Space Propulsion                                                                            and Power                     ...
2012 AFOSR SPRING REVIEWBRIEF DESCRIPTION OF PORTFOLIO:   Multi-disciplinary (Propulsion, Materials, Plasma and Electro-En...
Coupled Materials and Plasma Processes Far                            From Equilibrium                          Kick-off m...
steady-state powered low-density plasmas             Understand and Model the interactions among the              low pres...
Multiple Scales in low-density,                              steady-state powered plasmas                                 ...
Multiple Scales in low-density, steady-state                  powered plasmas - Computational Tools                       ...
Multiple Scales in low-density,                 Multiple Scales in low-density, steady-state                    powered pl...
Multi-scale Modeling of MaterialsB. Wirth, 2004          DISTRIBUTION A: Approved for public release; distribution is unli...
Example:                    Secondary Electron Emission: Good or Bad?  •According to the Classic Fluid theory of Hobbs and...
Example: Secondary Electron Emission: Good or Bad?          Model should account for Non-Equilibrium Effects !!Kinetic the...
Example: Secondary Electron Emission: Good or Bad?                                                         Particle-In-Cel...
Walls Made From Carbon-Based Materials with             Different Micro and Macro Structures Can Have Very              Di...
2012 AFOSR SPRING REVIEWBRIEF DESCRIPTION OF PORTFOLIO:   Multi-disciplinary (Propulsion, Materials, Plasma and Electro-En...
Novel Energetic Materials                                  Workshop, 23-24 August 2011, Arlington, VA                     ...
High speed OH PLIF reveals that coarse ammonium                perchlorate burns much faster at high pressures•The diffusi...
Nano-scale features affecting meso-scale behavior                                    Example: mechanically activated Alumi...
Ammonia Borane (NH3BH3) as propellant additive,                       20% hydrogen by mass, can significantly increase    ...
2012 AFOSR SPRING REVIEWBRIEF DESCRIPTION OF PORTFOLIO:   Multi-disciplinary (Propulsion, Materials, Plasma and Electro-En...
Nonlinear, multi-scale, multi-physics high                     pressure combustion dynamics                       Workshop...
waves structure in a high pressure toroidal                  cavity with concentrated heat release zones                  ...
The increased mean flow due to the convecting              standing waves causes spinning waves with increasing           ...
SummarySpace Propulsion Portfolio has become a platform for Multi-disciplinaryactivities in all scales:        •Propulsion...
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Birkan - Space Propulsion and Power - Spring Review 2012

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Dr. Mitat Birkan presents an overview of his program - Space Propulsion and Power - at the AFOSR 2012 Spring Review.

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Birkan - Space Propulsion and Power - Spring Review 2012

  1. 1. Space Propulsion and Power 8 March 2012 Mitat A. Birkan Program Manager AFOSR/RSA Integrity  Service  Excellence Air Force Research Laboratory9 March 2012 DISTRIBUTION A: Approved for public release; distribution is unlimited 1
  2. 2. 2012 AFOSR SPRING REVIEWBRIEF DESCRIPTION OF PORTFOLIO: Multi-disciplinary (Propulsion, Materials, Plasma and Electro-Energetic Physics, Chemistry, etc), multi-physics, multi-scale approach to complex space propulsion problemsSUB-AREAS IN PORTFOLIO: •Coupled Materials and Plasma Processes Far From Equilibrium with Sayir, Harrison (RSA), and Luginsland (RSE) •Novel Energetic Materials Multi-agency Coordination Committee: Petris/DTRA, Doherty/DHS, Anthenien/ARO, Bedford/ONR, Spowart, Hawkins/AFRL, Palaszewski, Fletcher, Sayir/NASA, Pagoria/LLNL, Owrutsky/NRL, Birkan, Berman/AFOSR •Nonlinear, multi-scale, multi-physics high pressure combustion dynamics with Fahroo (RSL), Darema (CC), and Li (RSA) DISTRIBUTION A: Approved for public release; distribution is unlimited 2
  3. 3. Coupled Materials and Plasma Processes Far From Equilibrium Kick-off meeting, NASA Glenn RC, 29-30 November 2011 with Sayir, Harrison (RSA), and Luginsland (RSE)steady-state powered low-density plasmas~ 1015 #/cm3 Reverse field configurationPulsed-powered relatively low-density electric thrustersplasmas, ~ 1013-20 #/cm3 relativistic magnetronPlasma/Electrode Interactions in High CurrentDensity Environments (HPM sources) supercapacitor500kV, 10kA, GW-class EM fields, 100ns to 1ms railgunPulsed-powered high-density thermal plasmasPressure ~ 10’s Mpa, Temperature ~ 1-10 eV, Pulse time ~ 1 us – 1 msCharacterize Surface / particle Interactions in Space SatelliteEnvironment to mitigate contamination, charging, contaminationthermal control, undesired optical backgrounds /charging DISTRIBUTION A: Approved for public release; distribution is unlimited 3
  4. 4. steady-state powered low-density plasmas Understand and Model the interactions among the low pressure plasma, material, and energy flow TEAM 1 Nasr M. Ghoniem(UCLA) Dan Goebel (JPL) TEAM 2 Igor D. Kaganovich (Princeton) Mitchell L. R. Walker (Georgia Institute of Technology) Yevgeny Raitses (Princeton) Alex Kieckhafer (Georgia Institute of Technology) Shahram Sharafat (UCLA) Jud Ready (Georgia Tech Research Institute) Brian Williams (Ultramet) Greg Thompson (University of Alabama) Richard Wirz (UCLA) How to model plasma-materialWhat are the relationships between surface interaction to characterize grainarchitecture and secondary electron emission, and detachment, sputtering leadingthe damage energy fluence limits? to plasma modifications ? TEAM 3 Manuel Martinez-Sanchez (MIT) Mark Cappelli (Stanford), Dennis Whyte (MIT-PSFC) What is the the effect of sheath instabilities, gas retention, and plasma-induced structural modifications on global performance ? DISTRIBUTION A: Approved for public release; distribution is unlimited 4
  5. 5. Multiple Scales in low-density, steady-state powered plasmas Thruster Sheath Plume scale scale ms - s Time scale Ionization instabilitiesms - ms Ionization Electron-ion collisions Sheath instability Electron-neutral Beam/Drift-dissipative ion-gyroradiusns - ms collision instabilities Electron-wall Ionization mean collision High-frequency free path instability Electron Grain gyroradius detachment ps - ns Sputtering Plasma sheath Length Secondary thickness scale electron Debye length emission Å - nm nm - mm mm - mm mm - m DISTRIBUTION A: Approved for public release; distribution is unlimited 5
  6. 6. Multiple Scales in low-density, steady-state powered plasmas - Computational Tools Thruster Debye length Plume scale scale ms - s Time scale Spokems - ms instability Breathing Sheath instability Electron-ion instability Drift-dissipative collisions Electron-neutral instability Low hybrid collision ion-gyroradius instabilityns - ms Electron-wall Ionization mean collision High-frequency Non-Maxwellian EEDF instability free path Electron (MCC, BE) Electron cyclotron Grain gyroradius detachment ps - ns Sputtering Plasma sheath Length Quantum Mechanics thickness Secondary Molecular Dynamics scale electron Debye length emission Å - nm nm - mm mm - mm mm - m DISTRIBUTION A: Approved for public release; distribution is unlimited 6
  7. 7. Multiple Scales in low-density, Multiple Scales in low-density, steady-state powered plasmas - Diagnostic Tools stead-state lasmas Thruster Debye length Plume scale scale ms - s Time scale Stark Broadening Spokems - ms Ionization instability Raman Scattering Breathing Sheath instability THz Interferometer Electron-ion instability Drift-dissipative collisions Electron-neutral instability Low hybrid collision ion-gyroradius instabilityns - ms Langmuir probes Electron-wall Ionization mean collision High-frequency Non-Maxwellian EEDF instability free path Electron (MCC, BE) Electron cyclotron Grain gyroradius detachment ps - ns Sputtering Plasma sheath Length Quantum Mechanics thickness Secondary Molecular Dynamics scale electron Debye length emission Å - nm nm - mm mm - mm mm - m DISTRIBUTION A: Approved for public release; distribution is unlimited 7
  8. 8. Multi-scale Modeling of MaterialsB. Wirth, 2004 DISTRIBUTION A: Approved for public release; distribution is unlimited 8
  9. 9. Example: Secondary Electron Emission: Good or Bad? •According to the Classic Fluid theory of Hobbs and Wesson, SEE is GOOD !!, leads to reduced wall erosion !! Martinez – Sanchez / MIT (1997) •Fluid theory assumes isotropic equilibrium (Maxwellian), Sheath and for walls with very high secondary electron see Bulk Plasma r emission, sheath collapses, sheath potential negligible !! E=0 q 0 electron velocity V distribution function Wall Ion e - Ion e - e - Ion Ion Ion e - 120 e - Ion e - e - Maximum electron temperature, eV Ion Low SEE segmented Ion Ion 90 Ion e - E0 Ve e Ion 60 High SEE BN channelOne Problem: can not 30predict the experimental fluid theory for high SEEresults 0 100 200 300 400 500 600 700 800 •WHY? Discharge voltage, V •Plasma mean free path in thrusters are too high to achieve equilibrium (not enough electron-electron collisions) •According to the fluid theory, maximum electron temperature does not change with discharge power due to huge electron heat flux to the wall DISTRIBUTION A: Approved for public release; distribution is unlimited 9
  10. 10. Example: Secondary Electron Emission: Good or Bad? Model should account for Non-Equilibrium Effects !!Kinetic theory of Meezan and Cappelli / Stanford, High Secondary Electron EmissionDepletes Tail of the Isotropic Electron Velocity Distribution •Solution of the Boltzmann Equation , ISOTROPIC electron velocity Wall potential distribution function (non-Maxwellian) Wall potential (Maxwellian) •High Energy Electrons lost at wall •Isotropic, can not predict secondary electron emission beams, and sheath instabilities•Sheath does not collapse, so Secondary Electron Emission has little effect on EROSION! DISTRIBUTION A: Approved for public release; distribution is unlimited 10
  11. 11. Example: Secondary Electron Emission: Good or Bad? Particle-In-Cell (PIC) simulations suggests that the electron velocity distribution function is Anisotropic !! •Correctly predicts secondary electron emission beams, and sheath instabilities (Raitses, Kaganovich / Princeton) sharp peaks are due electron velocity to the Secondary distribution Electron Beams 120 functionMaximum electron temperature, eV Low SEE segmented 90 60 kinetic theory High SEE BN channel 30 fluid theory for high SEE 0 100 200 300 400 500 600 700 800 Discharge voltage, V •Secondary electron emission does not change the sheath potential •Secondary electron beams cause instabilities near the sheath surface due to the “BUNCH UP” DISTRIBUTION A: Approved for public release; distribution is unlimited 11
  12. 12. Walls Made From Carbon-Based Materials with Different Micro and Macro Structures Can Have Very Different Effect On Plasma and Sheath InstabilitiesDiamond Wall BHT-200 – Cappelli / Stanford (Secondary Electron Emission is unknown) Diamond Outer •Fundamental experiments verified high sputter resistance Channel (GOOD!) •Diamond (carbon) walls exaggerated plasma fluctuations – plasma very UNSTABLE leading to VERY LOW THRUSTER EFFICIENCIES !!! Diamond NoseconeCarbon Velvet Wall– Raitses, Fisch, Kaganovich (Princeton) (has ZERO Secondary Electron Emission) •Carbon velvet acts as almost ideal “black body” absorbing all incident particles preventing SEE •With non-emitting carbon velvet walls, thruster operates more stable (no SEE induced instabilities of the plasma-sheath, attenuated breathing oscillations) •With carbon velvet walls, the maximum electric field can be 2-3 times larger than with ceramic walls •Same element, different structure and architecture different result! •Hypothesis: surface architecture affects performance! DISTRIBUTION A: Approved for public release; distribution is unlimited 12
  13. 13. 2012 AFOSR SPRING REVIEWBRIEF DESCRIPTION OF PORTFOLIO: Multi-disciplinary (Propulsion, Materials, Plasma and Electro-Energetic Physics, Chemistry, etc), multi-physics, multi-scale approach to complex space propulsion problemsSUB-AREAS IN PORTFOLIO: •Coupled Materials and Plasma Processes Far From Equilibrium with Sayir, Harrison (RSA), and Luginsland (RSE) •Novel Energetic Materials Multi-agency Coordination Committee: Petris/DTRA, Doherty/DHS, Anthenien/ARO, Bedford/ONR, Spowart, Hawkins/AFRL, Palaszewski, Fletcher, Sayir/NASA, Pagoria/LLNL, Owrutsky/NRL, Birkan, Berman/AFOSR •Nonlinear, multi-scale, multi-physics high pressure combustion dynamics with Fahroo (RSL), Darema (CC), and Li (RSA) DISTRIBUTION A: Approved for public release; distribution is unlimited 13
  14. 14. Novel Energetic Materials Workshop, 23-24 August 2011, Arlington, VA Next StepThe Sciences graphene sheets decorated with energetic organics andDiscovery, understand, model, and exploit metallic nanoparticles for novel energetics materials to obtain: performance enhancement • Smart Responsive Materials • Nanoenergetics encapsulated nanoscale fuels • Energetic Liquids, Oxidizers, and /catalysts, nanoporous fuel / oxidizer composites for control Binders nPtthrough Multiscale approach from surface functionalization , on graphene particle morphology, andthe atomistic to macroscale Ordered arrays of nano-porous silicone defect reduction to decrease composites sensitivity Current S&T Effort RDX with nano-Al encapsulated Potential Impacts Frozen Propellants •Mission tailored performance, Nickel Aluminum and burning rate, switchable, Metal hydrides smaller platformsState-of-the-Art Polystyrene coating Ammonium Borane • Enhanced and new interactions with external stimuli for total control ofHydrogen and reactionhydrocarbon, • Reduced sensitivity, increased safety,Ionic Propellants and better mobilityADN, HMX • Enabled new missions DISTRIBUTION A: Approved for public release; distribution is unlimited 14
  15. 15. High speed OH PLIF reveals that coarse ammonium perchlorate burns much faster at high pressures•The diffusion flame structure changes from a jet-like to a lifted sheet-like diffusion flame as pressure is increasedbecause of the relatively high local burning rate of the coarse AP (Son / Purdue) 1 atm: Fluorescing coarse AP crystal is shown in red. Dashed line is the surface State-of-the-Art 3-D simulation at high pressure (6 atm) 6 Atm: The relatively fast burning crystal cannot be seen because it is below the surface. •High speed OH PLIF also reveals that: Coarse AP is not affected by catalyst (Fe2O3 and CuO) addition, Catalyst should be inside coarse AP in order to have a greater affect on performance DISTRIBUTION A: Approved for public release; distribution is unlimited 15
  16. 16. Nano-scale features affecting meso-scale behavior Example: mechanically activated Aluminum + Fluorocarbon mixture SEM/EDX (Scanning Electron DSC analysis of Al + polycarbon Microscopy/Energy DIspersive X-ray Al + polycarbon monofluoride monofluoride 158 Spectroscopy) Powder Mixture Activated energetic particlesspeed mode of reaction is not selectable duringal. Aluminum=blue, Fluorine=red Carbon=green Mechanical Activation mechanical activation Figure 7.9. Cartoon comparing scales of mixing for nanometric powders (A for MA 5 micron (B). samplesring scales of mixing for nanometric powders (A) and No mechanical activation Uniform composition and induced for MA samples (B). lattice defects (stored energy)of Ni and Al due to shear is also considered to be of shown in tests using nanometric mixtures of Ni and The extent of mixing of Ni and Al due to shear is also considered totion initiates above and below the rounded plunger ty than it initiates at the center axis of the plunger re shear strain of the bulk material will be highest extreme importance.encapsulated inside aluminum at nanoscales can provide • Fluorinated graphite It was shown in tests using nanometric mixtures of Ns of the plunger. . It is known that shear stress is Al increased combustion efficiency, reduced ignition temperaturebelow the rounded plun that the fast mode of reaction initiates above and and agglomeration Eq. 7.1148 Son / Purdue DISTRIBUTION A: Approved for public release; distribution is unlimited 16
  17. 17. Ammonia Borane (NH3BH3) as propellant additive, 20% hydrogen by mass, can significantly increase rocket performance (Yetter / Penn State) H H B N • Ammonia Borane added to hybrid fuel (paraffin),H Isp,exp increased ~10% with 20% mass addition HH H • Problem: Significant AB addition led to condensed phase product accumulation on fuel grain •MD simulations, kinetic calculations, and TGA/DSC and Confined Rapid Thermolysis/FTIR/MS experiments hydrogen eliminations oxidation NH3BH3 Ea = 27 kcal/mol Ea = 81 kcal/mol (BN)x(H)4x H2NBH2 + H2 HNBH + H2 H2O, H2, HOBO, N2 poly amino borane + O2, OH, O (BN)x(H)2x w/o O2 (or poor mixing) poly imino borane and /or low heating rates Gas phase polymerization Condensed (BN)x(H)4x, (BN)x(H)2x phase polymerization •Hypothesis: Smaller ammonia borane particles may resolve the problem DISTRIBUTION A: Approved for public release; distribution is unlimited 17
  18. 18. 2012 AFOSR SPRING REVIEWBRIEF DESCRIPTION OF PORTFOLIO: Multi-disciplinary (Propulsion, Materials, Plasma and Electro-Energetic Physics, Chemistry, etc), multi-physics, multi-scale approach to complex space propulsion problemsSUB-AREAS IN PORTFOLIO: •Coupled Materials and Plasma Processes Far From Equilibrium with Sayir, Harrison (RSA), and Luginsland (RSE) •Novel Energetic Materials Multi-agency Coordination Committee: Petris/DTRA, Doherty/DHS, Anthenien/ARO, Bedford/ONR, Spowart, Hawkins/AFRL, Palaszewski, Fletcher, Sayir/NASA, Pagoria/LLNL, Owrutsky/NRL, Birkan, Berman/AFOSR •Nonlinear, multi-scale, multi-physics high pressure combustion dynamics with Fahroo (RSL), Darema (CC), and Li (RSA) DISTRIBUTION A: Approved for public release; distribution is unlimited 18
  19. 19. Nonlinear, multi-scale, multi-physics high pressure combustion dynamics Workshop, 15 June 2011, London; Workshop, 23 August 2011, Arlington, VA PARADIGM SHIFT IN SIMULATION: •Reduced Basis and Stochastic Modeling of a Complex High Pressure Combustion System to identify physical mechanisms responsible for the observed dynamical behavior PARADIGM SHIFT IN VALIDATION:Closed-loop actively controlled real-time hybrid approach Experimental domain Boundary conditions=f(r,t) Measured Pressure oscillation CONTROLLER p’(t) Computational domain=“Remainder” of engine DISTRIBUTION A: Approved for public release; distribution is unlimited 19
  20. 20. waves structure in a high pressure toroidal cavity with concentrated heat release zones Zinn, Yang, Neumeier /Georgia Tech, and Law (Princeton)•Consider a toroidal cavity with a single combustion point source. The acoustics is governed by thehomogeneous wave equation except in the singular point. f1 q f2 u- u+ x g2 g1 •Consider now the homogenous wave equation: P 2 / t 2  C 2P 2 / x2 = 0 f ( R ) = x  ct R Right propagating characteristics Right going pressure wave p = f ( ) R R u = R c g ( L ) = x  ct L Left propagating characteristics Left going pressure wave p = g ( ) L L u = L c •With combustion: g1 = g 2    1  q 2c  A The compact heat release source modifies the out going waves f 2 = f1    1  q 2c  A DISTRIBUTION A: Approved for public release; distribution is unlimited 20
  21. 21. The increased mean flow due to the convecting standing waves causes spinning waves with increasing amplitude leading to instability Initial conditions If no tangential mean flow: spinning to a standing wave Initial conditions Right travelling wave f Left travelling wave gTANGENTIAL MEAN FLOW due to recirculation near the injectors and inhomogeneous distribution of heat release, leading Initial conditions to convecting to a spinning wave Initial conditions Right travelling wave f Left travelling wave g •Explained experimental results obtained at NASA (Marcus Heidmann , 1969)Zinn, Yang, Neumeier /Georgia Tech DISTRIBUTION A: Approved for public release; distribution is unlimited 21
  22. 22. SummarySpace Propulsion Portfolio has become a platform for Multi-disciplinaryactivities in all scales: •Propulsion •Materials •Interface Sciences •Plasma and Electro-Energetic Physics •Applied and Computational Mathematics •Chemistry •and others…Will provide the scientific foundation to: •Reduce Fuel Demand in Space / more efficient power generation and energy utilization, increase spacecraft lifetime, and reduce / control waste heat / provide novel design propellants / increase reliability and performance •understand and manage High Energy Density •Enable high-energy storage in ultra-capacitors with nanostructured components, •and others… DISTRIBUTION A: Approved for public release; distribution is unlimited 22

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