EE-489 Modeling Project: Behavior of the. Temperature Changes in a Room

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "EE-489 Modeling Project: Behavior of the. Temperature Changes in a Room"

Transcription

1 EE-489 Modeling Project: Behavior of the 1 Temperature Changes in a Room Younes Sangsefidi, Saleh Ziaieinejad, Tarik Wahidi, and Takouda Pidename, Abstract A precise heat flow model, which predicts the temperature changes in a building, is necessary in the design of buildings This report develops a heat flow medel to study the behavior of the temperature of a room when the window is opened First, a simple dynamic model for analyzing the air exchange of the room air with the outside, which is caused by a window opening, is studied Based on this model, a heat flow model is developed The developed heat flow model is implemented in MATLAB to study the temperature changes of the studied room The effectiveness of the proposed model and the presented simulation results are validated by an experimental setup using an ACURITE thermometer Based on the simulation and experimental results, some suggestions are discussed to improve the accuracy of the proposed model I INTRODUCTION Modeling and optimizing residential heat transfer is challenging and at the same time requires understanding of different physical models, their behavior and dynamics Research and experiments have been carried out in particular to understand the dynamics and save energy Heat loss or transfer from a room within a house or outside is well described by three mechanisms namely; conduction, convection and radiation It can be individual mechanism or combination of each In a room heat is transferred by conduction through solids such as windows, walls, roof and floor Heat lost by convection is leaking warm air to outside through windows and doors cracks and when they are open [1] A well-insulated room which means higher R-value of the material that the home is built from plays important role in transfer of heat The industry has characterized the R-value for different type of material In a room, windows offer least resistance to heat transfer and one third of the heat loss in winter occurs through windows [2] To better understand heat transfer through a window in a room, one must S Ziaeinejad, Y Sangsefidi, T Wahidi and T Pidename are with the School of Electrical Engineering and Computer Sience, Washington State University, Pullman, WA, (

2 develop an appropriate model that closely matches the physical characteristics of the room and the opening of window with respect to its area The behavior of the air flow to the room when a door is opened is studied in [3] Reference [3] shows that the air flows to the room in two phases: in the first phase, the constant air flow fills the room from the floor When the middle of the door is reached, the air flow continues in the second phase In the second phase, the air flow decreases exponentially until the upper level of the opening is reached Based on the model proposed in [3] for air flow when a door is opened, [4] proposes a model for the air flow to the room when a window is opened Reference [4] shows that the air flow to the room occurs in two phases: a constant air flow until the lower level of the opening is reached, and a decreasing air flow until the upper level of the opening is reached This report describes the model proposed in [4] for the air flow to the room when a window is opened, and shows that since that model does not consider the temperature changes, it cannot accurately model the air flow when the window is opened for a long time In addition, it cannot model the heat flow inside the room This report modifies the air flow model proposed in [4] and augments it with heat flow equations It will be shown that the result of this modification is coupled equations for modeling air flow and heat flow This report also presents the simulation results of the developed air flow and heat flow model, and validates the model and the simulation results by experimental results This report is organized as follows Section II describes the air flow model previously proposed in the literature Section III modifies the air flow model and augments the developed air flow model with a heat flow model Section IV presents the simulation and experimental results Section V discusses the results and suggests for improvement of the proposed model Section VI concludes the report II DESCRIPTION OF THE AIR FLOW MODEL PROPOSED IN [4] Reference [4] assumes that the opening is vertical, which is a sensible assumption for a window It assumes that there is no wind outside, and the mechanism for air flow into the room is the difference between the temperatures of the outdoor air and inside air The outside temperature is assumed to be constant and less than the temperature inside the room This is a valid assumption during the winter Reference [4] assumes that the window is open only for a short interval It is assumed that during this interval there is no heat transfer inside the room, and therefore the room temperature is constant Since it is assumed that there is no heat transfer, the temperature of the air flowing to the room is constant and equal to the outdoor temperature When the cold air flows into the room, it starts filling the room volume from the floor upwards At the same time, the warm air near the ceiling flows outside 2

3 the room Until the cold air level reaches to the lower level of the window, the air flow rate can be expressed as [5] B V in = C d g 3 H 0 3 (1) Where V in ( m3 s ) is the rate of the air volume flowing to the room, C d is the "opening orifice constant", which equals C d = (T in T out ), (2) Where T in is the temperature inside the room (K), and T out is the outdoor air temperature (K) In (1), B is the width of the opening and H 0 is the height of the opening g can be expressed as g = g 2(T in T out ) T in + T out, (3) where g is the acceleration due to gravity, and approximately equals 981 m s 2 After the cold air reaches to the lower level of the window (beginning of the second phase), the air flow rate can be expressed as where H(t) equals B V in (t) = C d g H(t) 3, (4) 3 H(t) = 1 ( at ) 2, (5) H0 where a equals B B a = C d g = C d g 2(T in T out ), (6) 3A g 3A g T in + T out where A g is the room floor area As the time passes, H(t) becomes smaller and V in (t) decreases 3

4 Fig 1 n layers of the room air III DEVELOPING A COUPLED HEAT AND AIRFLOW MODEL The air flow model described in Section II is valid only if the window is open for a short interval In case that the window is opened for a long time, the assumption of a constant room temperature is not valid In addition, we can not assume that the air that has entered the room will stay near the floor for ever Therefore, it is needed to augment the air flow model with a heat model This results coupled equations Since the heat flow leads to movements of the air molecules, it is impossible to find the location of the air which has entered the room Therefore, it is impossible to distinguish between different phases of the air flow For simplicity, it is assumed that during the entire process, the air flow happens in phase 1 There is no assumption of constant room temperature It is assumed that except for the open window, there is no heat transfer between the air inside the room and the outside All the walls and doors are assumed to be ideally insulated It is assumed that different points with the same height have the same temperature As shown in Fig 1, we can partition the room into n layers, all with the same thickness It is assumed that the incoming cold air goes below the first layer, and affects the temperature of the first layer Because of the differences in the air density, l 1 is the coldest layer, and l n is the warmest When the outdoor air enters the room, it is replaced with a volume of the n th layer air Therefore, the rate of the heat transferred to l 1 from the outdoor air is Q in = ṁ in (t)c air (T OUT T n ) = V in (t)ρ air C air (T OUT T n ) (7) In (7), ρ air and C air are the density and specific heat capacity of the air T n is the temperature of the last layer, and V in (t) equals V in (t) = (T 1 T out ) B 3 4 2g (T in T out ) T in + T out H(t) 3 (8)

5 The rate of the heat transferred to each layer can be found by subtracting the rate of the heat coming from the bottom layer and the rate of the heat going to the upper layer Q 1 (t) = Q in (t) Q 12 (t) Q 2 (t) = Q 12 (t) Q 23 (t) Q 3 (t) = Q 23 (t) Q 34 (t) (9) Q n 1 (t) = Q (n 2)(n 1) (t) Q (n 1)n (t) Q n (t) = Q (n 1)(n) (t) Assuming l i and l i+1 are two adjacent layers, convection, which can be expressed by Q i(i+1) (t) is the convective heat transferred by the Q i(i+1) (t) = h c A g (T i T i+1 ) (10) where h c is the convective heat transfer coefficient After finding the rate of the heat transferred to each layer, the rate of the change in the temperature of that layer is T i (t) = where V l is the volume of each layer, and equals Q i (t) ρ air V l C a ir (11) V l = V room n = L roomw room H room n where L room, W room, and H room are length, width, and height of the room, respectively The behavior of the room temperature after opening the window can be simulated by the Euler method, as described below 1) T 1, T 2,,T n are considered as state variables The initial values of all the state variables are equal to the steady-state room temperature before the window is opened (12) T 0 1 = T 0 2 = = T 0 n = T 0 in,steady state (13) 5

6 2) The sampling time for simulation is chosen t At the k th sampling time, Q k in is calculated from (7) Then, the temperature vector [ T k+1 1 T k+1 1 T k+1 n ] T (14) can be found by T k+1 1 T k+1 2 T k+1 n = T k 1 T k 2 T k n + T k 1 T k 2 T k n t (15) where T k 1 T k 2 T k 3 T k n 1 T k n = h ca g ρv l C air T k 1 T k 2 T k 3 T k n 1 T k n + 1 ρv l C air Q k in (16) Equation (16) is nonlinear because Q k in is a nonlinear function of the states and the input of the system (B) The output of the system y k equals y k = selector 1 n T k 1 T k 2 T k n (17) where selector 1 n is a 1 n matrix Except one entry of selector which is 1, the other entries are zero To form selector 1 n, we should find the layer that inclused our point The entry of selector 1 n 6

7 TABLE I DIMENTIONS AND THE PARAMETERS OF THE SYSTEM Room length, L room Room width, W room Room length, H room Window width, B Window length, H 0 Window height from the ground, H w Test point height from the ground, H point 338 m 310 m 240 m 0272 m or 0544 m 1126 m 1 m 1 m Convective heat transfer coefficient, h c 5 Specific heat capacity of the air, C air Density of the air, ρ air Outside temperature, T out Joule m 2 s C 1000 Joule kg C 129 kg m 3 8 C Room temperature before opening the window, T in,0 267 C which corresponds to that layer is chosen 1 the other entries are chosen 0 After finding y 1,y 2,,y k,, we can plot y (the temperature of our selected point) as a function of time IV SIMULATION AND EXPERIMENTAL RESULTS To study the performance of the proposed temperature model, the model is simulated using MATLAB The parameters of the system are shown in Table I In the first simulation case study, the window is opened 0272 m In this case, the room is devided to 5 layers Fig 2(a) shows the volume of the air entered the room from the outside It can be seen that when the difference between the temperatures of the room and outside decreases, the air flow rate decreases Fig 2(b) shows the temperature of 5 different layers As expected, the temperature of the bottom layers decreases faster The reason is that the cold air stays at the bottom of the room Fig 3 shows the simulation results of the temperature changes when the window is opened 0272 m and the number of layers is defined 10 By increasing the number of layers, it is easier to predict the temperature of different points in the room with higher accuracy In this case study, lower layers still have faster decreases in their temperatures Fig 4 shows the simulation results of the temperature changes when the width of the window opening is set to 0544 m The number of layers is defined 10 It can be observed that a larger opening leads to faster decrease in the temperatures of all layers Figs 2, 3, and 4 show the first few minutes of the experiment, which is good for observing the differences of the temperatures of different layers at the beginning of the experiment The temperatures of all layers finally converge to T out Since the doors 7

8 Fig 2 Simulation results for B = 0272 m; (a) volume of the air entered the room from outside and (b) temperature of five different layers of the room Fig 3 Simulation results of the temperature of ten different layers of the room for B = 0272 m and walls are assumed to be ideally insulated, it is expected that the temperatures of all the points inside the room eventually become equal to T out To validate the proposed model, an experiment is performed and the temperature is monitored using an ACURITE thermometer, which is shown in Fig 5 The parameters of the experiment are similar to the parameters listed in Table I The width of the window opening is B = 0272 m and the thermometer sensor is mounted at the height of 082 m Fig 6 shows the experimental result It can be seen that in the first minutes of the test, there is a good agreement between the simulation and 8

9 Fig 4 Simulation results of the temperature of ten different layers of the room for B = 0544 m Fig 5 Configuration of the test setup experimental results In the first few minutes of the experiment, the difference between the room temperature and the temperatures of different parts of the house is small Therefore, the heat transfer from the walls and the door is negligible, and the model assumption (perfect insulation) is almost valid The agreement between the simulation and experimental results during this period shows the effectiveness of the proposed model However, at the end of the studied period, the difference between simulation and experimental results becomes more significant Although we tried to minimize the heat transfer between the room and other parts of the house, this heat transfer is not zero and it becomes higher when the room temperature becomes much less than the temperature of other parts of the house A precise model should also consider the heat transfers between the room and other parts of the house 9

10 Fig 6 Experimental and simulation results of the temperature of the studied point at the height of 0817 m when B = 0544 m V DISCUSSIONS AND MODEL IMPROVEMENT Based on the discussed model and presented results, there are some suggestion for increasing the accuracy of the model: 1) As previously discussed, there is still a heat transfer between the room and other parts of the house A precise model should also consider the heat transfer through the walls, door, ceiling, floor, and available openings in the room 2) In the proposed model, the density of the air is assumed constant However, it depends on the air temperature and slightly varies with the variation of the temperature It is suggested to consider an adaptive density model based on the temperature 3) In the presented model, the temperature of the points at the same layer are equal However, the points near the window are colder than the points with the same height but far from the window This issue can be considered in the improvement of the model It is possible to divide the room volume into different cubes which transfer the heat with the adjacent cubes from each of their 6 sides This model is more complicated but more accurate VI CONCLUSION This report studies the heat flow between a room and the outside when a window is opened Based on the studied heat flow model, this report presents a method to calculate the profile of the temperatures of different layers of the room The presented model can be defined for different number of layers The effectiveness of the proposed model is validated using simulation and experimental results Based on the results, in a room with an opened window, the decrease in the temperature of the bottom layers 10

11 is more than the decrease in the temperature of the top layers In addition, since there are some heat leakages in the practical case study, after fast transients, the room temperature in experimental case study is higher than the temperature of the simulation case study If the heat flow happens only through the opened window, the model is more precise to predict the temperature Based on the simulation and experimental results, some suggestions are discussed to improve the accuracy of the proposed model VII APPENDIX (MATLAB CODE) The proposed model for analysis of temperature changes is implemented in MATLAB Fig 7 shows the MATLAB code REFERENCES [1] M Rubin, Calculating heat transfer through windows, International Journal of Energy Research, vol 6, no 4, pp , 1982 [2] J F Kreider, P Curtiss, and A Rabl, Heating and cooling of buildings: design for efficiency McGraw-Hill New York, 1994 [3] D Kiel and D Wilson, Gravity driven flows through open doors, in 7th AIVC Conference, 1986 [4] B Nordquist and L Jensen, A dynamic model for single sided ventilation Air Distribution in Rooms: Ventilation for Health and Sustainable Environment, p 211, 2000 [5] G Gan, H Awbi, and D Croome, Simulation of air flow in naturally ventilated buildings, Proceedings of Building Simulation, Nice, France, pp 78 84,

12 Fig 7 MATLAB code 12

SAMPLE ASSESSMENT TASKS PHYSICS ATAR YEAR 11

SAMPLE ASSESSMENT TASKS PHYSICS ATAR YEAR 11 SAMPLE ASSESSMENT TASKS PHYSICS ATAR YEAR Copyright School Curriculum and Standards Authority, 204 This document apart from any third party copyright material contained in it may be freely copied, or communicated

More information

SPH3U1 Lesson 03 Energy

SPH3U1 Lesson 03 Energy THERMAL ENERGY AND LATENT HEAT LEARNING GOALS Students will learn: Heat changes the amount of thermal energy in an object Temperature is a measure of the average thermal energy in an object Heat capacity

More information

Review: Heat, Temperature, Heat Transfer and Specific Heat Capacity

Review: Heat, Temperature, Heat Transfer and Specific Heat Capacity Name: Block: Date: IP 614 Review: Heat, Temperature, Heat Transfer and Specific Heat Capacity All these questions are real MCAS questions! 1. In a copper wire, a temperature increase is the result of which

More information

the distance of conduction (the thickness), the greater the heat flow.

the distance of conduction (the thickness), the greater the heat flow. R-Values In heat conduction, the rate of heat flow depends on the temperature difference between sides, the thickness, and the area in contact. The greater the temperature difference, the greater the heat

More information

Chapter 11. Important to distinguish between them. They are not interchangeable. They mean very different things when used in physics Internal Energy

Chapter 11. Important to distinguish between them. They are not interchangeable. They mean very different things when used in physics Internal Energy Chapter 11 Energy in Thermal Processes Energy Transfer When two objects of different temperatures are placed in thermal contact, the temperature of the warmer decreases and the temperature of the cooler

More information

Experimental Performance and Numerical Simulation of Double Glass Wall Thana Ananacha

Experimental Performance and Numerical Simulation of Double Glass Wall Thana Ananacha Experimental Performance and Numerical Simulation of Double Glass Wall Thana Ananacha Abstract This paper reports the numerical and experimental performances of Double Glass Wall are investigated. Two

More information

Infrared Experiments of Thermal Energy and Heat Transfer

Infrared Experiments of Thermal Energy and Heat Transfer Infrared Experiments of Thermal Energy and Heat Transfer You will explore thermal energy, thermal equilibrium, heat transfer, and latent heat in a series of hands-on activities augmented by the thermal

More information

Prediction of Thermal Comfort and Ventilation Efficiency for Small and Large Enclosures by Combined Simulations

Prediction of Thermal Comfort and Ventilation Efficiency for Small and Large Enclosures by Combined Simulations Institute for Thermodynamics and Building Energy Systems, Dresden University of Technology Prediction of Thermal Comfort and Ventilation Efficiency for Small and Large Enclosures by Combined Simulations

More information

General Physics (PHY 2130)

General Physics (PHY 2130) General Physics (PHY 2130) Lecture 34 Heat Heat transfer Conduction Convection Radiation http://www.physics.wayne.edu/~apetrov/phy2130/ Lightning Review Last lecture: 1. Thermal physics Heat. Specific

More information

Energy in Thermal Processes. Heat and Internal Energy

Energy in Thermal Processes. Heat and Internal Energy Energy in Thermal Processes Heat and Internal Energy Internal energy U: associated with the microscopic components of a system: kinetic and potential energies. The larger the number of internal degrees

More information

K20: Temperature, Heat, and How Heat Moves

K20: Temperature, Heat, and How Heat Moves K20: Temperature, Heat, and How Heat Moves Definition of Temperature Definition of Heat How heat flows (Note: For all discussions here, particle means a particle of mass which moves as a unit. It could

More information

The Kinetic Theory of Matter. Temperature. Temperature. Temperature. Temperature. Chapter 6 HEAT

The Kinetic Theory of Matter. Temperature. Temperature. Temperature. Temperature. Chapter 6 HEAT The Kinetic Theory of Matter Hewitt/Lyons/Suchocki/Yeh Conceptual Integrated Science Chapter 6 HEAT Kinetic Theory of Matter: Matter is made up of tiny particles (atoms or molecules) that are always in

More information

5. Temperature and Heat

5. Temperature and Heat Leaving Cert Physics Long Questions 2017-2002 5. Temperature and Heat Please remember to photocopy 4 pages onto one sheet by going A3 A4 and using back to back on the photocopier Contents Temperature:

More information

Chapter 11 Thermal Transport

Chapter 11 Thermal Transport Chapter 11 Thermal Transport GOALS When you have mastered the contents of this chapter, you will be able to achieve the following goals: Definitions Define the following terms, and use them in an operational

More information

PHYSICS 149: Lecture 26

PHYSICS 149: Lecture 26 PHYSICS 149: Lecture 26 Chapter 14: Heat 14.1 Internal Energy 14.2 Heat 14.3 Heat Capacity and Specific Heat 14.5 Phase Transitions 14.6 Thermal Conduction 14.7 Thermal Convection 14.8 Thermal Radiation

More information

Conduction is the transfer of heat by the direct contact of particles of matter.

Conduction is the transfer of heat by the direct contact of particles of matter. Matter and Energy Chapter 9 energy flows from a material at a higher temperature to a material at a lower temperature. This process is called heat transfer. How is heat transferred from material to material,

More information

Study of air curtains used to restrict infiltration into refrigerated rooms

Study of air curtains used to restrict infiltration into refrigerated rooms Study of air curtains used to restrict infiltration into refrigerated rooms Gregory Verhaeghe 1, Marnix Van Belleghem 1, Arnout Willockx 1, Ivan Verhaert 1, Michel De Paepe 1 1 Ghent University, Department

More information

ADVANCED ROOF COATINGS: MATERIALS AND THEIR APPLICATIONS

ADVANCED ROOF COATINGS: MATERIALS AND THEIR APPLICATIONS ADVANCED ROOF COATINGS: MATERIALS AND THEIR APPLICATIONS Abstract J.M. Bell 1 and G.B. Smith 2 The use of low emittance and high solar reflectance coatings is widespread in window glazings, wall and roof

More information

Academic Year 2016-2017 First Term Science Revision sheets PHYSICS ( Answer key ) Name: Grade: 10 Date: Section: (A) Science Practice : Q1: Choose the letter of the choice that best answer the questions:

More information

Clouds and Rain Unit (3 pts)

Clouds and Rain Unit (3 pts) Name: Section: Clouds and Rain Unit (Topic 8A-2) page 1 Clouds and Rain Unit (3 pts) As air rises, it cools due to the reduction in atmospheric pressure Air mainly consists of oxygen molecules and nitrogen

More information

4.1. Physics Module Form 4 Chapter 4 - Heat GCKL UNDERSTANDING THERMAL EQUILIBRIUM. What is thermal equilibrium?

4.1. Physics Module Form 4 Chapter 4 - Heat GCKL UNDERSTANDING THERMAL EQUILIBRIUM. What is thermal equilibrium? Physics Module Form 4 Chapter 4 - Heat GCKL 2010 4.1 4 UNDERSTANDING THERMAL EQUILIBRIUM What is thermal equilibrium? 1. (, Temperature ) is a form of energy that flows from a hot body to a cold body.

More information

Heat. Conduction. Heat moves in three ways. They are conduction, convection, and radiation.

Heat. Conduction. Heat moves in three ways. They are conduction, convection, and radiation. Heat Heat doesn t stay put. It moves. It gets passed from one thing to another. This idea may sound very simple. There are some big ideas behind it. The study of heat is called thermodynamics (thurmoh-dye-nam-iks).

More information

Building Envelope Requirements Overview Page 3-4

Building Envelope Requirements Overview Page 3-4 Building Envelope Requirements Overview Page 3-4 The benefit of a high reflectance surface is obvious: while dark surfaces absorb the sun s energy (visible light, invisible infrared. and ultraviolet radiation)

More information

Chapter 10 Test Form B

Chapter 10 Test Form B Chapter 10 Test Form A 1. B 2. A 3. A 4. B 5. D 6. B 7. B 8. A 9. A 10. A 11. B 12. D 13. A 14. C 15. No, heat and cold do not flow between objects. Energy transferred between objects changes the temperature

More information

Chapter 11. Energy in Thermal Processes

Chapter 11. Energy in Thermal Processes Chapter 11 Energy in Thermal Processes Vocabulary, 3 Kinds of Energy Internal Energy U = Energy of microscopic motion and intermolucular forces Work W = -F x = -P V is work done by compression (next chapter)

More information

Student Exploration: Energy Conversion in a System

Student Exploration: Energy Conversion in a System Name: Date: Student Exploration: Energy Conversion in a System Vocabulary: energy, gravitational potential energy, heat energy, kinetic energy, law of conservation of energy, specific heat capacity Prior

More information

Radiant Heating Panel Thermal Analysis. Prepared by Tim Fleury Harvard Thermal, Inc. October 7, 2003

Radiant Heating Panel Thermal Analysis. Prepared by Tim Fleury Harvard Thermal, Inc. October 7, 2003 Radiant Heating Panel Thermal Analysis Prepared by Tim Fleury Harvard Thermal, Inc. October 7, 2003 Analysis Objective Perform a thermal test on a small sample of the concrete to determine the Thermal

More information

CHAPTER 14: HEAT AND HEAT TRANSFER METHODS

CHAPTER 14: HEAT AND HEAT TRANSFER METHODS College Physics Student s Manual Chapter CHAPTER : HEAT AND HEAT TRANSFER METHODS. TEMPERATURE CHANGE AND HEAT CAPACITY. On a hot day, the temperature of an 80,000- L swimming pool increases by.0 C. What

More information

HEAT HISTORY. D. Whitehall

HEAT HISTORY. D. Whitehall 1 HEAT HISTORY 18 th Century In the 18 th century it was assumed that there was an invisible substance called caloric. When objects got it was assumed that they gained caloric, therefore hot objects should

More information

Academic Year First Term. Science Revision sheets PHYSICS

Academic Year First Term. Science Revision sheets PHYSICS Academic Year 2016-2017 First Term Science Revision sheets PHYSICS Name: Grade: 10 Date: Section: (A) Science Practice : Q1: Choose the letter of the choice that best answer the questions: 1. What term

More information

Simultaneous Conduction and Radiation Energy Transfer

Simultaneous Conduction and Radiation Energy Transfer Simultaneous Conduction and Radiation Energy Transfer Radiant energy can transfer from a colder to a warmer radiator. ###########, PhD Chemical Process Control Systems Engineer, PE TX & CA Abstract The

More information

!U = Q " P!V. Q = mc!t. Vocabulary, 3 Kinds of Energy. Chapter 11. Energy in Thermal Processes. Example Temperature and Specific Heat

!U = Q  P!V. Q = mc!t. Vocabulary, 3 Kinds of Energy. Chapter 11. Energy in Thermal Processes. Example Temperature and Specific Heat Vocabulary, 3 Kinds of Energy Chapter 11 Energy in Thermal Processes Internal Energy U = Energy of microscopic motion and intermolucular forces Work W = -F!x = -P!V is work done by compression (next chapter)

More information

Living with Thermal Expansion and Contraction

Living with Thermal Expansion and Contraction 7.5 Living with Thermal Expansion and Contraction Key Question: How do thermal expansion and contraction affect everyday objects? Temperatures change all the time. In general, days are warmer than nights.

More information

Introduction to Atmospheric Circulation

Introduction to Atmospheric Circulation Introduction to Atmospheric Circulation Start rotating table Start heated bottle experiment Scientific Practice Observe nature Develop a model*/hypothesis for what is happening Carry out experiments Make

More information

Chapter 3 NATURAL CONVECTION

Chapter 3 NATURAL CONVECTION Fundamentals of Thermal-Fluid Sciences, 3rd Edition Yunus A. Cengel, Robert H. Turner, John M. Cimbala McGraw-Hill, 2008 Chapter 3 NATURAL CONVECTION Mehmet Kanoglu Copyright The McGraw-Hill Companies,

More information

Radiation, Sensible Heat Flux and Evapotranspiration

Radiation, Sensible Heat Flux and Evapotranspiration Radiation, Sensible Heat Flux and Evapotranspiration Climatological and hydrological field work Figure 1: Estimate of the Earth s annual and global mean energy balance. Over the long term, the incoming

More information

A SIMPLE MODEL FOR THE DYNAMIC COMPUTATION OF BUILDING HEATING AND COOLING DEMAND. Kai Sirén AALTO UNIVERSITY

A SIMPLE MODEL FOR THE DYNAMIC COMPUTATION OF BUILDING HEATING AND COOLING DEMAND. Kai Sirén AALTO UNIVERSITY A SIMPLE MODEL FOR THE DYNAMIC COMPUTATION OF BUILDING HEATING AND COOLING DEMAND Kai Sirén AALTO UNIVERSITY September 2016 CONTENT 1. FUNDAMENTALS OF DYNAMIC ENERGY CALCULATIONS... 3 1.1. Introduction...

More information

TEMPERATURE AND DEEP OCEAN CIRCULATION

TEMPERATURE AND DEEP OCEAN CIRCULATION TEMPERATURE AND DEEP OCEAN CIRCULATION OVERVIEW Ocean currents arise in several ways. For example, wind pushes the water along the surface to form wind-driven currents. Over larger areas, circular wind

More information

Exercises Conduction (pages ) 1. Define conduction. 2. What is a conductor?

Exercises Conduction (pages ) 1. Define conduction. 2. What is a conductor? Exercises 22.1 Conduction (pages 431 432) 1. Define conduction. 2. What is a conductor? 3. are the best conductors. 4. In conduction, between particles transfer thermal energy. 5. Is the following sentence

More information

Physics 4C Chapter 18: Temperature, Heat, and the First Law of Thermodynamics

Physics 4C Chapter 18: Temperature, Heat, and the First Law of Thermodynamics Physics 4C Chapter 18: Temperature, Heat, and the First Law of Thermodynamics Anyone who has never made a mistake has never tried anything new. Albert Einstein Experience is the name that everyone gives

More information

PE = mgh. Potential energy. What is g here? Let s pick up where we left off last time..the topic was gravitational potential energy

PE = mgh. Potential energy. What is g here? Let s pick up where we left off last time..the topic was gravitational potential energy Let s pick up where we left off last time..the topic was gravitational potential energy Now, let s talk about a second form of energy Potential energy Imagine you are standing on top of half dome in Yosemite

More information

A) 3.1 m/s B) 9.9 m/s C) 14 m/s D) 17 m/s E) 31 m/s

A) 3.1 m/s B) 9.9 m/s C) 14 m/s D) 17 m/s E) 31 m/s 1. A large tank, open at the top, is filled with water to a depth of 15 m. A spout located 10.0 m above the bottom of the tank is then opened as shown in the drawing. With what speed will water emerge

More information

RELATIONSHIPS BETWEEN OVERALL THERMAL SENSATION, ACCEPTABILITY AND COMFORT

RELATIONSHIPS BETWEEN OVERALL THERMAL SENSATION, ACCEPTABILITY AND COMFORT RELATIONSHIPS BETWEEN OVERALL THERMAL SENSATION, ACCEPTABILITY AND COMFORT Yufeng Zhang 1, and Rongyi Zhao 2 1 State Key Laboratory of Subtropical Building Science, South China University of Technology,

More information

Solar Flat Plate Thermal Collector

Solar Flat Plate Thermal Collector Solar Flat Plate Thermal Collector INTRODUCTION: Solar heater is one of the simplest and basic technologies in the solar energy field. Collector is the heart of any solar heating system. It absorbs and

More information

Chapter 11. Energy in Thermal Processes

Chapter 11. Energy in Thermal Processes Chapter 11 Energy in Thermal Processes Vocabulary, 3 Kinds of Energy Internal Energy U Energy of a system due to microscopic motion and inter-molucular forces Work W -F x -P V is work done by expansion

More information

Massachusetts Institute of Technology Physics Department

Massachusetts Institute of Technology Physics Department Massachusetts Institute of Technology Physics Department Physics 8.21 Fall 2011 Physics of Energy October 4, 2011 Quiz 1 Instructions Problem Points 1 30 2 45 3 25 4 (+ 20) Total 100 You must do problems

More information

A Calibrated Multi-Zone Airflow Model for Extension of Ventilation System Tracer Gas Testing

A Calibrated Multi-Zone Airflow Model for Extension of Ventilation System Tracer Gas Testing building science.com 2009 Building Science Press All rights of reproduction in any form reserved. A Calibrated Multi-Zone Airflow Model for Extension of Ventilation System Tracer Gas Testing Conference

More information

Composition, Structure and Energy. ATS 351 Lecture 2 September 14, 2009

Composition, Structure and Energy. ATS 351 Lecture 2 September 14, 2009 Composition, Structure and Energy ATS 351 Lecture 2 September 14, 2009 Composition of the Atmosphere Atmospheric Properties Temperature Pressure Wind Moisture (i.e. water vapor) Density Temperature A measure

More information

Applications of Systems of Differential Equations

Applications of Systems of Differential Equations Brine Tank Cascade Cascade Model Recycled Brine Tank Cascade Recycled Cascade Model Home Heating Newton Cooling Model Applications of Systems of Differential Equations Homogeneous Solution and Particular

More information

Determination of moisture surface transfer coefficients under transient conditions

Determination of moisture surface transfer coefficients under transient conditions Determination of moisture surface transfer coefficients under transient conditions T. Bednar & J. Dreyer University of Technology Vienna, Vienna, Austria ABSTRACT: Detailed investigations on surface transfer

More information

Sunlight and Temperature

Sunlight and Temperature Sunlight and Temperature Name Purpose: Study microclimate differences due to sunlight exposure, location, and surface; practice environmental measurements; study natural energy flows; compare measurements;

More information

Atoms and molecules are in motion and have energy

Atoms and molecules are in motion and have energy Atoms and molecules are in motion and have energy By now you know that substances are made of atoms and molecules. These atoms and molecules are always in motion and have attractions to each other. When

More information

Mechanical Equivalence of Heat

Mechanical Equivalence of Heat Chapter 2 Mechanical Equivalence of Heat 2.1 Purpose The purpose of this lab is to demonstrate the equivalence between mechanical work and heat. 2.2 Introduction Note: For this experiment, you will write

More information

EXPERIMENT ET: ENERGY TRANSFORMATION & SPECIFIC HEAT

EXPERIMENT ET: ENERGY TRANSFORMATION & SPECIFIC HEAT MASSACHUSETTS INSTITUTE OF TECHNOLOGY Physics Department Physics 8.01X Fall 2000 EXPERIMENT ET: ENERGY TRANSFORMATION & SPECIFIC HEAT We have introduced different types of energy which help us describe

More information

NEW GCSE 4463/01 SCIENCE A FOUNDATION TIER PHYSICS 1

NEW GCSE 4463/01 SCIENCE A FOUNDATION TIER PHYSICS 1 Surname Other Names Centre Number 0 Candidate Number NEW GCSE 4463/01 SCIENCE A FOUNDATION TIER PHYSICS 1 ADDITIONAL MATERIALS In addition to this paper you may require a calculator. INSTRUCTIONS TO CANDIDATES

More information

We call the characteristic of a system that determines how much its temperature will change heat capacity.

We call the characteristic of a system that determines how much its temperature will change heat capacity. 3/3 Measuring Heat If all we do is add heat to a system its temperature will rise. How much the temperature rises depends on the system. We call the characteristic of a system that determines how much

More information

Conceptual Physics Fundamentals

Conceptual Physics Fundamentals Conceptual Physics Fundamentals Chapter 8: TEMPERATURE, HEAT, AND THERMODYNAMICS This lecture will help you understand: Temperature Absolute Zero Internal Energy Heat Quantity of Heat The Laws of Thermodynamics

More information

Transient flow and heat equations - the Rayleigh-Benard instability

Transient flow and heat equations - the Rayleigh-Benard instability Transient flow and heat equations - the Rayleigh-Benard instability Directory: RayleighBenard Solvers: HeatSolve, FlowSolve Tools: ElmerGUI Dimensions: 2D, Transient Case definition This tutorial is about

More information

Unit Two Worksheet Matter and Energy WS PS U2

Unit Two Worksheet Matter and Energy WS PS U2 Unit Two Worksheet Matter and Energy WS PS U2 Name Period Section 4.1 Matching. Match the definition with the term that best correlates to it. 1. Chemical potential energy 2. Elastic potential energy 3.

More information

Chapter 17 Temperature and heat

Chapter 17 Temperature and heat Chapter 17 Temperature and heat 1 Temperature and Thermal Equilibrium When we speak of objects being hot and cold, we need to quantify this by some scientific method that is quantifiable and reproducible.

More information

Thermal Flow Sensor Modeling Using Electronic Circuit Simulator

Thermal Flow Sensor Modeling Using Electronic Circuit Simulator Thermal Flow Sensor Modeling Using Electronic Circuit Simulator 1. Introduction. Alexei Smirnov Sidelinesoft, nl5@sidelinesoft.com Computational fluid dynamics (CFD) modeling becomes more and more popular

More information

National 5 Physics. Electricity and Energy. Notes

National 5 Physics. Electricity and Energy. Notes National 5 Physics Electricity and Energy Notes Name. 1 P a g e Key Area Notes, Examples and Questions Page 3 Conservation of energy Page 10 Electrical charge carriers and electric fields and potential

More information

Bridge Grade Two Winter 1/09 1. GRADE TWO WINTER NATURE WALK Using Thermometers

Bridge Grade Two Winter 1/09 1. GRADE TWO WINTER NATURE WALK Using Thermometers Bridge Grade Two Winter 1/09 1 GRADE TWO WINTER NATURE WALK Using Thermometers OBJECTIVES: Use thermometers to measure temperature. Compare temperature of air and water inside and outside the school. Relate

More information

Physical Science. Thermal Energy & Heat

Physical Science. Thermal Energy & Heat Physical Science Thermal Energy & Heat Sometimes called internal energy Depends on the object's mass, temperature, and phase (solid, liquid, gas) TOTAL potential and kinetic energy of all the particles

More information

BES with FEM: Building Energy Simulation using Finite Element Methods

BES with FEM: Building Energy Simulation using Finite Element Methods BES with FEM: Building Energ Simulation using Finite Element Methods A.W.M. (Jos) van Schijndel Eindhoven Universit of Technolog P.O. Bo 513; 5600 MB Eindhoven; Netherlands, A.W.M.v.Schijndel@tue.nl Abstract:

More information

10-year industry best core warranty. 2-year warranty on balance of unit.

10-year industry best core warranty. 2-year warranty on balance of unit. MODEL FEATURES MERV-8 filters Fully insulated case Large cores for high efficiency No condensate pan or drain required AHRI Certified Rainhood included Access door for easy maintenance and Cleaning Integral

More information

HEAT TRANSFER 1 INTRODUCTION AND BASIC CONCEPTS 5 2 CONDUCTION

HEAT TRANSFER 1 INTRODUCTION AND BASIC CONCEPTS 5 2 CONDUCTION HEAT TRANSFER 1 INTRODUCTION AND BASIC CONCEPTS 5 2 CONDUCTION 11 Fourier s Law of Heat Conduction, General Conduction Equation Based on Cartesian Coordinates, Heat Transfer Through a Wall, Composite Wall

More information

A CFD SIMULATION AND OPTIMIZATION OF SUBWAY STATION VENTILATION

A CFD SIMULATION AND OPTIMIZATION OF SUBWAY STATION VENTILATION A CFD SIMULATION AND OPTIMIZATION OF SUBWAY STATION VENTILATION L Wang 1,4*, G Tu 2,4, T Zou 3,4 and J Yang 4 1 The School of Environmental Science and Engineering, Tianjin University, Tianjin, China 2

More information

TOWARDS A MORE RELIABLE MODELLING OF NIGHT-TIME VENTILATION WITH BUILDING ENERGY SIMULATION MODELS

TOWARDS A MORE RELIABLE MODELLING OF NIGHT-TIME VENTILATION WITH BUILDING ENERGY SIMULATION MODELS TOWARDS A MORE RELIABLE MODELLING OF NIGHT-TIME VENTILATION WITH BUILDING ENERGY SIMULATION MODELS Sarah Leenknegt 1, Rolf Wagemakers 2, Walter Bosschaerts 2, Dirk Saelens 1 1 Building Physics Section,

More information

Relative Humidity and Dew Point Lab

Relative Humidity and Dew Point Lab Name: Relative Humidity and Dew Point Lab Weather is the present state of the atmosphere. Factors that determine the type of weather the world will have are: air pressure, wind, temperature and the air

More information

Computational Modelling of the Impact of Solar Irradiance on Chemical Degradation of Painted Wall Hangings in an Historic Interior

Computational Modelling of the Impact of Solar Irradiance on Chemical Degradation of Painted Wall Hangings in an Historic Interior Computational Modelling of the Impact of Solar Irradiance on Chemical Degradation of Painted Wall Hangings in an Historic Interior Z. Huijbregts *1, A.W.M. van Schijndel 1, H.L. Schellen 1, K. Keune 2,

More information

Experiment 1. Measurement of Thermal Conductivity of a Metal (Brass) Bar

Experiment 1. Measurement of Thermal Conductivity of a Metal (Brass) Bar Experiment 1 Measurement of Thermal Conductivity of a Metal (Brass) Bar Introduction: Thermal conductivity is a measure of the ability of a substance to conduct heat, determined by the rate of heat flow

More information

Temperature and Heat. Two systems of temperature. Temperature conversions. PHY heat - J. Hedberg

Temperature and Heat. Two systems of temperature. Temperature conversions. PHY heat - J. Hedberg Temperature and Heat 1. Two systems of temperature 1. Temperature conversions 2. Real science (one scale to rule them all) 3. Temperature scales 2. Effects of temperature on materials 1. Linear Thermal

More information

BIOS. Weather. 266BC Wireless Wind Chill and Humidex Thermometer. Thermomètre sans fil pour indices de refroidissement éolien et humidex

BIOS. Weather. 266BC Wireless Wind Chill and Humidex Thermometer. Thermomètre sans fil pour indices de refroidissement éolien et humidex Weather BIOS 266BC Wireless Wind Chill and Humidex Thermometer Thermomètre sans fil pour indices de refroidissement éolien et humidex Monitor/Moniteur ite r : 4. 5. 6. A. B. C. D. E. 1. 2. 3. Transmitter/Transmetteur

More information

Aalborg Universitet. Empirical Test Case Specification Larsen, Olena Kalyanova; Heiselberg, Per Kvols. Publication date: 2006

Aalborg Universitet. Empirical Test Case Specification Larsen, Olena Kalyanova; Heiselberg, Per Kvols. Publication date: 2006 Aalborg Universitet Empirical Test Case Specification Larsen, Olena Kalyanova; Heiselberg, Per Kvols Publication date: 2006 Document Version Publisher's PDF, also known as Version of record Link to publication

More information

Heat Transfer There are three mechanisms for the transfer of heat:

Heat Transfer There are three mechanisms for the transfer of heat: Heat Transfer There are three mechanisms for the transfer of heat: Conduction Convection Radiation CONDUCTION is a diffusive process wherein molecules transmit their kinetic energy to other molecules by

More information

3.0 FINITE ELEMENT MODEL

3.0 FINITE ELEMENT MODEL 3.0 FINITE ELEMENT MODEL In Chapter 2, the development of the analytical model established the need to quantify the effect of the thermal exchange with the dome in terms of a single parameter, T d. In

More information

PHYSICS 289 Experiment 3 Fall Heat transfer and the Greenhouse Effect

PHYSICS 289 Experiment 3 Fall Heat transfer and the Greenhouse Effect PHYSICS 289 Experiment 3 Fall 2006 Heat transfer and the Greenhouse Effect Only a short report is required: worksheets, graphs and answers to the questions. Introduction In this experiment we study the

More information

MECHATRONICS II LABORATORY Experiment #4: First-Order Dynamic Response Thermal Systems

MECHATRONICS II LABORATORY Experiment #4: First-Order Dynamic Response Thermal Systems MECHATRONICS II LABORATORY Experiment #4: First-Order Dynamic Response Thermal Systems The simplest dynamic system is a linear first order system. The time response of a first-order system is exponential.

More information

Find this material useful? You can help our team to keep this site up and bring you even more content consider donating via the link on our site.

Find this material useful? You can help our team to keep this site up and bring you even more content consider donating via the link on our site. Find this material useful? You can help our team to keep this site up and bring you even more content consider donating via the link on our site. Still having trouble understanding the material? Check

More information

Name Class Date. What are three kinds of energy transfer? What are conductors and insulators? What makes something a good conductor of heat?

Name Class Date. What are three kinds of energy transfer? What are conductors and insulators? What makes something a good conductor of heat? CHAPTER 14 SECTION Heat and Temperature 2 Energy Transfer KEY IDEAS As you read this section, keep these questions in mind: What are three kinds of energy transfer? What are conductors and insulators?

More information

Physics 1010: The Physics of Everyday Life. TODAY Heat and Thermodynamics Thermometers, temperature scales; conduction, convection, radiation.

Physics 1010: The Physics of Everyday Life. TODAY Heat and Thermodynamics Thermometers, temperature scales; conduction, convection, radiation. Physics 1010: The Physics of Everyday Life TODAY Heat and Thermodynamics Thermometers, temperature scales; conduction, convection, radiation. 1 Today s topics Heat and thermometers Burning - conversion

More information

Rate in Thermal Systems

Rate in Thermal Systems Rate in Thermal Systems Overview Rate in Thermal Systems 1 Fundamental Concepts What is the prime mover in the thermal system? temperature difference ( T) What does rate measure in the thermal system?

More information

What are Numerical Methods? (1/3)

What are Numerical Methods? (1/3) What are Numerical Methods? (1/3) Numerical methods are techniques by which mathematical problems are formulated so that they can be solved by arithmetic and logic operations Because computers excel at

More information

What does temperature have to do with energy? What three temperature scales are commonly used? What makes things feel hot or cold?

What does temperature have to do with energy? What three temperature scales are commonly used? What makes things feel hot or cold? Heat and Temperature Section 1: Temperature What does temperature have to do with energy? What three temperature scales are commonly used? What makes things feel hot or cold? 1 Intro: Discussion A person

More information

Key Concept Heat in Earth s atmosphere is transferred by radiation, conduction, and convection.

Key Concept Heat in Earth s atmosphere is transferred by radiation, conduction, and convection. Section 2 Atmospheric Heating Key Concept Heat in Earth s atmosphere is transferred by radiation, conduction, and convection. What You Will Learn Solar energy travels through space as radiation and passes

More information

P1 Quick Revision Questions. P1 for AQA GCSE examination 2018 onwards

P1 Quick Revision Questions. P1 for AQA GCSE examination 2018 onwards P1 Quick Revision Questions Question 1... of 50 What type of energy is stored in a stretched elastic band? Answer 1... of 50 Elastic potential energy. Question 2... of 50 What type of energy is stored

More information

Experimental Evaluation of Natural Heat Transfer in Façade Integrated Triangular Enclosures

Experimental Evaluation of Natural Heat Transfer in Façade Integrated Triangular Enclosures Peer Reviewed Paper Piratheepan Experimental Evaluation of Natural Heat Transfer in Façade Integrated Triangular Enclosures Abstract M Piratheepan 1, T N Anderson 1, S Saiful 1 1 Auckland University of

More information

Cover Page: Entropy Summary

Cover Page: Entropy Summary Cover Page: Entropy Summary Heat goes where the ratio of heat to absolute temperature can increase. That ratio (Q/T) is used to define a quantity called entropy. The useful application of this idea shows

More information

Preparing for Six Flags Physics Concepts

Preparing for Six Flags Physics Concepts Preparing for Six Flags Physics Concepts uniform means constant, unchanging At a uniform speed, the distance traveled is given by Distance = speed x time At uniform velocity, the displacement is given

More information

Supply air beam. Contact, Overview, Index. Guideline heating and cooling. Plexus. Professor / Professor Plus. Premum / Premax / Solus.

Supply air beam. Contact, Overview, Index. Guideline heating and cooling. Plexus. Professor / Professor Plus. Premum / Premax / Solus. Contact, Overview, Index Guideline heating and cooling Plexus Professor / Professor Plus Premum / Premax / Architect Polaris I & S Plafond Podium Celo Cabinett Capella Carat Fasadium Atrium / Loggia Regula

More information

IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 18, NO. 4, OCTOBER

IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 18, NO. 4, OCTOBER TRANSACTIONS ON POWER DELIVERY, VOL. 18, NO. 4, OCTOBER 2003 1 A New Method for the Calculation of the Hot-Spot Temperature in Power Transformers With ONAN Cooling Zoran Radakovic and Kurt Feser, Fellow,

More information

Introduction to Weather Moisture in the Air Vapor Pressure and Dew Point

Introduction to Weather Moisture in the Air Vapor Pressure and Dew Point Introduction to Weather Moisture in the Air Vapor Pressure and Dew Point No study of weather would be complete without a discussion of precipitation. Here in Seattle it seems like it can rain for days

More information

Winter Thermal Comfort in 19 th Century Traditional Buildings of the Town of Florina, in North-Western Greece

Winter Thermal Comfort in 19 th Century Traditional Buildings of the Town of Florina, in North-Western Greece PLEA2 - The 22 nd Conference on Passive and Low Energy Architecture. Beirut, Lebanon, 13-16 November 2 Winter Thermal Comfort in 19 th Century Traditional Buildings of the Town of Florina, in North-Western

More information

What Is Air Temperature?

What Is Air Temperature? 2.2 Read What Is Air Temperature? In Learning Set 1, you used a thermometer to measure air temperature. But what exactly was the thermometer measuring? What is different about cold air and warm air that

More information

SOLIDWORKS Simulation Time Based Thermal Stress

SOLIDWORKS Simulation Time Based Thermal Stress SOLIDWORKS Simulation Time Based Thermal Stress Overview Given that SOLIDWORKS Simulation is capable of running a transient thermal analysis on models it leads to the question of whether the transient

More information

Bernoulli s Principle. Application: Lift. Bernoulli s Principle. Main Points 3/13/15. Demo: Blowing on a sheet of paper

Bernoulli s Principle. Application: Lift. Bernoulli s Principle. Main Points 3/13/15. Demo: Blowing on a sheet of paper Bernoulli s Principle Demo: Blowing on a sheet of paper Where the speed of a fluid increases, internal pressure in the fluid decreases. Due to continuous flow of a fluid: what goes in must come out! Fluid

More information

LECTURE 16: Friction

LECTURE 16: Friction Lectures Page 1 LECTURE 16: Friction Select LEARNING OBJECTIVES: i. ii. iii. iv. v. vi. vii. viii. ix. x. xi. Identify the direction that friction is acting. Identify which object(s) are creating a force

More information

Build a Model of Global Air Movement

Build a Model of Global Air Movement Name Class Date Inquiry Lab DATASHEET FOR IN-TEXT LAB Build a Model of Global Air Movement Warm air rises and cools, and cold air sinks and warms. This is true whether we are observing the temperature

More information

Section 3.5 Thermal Comfort and Heat Stress

Section 3.5 Thermal Comfort and Heat Stress Section 3.5 Thermal Comfort and Heat Stress Table 3.6 Metabolic rate as a function of physical activity for a 70 kg adult man (abstracted from ASHRAE, 1997). activity metabolic rate (W) metabolic rate

More information