI 48824, USA Combustion Theory and Modelling 11 No 1 (2007), 103-112 Abstract

More information

Well Stirred Reactor Stabilization of flames

Well Stirred Reactor Stabilization of flames Well Stirred Reactor Stabilization of flames Well Stirred Reactor (see books on Combustion ) Stabilization of flames in high speed flows (see books on Combustion ) Stabilization of flames Although the

More information

Lift-off and blow-out of under-expanded hydrogen jets: experiments versus simulations

Lift-off and blow-out of under-expanded hydrogen jets: experiments versus simulations Lift-off and blow-out of under-expanded hydrogen jets: experiments versus simulations Shentsov, V. 1, Sakatsume, R. 2, Makarov, D. 1, Takeno, K. 2, Molkov, V. 1 1 Hydrogen Safety Engineering and Research

More information

Lecture 8 Laminar Diffusion Flames: Diffusion Flamelet Theory

Lecture 8 Laminar Diffusion Flames: Diffusion Flamelet Theory Lecture 8 Laminar Diffusion Flames: Diffusion Flamelet Theory 8.-1 Systems, where fuel and oxidizer enter separately into the combustion chamber. Mixing takes place by convection and diffusion. Only where

More information

Modeling of the pyrolysis of plywood exposed to heat fluxes under cone calorimeter

Modeling of the pyrolysis of plywood exposed to heat fluxes under cone calorimeter Modeling of the pyrolysis of plywood exposed to heat fluxes under cone calorimeter TALAL FATEH, FRANCK RICHARD, and THOMAS ROGAUME Institut Pprime / Département FTC Téléport 2-1, avenue Clément Ader, 86961

More information

Flame Radiation in Large Fires

Flame Radiation in Large Fires Flame Radiation in Large Fires Wighus R.*, Brandt A. W., Sesseng C. SP Fire Research AS, Fire Development and Mitigation, Trondheim, Norway *Corresponding author email: ragnar.wighus@spfr.no ABSTRACT A

More information

COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF A V-RIB WITH GAP ROUGHENED SOLAR AIR HEATER

COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF A V-RIB WITH GAP ROUGHENED SOLAR AIR HEATER THERMAL SCIENCE: Year 2018, Vol. 22, No. 2, pp. 963-972 963 COMPUTATIONAL FLUID DYNAMICS ANALYSIS OF A V-RIB WITH GAP ROUGHENED SOLAR AIR HEATER by Jitesh RANA, Anshuman SILORI, Rajesh MAITHANI *, and

More information

Critical Conditions for Water-based Suppression of Plastic Pool Fires. H. Li 1, A. S. Rangwala 1 and J.L. Torero 2

Critical Conditions for Water-based Suppression of Plastic Pool Fires. H. Li 1, A. S. Rangwala 1 and J.L. Torero 2 Paper # 070FR-0069 Topic: Fire 8 th U. S. National Combustion Meeting Organized by the Western States Section of the Combustion Institute and hosted by the University of Utah May 19-22, 2013 Critical Conditions

More information

Suppression of Cellular Structure in Slot-Burner Flames

Suppression of Cellular Structure in Slot-Burner Flames Suppression of Cellular Structure in Slot-Burner Flames L. J. ROSEN 1 and R. L. AXELBAUM* Washington University, Department of Mechanical Engineering, St. Louis, MO 63130, USA The mechanisms responsible

More information

Combustion MATHEMATICAL MODEL FOR TRANSIENT. S. M. Frolov Λ,F.S.Frolov Λ, and B. Basara y

Combustion MATHEMATICAL MODEL FOR TRANSIENT. S. M. Frolov Λ,F.S.Frolov Λ, and B. Basara y Combustion MATHEMATICAL MODEL FOR TRANSIENT DROPLET VAPORIZATION S. M. Frolov Λ,F.S.Frolov Λ, and B. Basara y Λ N. N. Semenov Institute of Chemical Physics Russian Academy of Sciences Moscow, Russia y

More information

EXPERIMENTAL AND NUMERICAL STUDIES FOR FLAME SPREAD OVER A FINITE-LENGTH PMMA WITH RADIATION EFFECT

EXPERIMENTAL AND NUMERICAL STUDIES FOR FLAME SPREAD OVER A FINITE-LENGTH PMMA WITH RADIATION EFFECT ISTP-16, 2005, PRAGUE 16 TH INTERNATIONAL SYMPOSIUM ON TRANSPORT PHENOMENA EXPERIMENTAL AND NUMERICAL STUDIES FOR FLAME SPREAD OVER A FINITE-LENGTH PMMA WITH RADIATION EFFECT Wen-Kuei Chang and Chiun-Hsun

More information

Review of temperature distribution in cathode of PEMFC

Review of temperature distribution in cathode of PEMFC Project Report 2008 MVK 160 Heat and Mass Transport May 08, 2008, Lund, Sweden Review of temperature distribution in cathode of PEMFC Munir Ahmed Khan Department of Energy Sciences, Lund Institute of Technology,

More information

Transactions on Engineering Sciences vol 5, 1994 WIT Press, ISSN

Transactions on Engineering Sciences vol 5, 1994 WIT Press,  ISSN Smolder spread through thin horizontal fuel layers C. Di Blasi Dipartimento di Ingegneria Chimica, Universitd degli Studi di Napoli Federico II, PmzWe 7. Tecc/wo, (90^^5 Mzpo/z, 7(a/?/ ABSTRACT Two-dimensional

More information

A Numerical Study of Forced Convection Heat Transfer for Staggered Tube Banks in Cross-Flow

A Numerical Study of Forced Convection Heat Transfer for Staggered Tube Banks in Cross-Flow A Numerical Study of Forced Convection Heat Transfer for Staggered Tube Banks in Cross-Flow T. A. Tahseen 1, M. Ishak 1,2 and M. M. Rahman 1,2 1 Faculty of Mechanical Engineering, University Malaysia Pahang

More information

Convective Vaporization and Burning of Fuel Droplet Arrays

Convective Vaporization and Burning of Fuel Droplet Arrays Convective Vaporization and Burning of Fuel Droplet Arrays Guang Wu and William A. Sirignano Mechanical & Aerospace Engineering University of California, Irvine May 19, 2009 Background and Task In many

More information

Multiphase CFD Model of Wildland Fire Initiation and Spread

Multiphase CFD Model of Wildland Fire Initiation and Spread The 5th International Fire Behavior and Fuels Conference April 11-15, 2016, Portland, Oregon, USA Multiphase CFD Model of Wildland Fire Initiation and Spread 1 Vladimir Agranat, Ph.D. President & Senior

More information

Contribution of Gas-phase Reaction on Heat Output from Smoldering Packed-bed of Dried Leaves INOUE, Yasunobu* 1,2, SUZUKI, Masataro 2 1

Contribution of Gas-phase Reaction on Heat Output from Smoldering Packed-bed of Dried Leaves INOUE, Yasunobu* 1,2, SUZUKI, Masataro 2 1 Contribution of Gas-phase Reaction on Heat Output from Smoldering Packed-bed of Dried Leaves INOUE, Yasunobu* 1,2, SUZUKI, Masataro 2 1 Japan Tobacco Inc. Tobacco Science Research Center 2 Nagaoka University

More information

6.2 Governing Equations for Natural Convection

6.2 Governing Equations for Natural Convection 6. Governing Equations for Natural Convection 6..1 Generalized Governing Equations The governing equations for natural convection are special cases of the generalized governing equations that were discussed

More information

Flame Propagation in Poiseuille Flow under Adiabatic Conditions

Flame Propagation in Poiseuille Flow under Adiabatic Conditions Flame Propagation in Poiseuille Flow under Adiabatic Conditions J. DAOU and M. MATALON* Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL 60208-3125, USA

More information

Development of One-Step Chemistry Models for Flame and Ignition Simulation

Development of One-Step Chemistry Models for Flame and Ignition Simulation Development of One-Step Chemistry Models for Flame and Ignition Simulation S.P.M. Bane, J.L. Ziegler, and J.E. Shepherd Graduate Aerospace Laboratories California Institute of Technology Pasadena, CA 91125

More information

ADVANCED DES SIMULATIONS OF OXY-GAS BURNER LOCATED INTO MODEL OF REAL MELTING CHAMBER

ADVANCED DES SIMULATIONS OF OXY-GAS BURNER LOCATED INTO MODEL OF REAL MELTING CHAMBER ADVANCED DES SIMULATIONS OF OXY-GAS BURNER LOCATED INTO MODEL OF REAL MELTING CHAMBER Ing. Vojtech Betak Ph.D. Aerospace Research and Test Establishment Department of Engines Prague, Czech Republic Abstract

More information

EFFECTS OF FINITE SAMPLE WIDTH ON TRANSITION AND FLAME SPREAD IN MICROGRAVITY

EFFECTS OF FINITE SAMPLE WIDTH ON TRANSITION AND FLAME SPREAD IN MICROGRAVITY Proceedings of the Combustion Institute, Volume 28, 2000/pp. 2785 2792 EFFECTS OF FINITE SAMPLE WIDTH ON TRANSITION AND FLAME SPREAD IN MICROGRAVITY W. E. MELL 1 and T. KASHIWAGI 2 1 Mechanical Engineering

More information

External Forced Convection :

External Forced Convection : External Forced Convection : Flow over Bluff Objects (Cylinders, Spheres, Packed Beds) and Impinging Jets Chapter 7 Sections 7.4 through 7.8 7.4 The Cylinder in Cross Flow Conditions depend on special

More information

Effects of heat and momentum losses on the stability of premixed flames in a narrow channel

Effects of heat and momentum losses on the stability of premixed flames in a narrow channel Combustion Theory and Modelling Vol. 10, No. 4, August 2006, 659 681 Effects of heat and momentum losses on the stability of premixed flames in a narrow channel S. H. KANG,S.W.BAEK and H. G. IM Aeropropulsion

More information

POSTER PAPER PROCEEDINGS

POSTER PAPER PROCEEDINGS ITA - AITES WORLD TUNNEL CONGRESS 21-26 April 2018 Dubai International Convention & Exhibition Centre, UAE POSTER PAPER PROCEEDINGS Flow and temperature characteristics around a burning car in a long tunnel

More information

Laminar flow heat transfer studies in a twisted square duct for constant wall heat flux boundary condition

Laminar flow heat transfer studies in a twisted square duct for constant wall heat flux boundary condition Sādhanā Vol. 40, Part 2, April 2015, pp. 467 485. c Indian Academy of Sciences Laminar flow heat transfer studies in a twisted square duct for constant wall heat flux boundary condition RAMBIR BHADOURIYA,

More information

Lecture 12. Droplet Combustion Spray Modeling. Moshe Matalon

Lecture 12. Droplet Combustion Spray Modeling. Moshe Matalon Lecture 12 Droplet Combustion Spray Modeling Spray combustion: Many practical applications liquid fuel is injected into the combustion chamber resulting in fuel spray. Spray combustion involves many physical

More information

THE EFFECTS OF AIR-BORNE WATER MIST ON THE LOCAL BURNING RATE OF A PMMA PLATE IN BOUNDARY LAYER COMBUSTION

THE EFFECTS OF AIR-BORNE WATER MIST ON THE LOCAL BURNING RATE OF A PMMA PLATE IN BOUNDARY LAYER COMBUSTION THE EFFECTS OF AIR-BORNE WATER MIST ON THE LOCAL BURNING RATE OF A PMMA PLATE IN BOUNDARY LAYER COMBUSTION C.C. Ndubizu (cndubizu@castor.nrl.navy.mil 202-767-2766) Geo-Centers Inc. Lahnam, MD R Ananth

More information

a 16 It involves a change of laminar burning velocity, widening or narrowing combustion limits for

a 16 It involves a change of laminar burning velocity, widening or narrowing combustion limits for Peculiarities of filtration combustion of hydrogen-, propane- and methane-air mixtures in inert porous media. Kakutkina N.A., Korzhavin A.A., Mbarawa M. * Institute of chemical kinetics and combustion

More information

A MODEL OF SMOKE MOVEMENT IN STAIR SHAFTS

A MODEL OF SMOKE MOVEMENT IN STAIR SHAFTS A MODEL OF SMOKE MOVEMENT IN STAIR SHAFTS Daisaku Nii 1,4, Noe Takehira 1, Kazunori Harada 1,, Yoshifumi Ohmiya 2, Toshio Yamana 3 and Ichiro Hagiwara 3 1 Department of Architecture and Environmental Design,

More information

Theoretical Developments in Group Combustion of Droplets and Sprays

Theoretical Developments in Group Combustion of Droplets and Sprays Theoretical Developments in Group Combustion of Droplets and Sprays William A. Sirignano University of California, Irvine Collaborations: Guang Wu, current student; Randall Imaoka, former student, US Navy;

More information

Exergy Analysis of Solar Air Collector Having W Shaped Artificial Roughness

Exergy Analysis of Solar Air Collector Having W Shaped Artificial Roughness Advances in Materials Science and Mechanical Engineering Research Volume 1, Number 1 (2015), pp. 25-32 International Research Publication House http://www.irphouse.com Exergy Analysis of Solar Air Collector

More information

FIND: (a) Sketch temperature distribution, T(x,t), (b) Sketch the heat flux at the outer surface, q L,t as a function of time.

FIND: (a) Sketch temperature distribution, T(x,t), (b) Sketch the heat flux at the outer surface, q L,t as a function of time. PROBLEM 5.1 NOWN: Electrical heater attached to backside of plate while front surface is exposed to convection process (T,h); initially plate is at a uniform temperature of the ambient air and suddenly

More information

MIXED CONVECTION SLIP FLOW WITH TEMPERATURE JUMP ALONG A MOVING PLATE IN PRESENCE OF FREE STREAM

MIXED CONVECTION SLIP FLOW WITH TEMPERATURE JUMP ALONG A MOVING PLATE IN PRESENCE OF FREE STREAM THERMAL SCIENCE, Year 015, Vol. 19, No. 1, pp. 119-18 119 MIXED CONVECTION SLIP FLOW WITH TEMPERATURE JUMP ALONG A MOVING PLATE IN PRESENCE OF FREE STREAM by Gurminder SINGH *a and Oluwole Daniel MAKINDE

More information

Department of Mechanical Engineering BM 7103 FUELS AND COMBUSTION QUESTION BANK UNIT-1-FUELS

Department of Mechanical Engineering BM 7103 FUELS AND COMBUSTION QUESTION BANK UNIT-1-FUELS Department of Mechanical Engineering BM 7103 FUELS AND COMBUSTION QUESTION BANK UNIT-1-FUELS 1. Define the term fuels. 2. What are fossil fuels? Give examples. 3. Define primary fuels. Give examples. 4.

More information

A Study of Flame Spread in Engineered Cardboard Fuelbeds Part II: Scaling Law Approach

A Study of Flame Spread in Engineered Cardboard Fuelbeds Part II: Scaling Law Approach A Study of Flame Spread in Engineered Cardboard Fuelbeds Part II: Scaling Law Approach Brittany A. Adam (a), Nelson K. Akafuah (a) (*), Mark Finney (b), Jason Forthofer (b), and Kozo Saito (a) (a) Institute

More information

拡散 熱的および流体力学的不安定性のスケール効果

拡散 熱的および流体力学的不安定性のスケール効果 56 176 2014 172-177 Journal of the Combustion Society of Japan Vol.56 No.176 (2014) 172-177 ORIGINAL PAPER 拡散 熱的および流体力学的不安定性のスケール効果 Scale Effects of Diffusive-thermal and Hydrodynamic Instability * SHIBAYAMA,

More information

Conjugate heat transfer from an electronic module package cooled by air in a rectangular duct

Conjugate heat transfer from an electronic module package cooled by air in a rectangular duct Conjugate heat transfer from an electronic module package cooled by air in a rectangular duct Hideo Yoshino a, Motoo Fujii b, Xing Zhang b, Takuji Takeuchi a, and Souichi Toyomasu a a) Fujitsu Kyushu System

More information

Chapter 5 Test. Directions: Write the correct letter on the blank before each question.

Chapter 5 Test. Directions: Write the correct letter on the blank before each question. Chapter 5 Test Name: Date: Directions: Write the correct letter on the blank before each question. Objective 1: Explain the science of fire as it relates to energy, forms of ignition, and modes of combustion.

More information

Fall 2014 Qualifying Exam Thermodynamics Closed Book

Fall 2014 Qualifying Exam Thermodynamics Closed Book Fall 2014 Qualifying Exam Thermodynamics Closed Book Saturated ammonia vapor at 200 O F flows through a 0.250 in diameter tube. The ammonia passes through a small orifice causing the pressure to drop very

More information

Heat Transfer Characteristics of Square Micro Pin Fins under Natural Convection

Heat Transfer Characteristics of Square Micro Pin Fins under Natural Convection Journal of Electronics Cooling and Thermal Control, 2014, 4, 59-69 Published Online September 2014 in SciRes. http://www.scirp.org/journal/jectc http://dx.doi.org/10.4236/jectc.2014.43007 Heat Transfer

More information

Warehouse Commodity Classification from Fundamental Principles. Part II: Flame Heights and Flame Spread

Warehouse Commodity Classification from Fundamental Principles. Part II: Flame Heights and Flame Spread Warehouse Commodity Classification from Fundamental Principles. Part II: Flame Heights and Flame Spread K.J. Overholt a,, M.J. Gollner b, J. Perricone c, A.S. Rangwala a, F.A. Williams b a Worcester Polytechnic

More information

The Effect of Mixture Fraction on Edge Flame Propagation Speed

The Effect of Mixture Fraction on Edge Flame Propagation Speed 8 th U. S. National Combustion Meeting Organized by the Western States Section of the Combustion Institute and hosted by the University of Utah May 19-22, 213 The Effect of Mixture Fraction on Edge Flame

More information

Lecture 9 Laminar Diffusion Flame Configurations

Lecture 9 Laminar Diffusion Flame Configurations Lecture 9 Laminar Diffusion Flame Configurations 9.-1 Different Flame Geometries and Single Droplet Burning Solutions for the velocities and the mixture fraction fields for some typical laminar flame configurations.

More information

Experimental Study of 2D-Instabilities of Hydrogen Flames in Flat Layers

Experimental Study of 2D-Instabilities of Hydrogen Flames in Flat Layers 25 th ICDERS August 2 7, 2015 Leeds, UK Experimental Study of 2D-Instabilities of Hydrogen Flames in Flat Layers M. Kuznetsov 1 *, J. Grune 2, S. Tengah 1, J. Yanez 1 1 Intitute for Energy and Nuclear

More information

The Reaction Pathway Analysis of 2-Bromo-3,3,3-trifluoropropene with the Active Radicals and Pyrolysis of 2-Bromo-3,3,3- trifluoropropene

The Reaction Pathway Analysis of 2-Bromo-3,3,3-trifluoropropene with the Active Radicals and Pyrolysis of 2-Bromo-3,3,3- trifluoropropene The Reaction Pathway Analysis of 2-Bromo-3,3,3-trifluoropropene with the Active Radicals and Pyrolysis of 2-Bromo-3,3,3- trifluoropropene Zhang P. L., Jiang Y., Zhou X. M.* The College of Environmental

More information

Thermo-Fluid Performance of a Vapor- Chamber Finned Heat Sink

Thermo-Fluid Performance of a Vapor- Chamber Finned Heat Sink The Egyptian International Journal of Engineering Sciences and Technology Vol. 20 (July 2016) 10 24 http://www.eijest.zu.edu.eg Thermo-Fluid Performance of a Vapor- Chamber Finned Heat Sink Saeed A.A.

More information

Liquid-Rocket Transverse Triggered Combustion Instability: Deterministic and Stochastic Analyses

Liquid-Rocket Transverse Triggered Combustion Instability: Deterministic and Stochastic Analyses Liquid-Rocket Transverse Triggered Combustion Instability: Deterministic and Stochastic Analyses by W. A. Sirignano Mechanical and Aerospace Engineering University of California, Irvine Collaborators:

More information

5th WSEAS Int. Conf. on Heat and Mass transfer (HMT'08), Acapulco, Mexico, January 25-27, 2008

5th WSEAS Int. Conf. on Heat and Mass transfer (HMT'08), Acapulco, Mexico, January 25-27, 2008 Numerical Determination of Temperature and Velocity Profiles for Forced and Mixed Convection Flow through Narrow Vertical Rectangular Channels ABDALLA S. HANAFI Mechanical power department Cairo university

More information

Modeling and Simulation of Plasma-Assisted Ignition and Combustion

Modeling and Simulation of Plasma-Assisted Ignition and Combustion Modeling and Simulation of Plasma-Assisted Ignition and Combustion Vigor Yang and Sharath Nagaraja Georgia Institute of Technology Atlanta, GA AFOSR MURI Fundamental Mechanisms, Predictive Modeling, and

More information

Numerical Examination of Two-Dimensional Smolder Structure in Polyurethane Foam

Numerical Examination of Two-Dimensional Smolder Structure in Polyurethane Foam Numerical Examination of Two-Dimensional Smolder Structure in Polyurethane Foam A. B. Dodd 1,2,a, C. Lautenberger 2, and A.C. Fernandez-Pello 2 1 Sandia National Laboratories b, Albuquerque, NM, 87185

More information

CHME 302 CHEMICAL ENGINEERING LABOATORY-I EXPERIMENT 302-V FREE AND FORCED CONVECTION

CHME 302 CHEMICAL ENGINEERING LABOATORY-I EXPERIMENT 302-V FREE AND FORCED CONVECTION CHME 302 CHEMICAL ENGINEERING LABOATORY-I EXPERIMENT 302-V FREE AND FORCED CONVECTION OBJECTIVE The objective of the experiment is to compare the heat transfer characteristics of free and forced convection.

More information

Department of Mechanical Engineering, University Visvesvaraya College of Engineering, Bangalore University, Bangalore, Karnataka, India

Department of Mechanical Engineering, University Visvesvaraya College of Engineering, Bangalore University, Bangalore, Karnataka, India EXPERIMENTAL INVESTIGATION ON EFFECTS OF HEAT FLUX AND DENSITY ON SMOLDERING OF COTTON Ramesh D K *1, Manjunath S O #1, Sanjay R #2, Sai Naveen S #3, Jayantha #4 * Associate professor, # BE Scholar Department

More information

INTRODUCTION TO CATALYTIC COMBUSTION

INTRODUCTION TO CATALYTIC COMBUSTION INTRODUCTION TO CATALYTIC COMBUSTION R.E. Hayes Professor of Chemical Engineering Department of Chemical and Materials Engineering University of Alberta, Canada and S.T. Kolaczkowski Professor of Chemical

More information

Available online at ScienceDirect. Nuclear power plant explosions at Fukushima-Daiichi. Takashi Tsuruda*

Available online at   ScienceDirect. Nuclear power plant explosions at Fukushima-Daiichi. Takashi Tsuruda* Available online at www.sciencedirect.com ScienceDirect Procedia Engineering 62 ( 2013 ) 71 77 The 9 th Asia-Oceania Symposium on Fire Science and Technology Nuclear power plant explosions at Fukushima-Daiichi

More information

Dispersion relations for the convective instability of an acidity front in Hele-Shaw cells

Dispersion relations for the convective instability of an acidity front in Hele-Shaw cells JOURNAL OF CHEMICAL PHYSICS VOLUME 121, NUMBER 2 8 JULY 2004 Dispersion relations for the convective instability of an acidity front in Hele-Shaw cells Desiderio A. Vasquez Department of Physics, Indiana

More information

Edges of flames that do not exist: flame-edge dynamics in a non-premixed counterflow

Edges of flames that do not exist: flame-edge dynamics in a non-premixed counterflow Combust. Theory Modelling 4 (2000) 435 457. Printed in the UK PII: S1364-7830(00)11525-6 Edges of flames that do not exist: flame-edge dynamics in a non-premixed counterflow R W Thatcher and J W Dold Mathematics

More information

A Methodology for Estimation of Local Heat Fluxes in Steady Laminar Boundary Layer Diffusion Flames

A Methodology for Estimation of Local Heat Fluxes in Steady Laminar Boundary Layer Diffusion Flames A Methodology for Estimation of Local Heat Fluxes in Steady Laminar Boundary Layer Diffusion Flames Ajay V. Singh a, Michael J. Gollner a a University of Maryland, College Park, Dept. of Fire Protection

More information

Parallel Plate Heat Exchanger

Parallel Plate Heat Exchanger Parallel Plate Heat Exchanger Parallel Plate Heat Exchangers are use in a number of thermal processing applications. The characteristics are that the fluids flow in the narrow gap, between two parallel

More information

Analysis of Heat Transfer in Pipe with Twisted Tape Inserts

Analysis of Heat Transfer in Pipe with Twisted Tape Inserts Proceedings of the 2 nd International Conference on Fluid Flow, Heat and Mass Transfer Ottawa, Ontario, Canada, April 30 May 1, 2015 Paper No. 143 Analysis of Heat Transfer in Pipe with Twisted Tape Inserts

More information

Quenching and propagation of combustion fronts in porous media

Quenching and propagation of combustion fronts in porous media Quenching and propagation of combustion fronts in porous media Peter Gordon Department of Mathematical Sciences New Jersey Institute of Technology Newark, NJ 72, USA CAMS Report 56-6, Spring 26 Center

More information

MODELLING THE IMPACT OF RADIATIVE HEAT LOSS ON CO 2 EMISSION, O 2 DEPLETION AND THERMAL STABILITY IN A REACTIVE SLAB *

MODELLING THE IMPACT OF RADIATIVE HEAT LOSS ON CO 2 EMISSION, O 2 DEPLETION AND THERMAL STABILITY IN A REACTIVE SLAB * IJST, Transactions of Mechanical Engineering, Vol. 39, No. M2, pp 351-365 Printed in The Islamic Republic of Iran, 2015 Shiraz University MODELLING THE IMPACT OF RADIATIVE HEAT LOSS ON CO 2 EMISSION, O

More information

CFD SIMULATION OF HYDROGEN RELEASE, DISPERSION AND AUTO-IGNITION IN ENCLOSURES

CFD SIMULATION OF HYDROGEN RELEASE, DISPERSION AND AUTO-IGNITION IN ENCLOSURES MCS 7 Chia Laguna, Cagliari, Sardinia, Italy, September 11-15, 2011 CFD SIMULATION OF HYDROGEN RELEASE, DISPERSION AND AUTO-IGNITION IN ENCLOSURES T. Bar-Kohany * and K. Dahan * kahany@bgu.ac.il *Mechanical

More information

EXPERIMENTS WITH RELEASE AND IGNITION OF HYDROGEN GAS IN A 3 M LONG CHANNEL

EXPERIMENTS WITH RELEASE AND IGNITION OF HYDROGEN GAS IN A 3 M LONG CHANNEL EXPERIMENTS WITH RELEASE AND IGNITION OF HYDROGEN GAS IN A 3 M LONG CHANNEL Sommersel, O. K. 1, Bjerketvedt, D. 1, Vaagsaether, K. 1, and Fannelop, T.K. 1, 2 1 Department of Technology, Telemark University

More information

Pyrolysis Modelling of PVC Cable Materials

Pyrolysis Modelling of PVC Cable Materials Pyrolysis Modelling of PVC Cable Materials ANNA MATALA, and SIMO HOSTIKKA VTT Technical Research Centre of Finland P.O.Box 1000 FI-02044 VTT, Finland ABSTRACT One of the most commonly used materials in

More information

THE EFFECT OF LIQUID FILM EVAPORATION ON FLOW BOILING HEAT TRANSFER IN A MICRO TUBE

THE EFFECT OF LIQUID FILM EVAPORATION ON FLOW BOILING HEAT TRANSFER IN A MICRO TUBE Proceedings of the International Heat Transfer Conference IHTC14 August 8-13, 2010, Washington, DC, USA IHTC14-22751 THE EFFECT OF LIQUID FILM EVAPORATION ON FLOW BOILING HEAT TRANSFER IN A MICRO TUBE

More information

ONE-DIMENSIONAL MODEL OF PYROLYSIS AND IGNITION OF MEDIUM DENSITY FIBERBOARD SUBJECTED TO TRANSIENT IRRADIATION

ONE-DIMENSIONAL MODEL OF PYROLYSIS AND IGNITION OF MEDIUM DENSITY FIBERBOARD SUBJECTED TO TRANSIENT IRRADIATION ONE-DIMENSIONAL MODEL OF PYROLYSIS AND IGNITION OF MEDIUM DENSITY FIBERBOARD SUBJECTED TO TRANSIENT IRRADIATION Izabella Vermesi, Gaurav Agarwal, Marcos Chaos, and Guillermo Rein 1 Imperial College London

More information

Flashover Fires in Small Residential Units with an Open Kitchen

Flashover Fires in Small Residential Units with an Open Kitchen 1 Flashover Fires in Small Residential Units with an Open Kitchen J. Liu 1 and W.K. Chow 2 PhD Student, Department of Building Services Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon,

More information

Asymptotic Structure of Rich Methane-Air Flames

Asymptotic Structure of Rich Methane-Air Flames Asymptotic Structure of Rich Methane-Air Flames K. SESHADRI* Center for Energy and Combustion Research, Department of Mechanical and Aerospace Engineering, University of California at San Diego, La Jolla,

More information

FLAME SPREAD AND EXTINCTION OVER SOLIDS IN BUOYANT AND FORCED CONCURRENT FLOWS: MODEL COMPUTATIONS AND COMPARISON WITH EXPERIMENTS

FLAME SPREAD AND EXTINCTION OVER SOLIDS IN BUOYANT AND FORCED CONCURRENT FLOWS: MODEL COMPUTATIONS AND COMPARISON WITH EXPERIMENTS FLAME SPREAD AND EXTINCTION OVER SOLIDS IN BUOYANT AND FORCED CONCURRENT FLOWS: MODEL COMPUTATIONS AND COMPARISON WITH EXPERIMENTS by SHENG-YEN HSU Submitted in partial fulfillment of the requirements

More information

Laboratory Studies of Fire Whirls (preliminary)

Laboratory Studies of Fire Whirls (preliminary) Laboratory Studies of Fire Whirls (preliminary) Alexander J. Smits, Katie A. Hartl, Stacy Guo and Frederick L. Dryer Princeton University Coupled Atmosphere Bushfire Modelling Workshop 16 18 May 2012 High

More information

Laminar Diffusion Flame Shapes Under Earth- Gravity and Microgravity Conditions

Laminar Diffusion Flame Shapes Under Earth- Gravity and Microgravity Conditions Laminar Diffusion Flame Shapes Under Earth- Gravity and Microgravity Conditions Jason Abshire Graduate Research Assistant Sivakumar Krishnan Assistant Professor, (Advisor) 1 Outline Motivation, Background,

More information

Sandwich Propellant Combustion

Sandwich Propellant Combustion Sandwich Propellant Combustion P. A. Ramakrishna, P. J. Paul and H. S. Mukunda Combustion Gasification and Propulsion Laboratory Department of Aerospace Engineering Indian Institute of Science Bangalore

More information

Pattern formation of flames in radial microchannels with lean methane-air mixtures

Pattern formation of flames in radial microchannels with lean methane-air mixtures Pattern formation of flames in radial microchannels with lean methane-air mixtures Sudarshan Kumar, 1 Kaoru Maruta, 1 and S. Minaev 2 1 Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku,

More information

AME 513. " Lecture 7 Conservation equations

AME 513.  Lecture 7 Conservation equations AME 51 Principles of Combustion Lecture 7 Conservation equations Outline Conservation equations Mass Energy Chemical species Momentum 1 Conservation of mass Cubic control volume with sides dx, dy, dz u,

More information

Flame / wall interaction and maximum wall heat fluxes in diffusion burners

Flame / wall interaction and maximum wall heat fluxes in diffusion burners Flame / wall interaction and maximum wall heat fluxes in diffusion burners de Lataillade A. 1, Dabireau F. 1, Cuenot B. 1 and Poinsot T. 1 2 June 5, 2002 1 CERFACS 42 Avenue Coriolis 31057 TOULOUSE CEDEX

More information

CFD Analysis for Thermal Behavior of Turbulent Channel Flow of Different Geometry of Bottom Plate

CFD Analysis for Thermal Behavior of Turbulent Channel Flow of Different Geometry of Bottom Plate International Journal Of Engineering Research And Development e-issn: 2278-067X, p-issn: 2278-800X, www.ijerd.com Volume 13, Issue 9 (September 2017), PP.12-19 CFD Analysis for Thermal Behavior of Turbulent

More information

Premixed, Nonpremixed and Partially Premixed Flames

Premixed, Nonpremixed and Partially Premixed Flames Premixed, Nonpremixed and Partially Premixed Flames Flame (Reaction Zone) Flame (Reaction Zone) Flame (Reaction Zone) Fuel Air Fuel + Air φ 1 Products Fuel + Air φ > 1 F + A Air (+ F?) NONPREMIXED PREMIXED

More information

Advances in Fluid Mechanics and Heat & Mass Transfer

Advances in Fluid Mechanics and Heat & Mass Transfer Performance Study of Nozzle Geometry on Heat Transfer Characteristics Part I: Local Heat Transfer M. Attalla Mechanical Power and Energy Department, Faculty of Engineering, South Valley University, Qena

More information