and Novel Aerospace Applications of Plasma Assisted Combustion The Ohio State University Nov 4, 2009

Size: px

Start display at page:

Download "and Novel Aerospace Applications of Plasma Assisted Combustion The Ohio State University Nov 4, 2009"

Dina James
5 years ago
Views:

1 Fundamental Mechanisms, Predictive Modeling, and Novel Aerospace Applications of Plasma Assisted Combustion AFOSR MURI Kick off meeting The Ohio State University Nov 4, 2009 Miles Shneider Group

2 Report Documentation Page Form Approved OMB No Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 04 NOV REPORT TYPE 3. DATES COVERED to TITLE AND SUBTITLE Fundamental Mechanisms, Predictive Modeling, and Novel Aerospace Applications of Plasma Assisted Combustion (Princeton) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Princeton University,Princeton,NJ, PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR S ACRONYM(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES U.S. Government or Federal Rights License 14. ABSTRACT 11. SPONSOR/MONITOR S REPORT NUMBER(S) 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE unclassified Same as Report (SAR) 18. NUMBER OF PAGES 36 19a. NAME OF RESPONSIBLE PERSON Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18

3 Personnel Team Richard Miles (PI) Mikhail Shneider (Co PI) Arthur Dogariu (Research Scientist) Sohail Zaidi (Research Scientist) t) Chairajeev Kalra (Student- Princeton Plasma Science and Technology Fellow) James Michael (Student - NDSEG Fellow) Dimitry Opaits (Student) Phil Howard (Technical Support) International Collaborators Sergey Leonov Christophe Laux Svetlana Starikovskaya Boris Potapkin Nickolay Aleksandrov, (Peter Barker)

4 Miles Shneider Group Primary Foci Thrust 1. Experimental studies of nonequilibrium air-fuel plasma kinetics using advanced non-intrusive diagnostics Task 2: Laminar Flow Reactor and Nanoparticle Studies at Low to Intermediate Temperatures (Radar REMPI and Filtered Rayleigh Scattering in flames) Task 7: Fundamental studies on microwave enhanced combustion at atmospheric and higher pressures (Laser designated microwave driven ignition and microwave enhanced flame propagation) Thrust 3. Experimental and modeling studies of fundamental nonequilibrium discharge processes Task 10: Characterization and Modeling of Nsec Pulsed Plasma Discharges (Modeling and Radar REMPI of nonequilibrium states) Task 11: Experimental and Modeling Study of Plasma properties using Radar REMPI (Radar REMPI measurement of electron loss mechanism and rates and local lelectron number density)

5 Preliminary Work Radar REMPI Atomic oxygen in a flame NO mole fractions in laboratory air to <10 ppb Limited by natural NO concentration in NJ air (~10 ppb) Electron attachment and recombination rate measurements in nitrogen, air and humid air Laser designated microwave driven ignition Point ignition with 180 μj, 200 fsec laser designator plus 50 mj, 2 μsec microwave pulse Line ignition with 600 μj, 200 fsec laser designator plus 50 mj, 2 μsec microwave pulse > 50% ignition kernel growth rate enhancement with triple pulsed microwave cowave Multiple point ignition

6 Radar REMPI Microwave scattering from laser-induced carriers Microwave illuminates the ionization spot. Microwave scattering is collected. Laser Microwave Beam Microwave Echo Microwave/laser measurement configuration. The focused laser creates a small region of ionization and the microwaves are scattered from that region into the microwave detector.

Microwave Experimental Setup: Homodyne and Heterodyne 100 GHz

10 GHz mixers Laser Homodyne 100 GHz system.

100 GHz probes the plasma, the phase shift is measured on the 10

The mixer output is proportional with the scattering amplitude,

7 Microwave Experimental Setup: Homodyne and Heterodyne 100 GHz circulator 100 GHz horn 90 GHz pre-amp 10 GHz X Y Quadrature mixer 10 GHz mixers Laser Homodyne 100 GHz system. Heterodyne 100 and 90 GHz system. 100 GHz probes the plasma. 100 GHz probes the plasma, the phase shift is measured on the 10 GHz beating signal. The mixer output is proportional with the scattering amplitude, hence electron density The quadrature mixer provides the X and Y components, hence we also measure the phase. Sub-nanosecond temporal resolution!

8 Atomic oxygen in a flame K Methane Air flame Atomic line of oxygen in flame is narrow (34 cm -1 limited by laser bandwidth) Spectral line in cold air atomic oxygen via photolysis is 10 times broader: high temperature (50,000K) imposed by intense laser pulse. Radar REMPI can distinguish between flame and photolysis atomic oxygen Gaussian fit, = 33.5 cm -1 HW1/e 2 Cold air After subtraction of cold air signal Gaussian fit, = 3.5 cm -1 HW1/e 2 Flame, atomic oxygen line Energy (cm -1 )

9 Resonant signal from atomic oxygen vs. equivalence ratio Atomic Oxygen Atomic oxygen line signal Atomic Oxygen REMPI signal Calculated O mole fraction Rem mpi signal Equivalence ratio Equilibrium model 1D chemkin

10 1+1 Radar REMPI in NO 1+1 Radar REMPI in NO 1+1 REMPI in NO, laser at 226nm Torr NO (80Torr N 2 ) 1 Torr NO (4 Torr N 2 ) signal from NO 1.0 pure NO (50 mtorr) NO (50 mtorr) and N 2 (850 Torr) NO (50 mtorr) and dry air (850 mtorr) Signal Normaliz zed Radar REMPI Energy (cm -1 ) Time (ns) Pure NO shows longer lifetime due to electron diffusion. In order to measure the recombination rate we suppress diffusion by adding N 2. In air we can measure attachment rate.

11 NO trace Detection (limited by background ~ 10 ppb NO in air) air 1ppb 10ppb 100ppb Time (ns)

12 Direct measurement of electron attachment in atmospheric air Previous Extrapolated estimate for 850 Torr dry air (78%N 2, 21%O 2, 1% Ar):

13 Identifying Electron loss mechanism and rate NO at 0.13 Torr in 1atm. buffer (170ppm) NO at 0.13 Torr in 1atm. buffer (170ppm) Norm malized Signal In N 2 : N( t) Air buffer, dn/dt = - n 2 - n = 9.4x10 7 s -1 0 N 2 buffer, dn/dt = - n 2 n 0 = 14x10 7 s -1 1 N0t Time (ns) Norm malized Signal Time (ns) N recombination only, NOT an exponential decay Attachment in air: at N e N( t) N0 at 1 1 e a N0 at N( t) e N0 1 close to close to exponential a 0,

14 Testing NO in buffer gases Signal Radar REMPI in NO at 226 nm 0.15 NO 0.5Torr + N 2 2Torr NO 0.5Torr + N 2 2Torr + dry air 100Torr NO 0.5Torr + N 2 2Torr + dry air 340Torr 0.10 NO 0.5Torr + N 2 2Torr + dry air 760Torr N 2 increases electron loss via recombination by suppressing diffusion Dry air faster decay due to electron Signal NO 0.5Torr + N 2Torr 2 NO 0.5Torr + N 2 2Torr + humid air 97Torr NO 0.5Torr + N 2 2Torr + humid air 752Torr attachment to O 2 Humid air further increase of losses due to higher attachment rates in water Time (ns)

15 Laser Designated Microwave Ignition Experimental Apparatus Camera Screen Magnetron Tuner (d) Waveguide Sliding Short Seed Ionization Laser Pulse Circulator Collimated Nd:YAG (532 nm) Microwave Field 3GHz 30kW peak power TE10 Mode λ guide = 11.2 cm E field ~ 0.1E breakdown Laminar Premixed Flow D premixed = 1.9 cm U exit = 70 cm/s 14

16 Ps Laser-MW Evolution in Air Laser spot evolution Laser + MW evolution MW on

17 Laser Ignition: Kernel growth comparison Single and multiple pulse microwave 0.0 ms 1.0ms 1.1 ms 1.9 ms 2.0ms 2.1 ms 2.9 ms Single pulse 6 mm IGNITION Micro- wave PULSE 1 Microwave PULSE 1 PULSE 2 triple pulse 1 msec intervals PULSE 3 6 mm

18 Multi-point Multi point ignition 6 mm uexit 70 cm/s Two 7mJ seed laser spots 75 mj MW pulse φ = 0.7; Uexit = 70 cm/s 3 ms after initial seed laser pulse Flame kernel indicates ignition

19 200 Femtosecond Seed 180 μj 10 us 100 us 500 us 1000 us 6 mm

20 200 Femtosecond Seed 600 μj 10 us 100 us 500 us 1000 us 6 mm

λ seed [nm] φ f [m] E laser [mj] *E MW [mj]* 800 (200 fs) 0.8 0.06 0.

21 Ignition of Methane/Air Mixtures Seed ionization pulse 7mJ; 200 ps, 780 nm MW heating pulse 50mJ; 2 μs, 3GHz Observed Minimum Seed Laser Energies λ seed [nm] φ f [m] E laser [mj] *E MW [mj]* 800 (200 fs) ,

22 Fundamental Mechanisms, Predictive Modeling, and dnovel laerospace Applications of Plasma Assisted Combustion Team members: Collaborators: Yiguang Ju AFOSR MURI Kick off meeting The Ohio State University Nov 4, 2009 Wenting Sun, Sanghee Won, Mruthunjaya Uddi Interactional: Fei Qi, University of Science and Tech. China AFRL collaborators: Campbell Carter, Timothy Ombrello, Skip Williams

23 Ju s Group Primary Research Focus Thrust 1. The effects of kinetic and transport of plasma assisted ignition Task 1: Experimental measurements of minimum ignition energies using a spherical bomb with different electrode geometries Task 2: Experimental measurements of ignition/extinction limits by using counterflow flames Thrust 2. Intermediate Species Measurements at Elevated Pressures by Using a Plasma Assisted Jet Stirred Reactor with Molecular Beam Sampling Task 1: Development of plasma assisted a jet stirred reactor Task 2: Measurements of intermediate species of fuel oxidation Thrust 3. Mechanism Reduction and Dynamic Multi-time Scale Modeling of Detailed Plasma-Flame Chemistry Task 1: Development of dynamic multi-timescale modeling Task 2: Simulations of unsteady ignition and extinction of plasma discharge with detailed kinetic mechanisms

24 Research Task Description, Methods, and Preliminary Results

spherical bomb with different electrode geometries

5 2.4 2.3 2.2 1.9 Le = 2.1 1.8 = Le 2.0 1.9 1.7 1.

25 Thrust 1. The effects of kinetic and transport of plasma assisted ignition Task 1: Experimental measurements of minimum ignition energies using a spherical bomb with different electrode geometries Q? Q min Minim mun ignitio on power, Q Le = = Le Z= Z= Cube of critical flame radius, R C 2.0

26 Experimental methods (a) (b) (c) (a) (b) (c) Igniter configurations

27 Thrust 1. The effects of kinetic and transport of plasma assisted ignition Task 2: Experimental measurements of ignition/extinction limits by using counterflow flame w/wo non-equilibrium plasma discharge Plasma+CH4/air 1800 x, K Tmax Thermal ignitioniti Kinetic ignition 850 K 900 K 1100 K 1050 K 1025 K 950 K 1000 K 1400 K 1300 K 1200 K Strain, s -1

28 Thrust 1. The effects of kinetic and transport of plasma assisted ignition Task 2: Experimental measurements of ignition/extinction limits by using counterflow flame w/wo non-equilibrium plasma discharge LIF: OH, NO, CH2O TALIF: O, H Nanosecond pulser: Carter

29 Thrust 2: High pressure JSR and MBMS experimental methods of intermediate species measurements High pressure, high temperature chamber Laser beam Preheated air Fuel MBMS analysis Mixing DBD discharge Jet stirred reactor Reactor exit Reaction products Quartz nozzle atm nd 1 st 2 Turbo Turbo pump pump Mass analyzer Skimmer 10-4 Torr Molecular beam Charged ion separation 10-6 Torr

30 Three stage molecular beaming sample for high pressure

31 Equipment installation (EFRC program) Comstock Time of flight (TOF) MB system: RTOF210: Mass resolution up to 5000 m/z Li and Qi, ACR, 2009

32 Thrust 3. Mechanism Reduction and Dynamic Multi-time Scale Modeling of Detailed Plasma-Flame Chemistry Task 1: Development of dynamic multi-timescale modeling approach Task 2: Simulations of unsteady ignition and extinction of plasma discharge with detailed kinetic mechanisms Total computation time K 3 t 80% t Chem t total C. K. Law and T. Lu, Energy and Combustion,2009

33 Multi Time Scale Method (MTS) The Basic Idea of Multi-Time Scale Method: timescale changes! Y k K k e t k Fastest Group Medial Groups Δt F Δt M Number of spe ecies t = 0.1 ms t = 0.2 ms t = 0.3 ms 5 Slowest Group 0 Δt S Log 10 (characteristic time / s) Δt Time Diagram of multi time scale scheme Δt F is the time step of fthe fastest t group, Δt M is the time step of fthe medial group, and Δt S is the time step of the slowest group

34 n-decane/air Validation by homogeneous ignition 121 species (M. Chaos, IJCK,2007) Ignition in homogeneous mixture Mass s fraction 2.8 temperature 10 5 CO OH ODE MTS HMTS C10H Time (0.1 ms) Tempera ature (1000K K) delay time (ms) Ignition 2.0 VODE 1.5 MTS HMTS 1atm atm /Initial temperature (1/K) Temperature and species profiles Ignition delay time for n-decane-air

35 Computation efficiency vs. Mechanism size Base No. Mechanism Time Step(s) Initial Pressure (atm) Initial CPU Time(s) CPU Temperature RTOL ATOL VODE MTS Time (K) Saving a1 H 2 1.0E E-4 1.0E % a2 H 2 1.0E E-4 1.0E % a3 H 2 1.0E E-4 1.0E % a4 H 2 1.0E E-4 1.0E % b1 CH 4 1.0E E-4 1.0E % 7% b2 CH 4 1.0E E-4 1.0E % b3 CH 4 1.0E E-4 1.0E % c1 C 10 H E E-4 1.0E % c2 C 10 H E E-4 1.0E % c3 C 10 H E E-4 1.0E %

36 A path flux analysis method for model reduction T 0 =1200 K ig (s) 0.01 detail DRG PFA 1E-3 1 atm ig (s) 1E-3 1E-4 20 atm Number of species in skeletal lmechnism 15

37 Modeling of flame front trajectories of spherical propagating flames using MTS p p p g g g

Fundamental Mechanisms, Predictive Modeling, and Novel Aerospace Applications of Plasma Assisted Combustion

Fundamental Mechanisms, Predictive Modeling, and Novel Aerospace Applications of Plasma Assisted Combustion Yiguang Ju AFOSR MURI Review Meeting Ohio State University Nov 9-1, 211 Princeton Team members: