1 / 40

NON-EQUILIBRIUM KINETICS IN HIGH ENTHALPY NOZZLE FLOWS

throat. reservoir. exit. NON-EQUILIBRIUM KINETICS IN HIGH ENTHALPY NOZZLE FLOWS. G. Colonna Dip. di Chimica, Universitá di Bari andCNR-IMIP, Bari section. OVERVIEW. NOZZLE FLOW. - Numerical aspects - Coupling with kinetics. NONEQUILIBRIUM KINETICS. - Chemical kinetics

tatiana-fitzgerald
Download Presentation

NON-EQUILIBRIUM KINETICS IN HIGH ENTHALPY NOZZLE FLOWS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. throat reservoir exit NON-EQUILIBRIUM KINETICS IN HIGH ENTHALPY NOZZLE FLOWS G. Colonna Dip. di Chimica, Universitá di Bari andCNR-IMIP, Bari section

  2. OVERVIEW NOZZLE FLOW - Numerical aspects - Coupling with kinetics NONEQUILIBRIUM KINETICS - Chemical kinetics - Vibrational kinetics - Metastable state kinetics coupling state-to-state kinetics with fluid dynamic models FREE ELECTRON KINETICS - Boltzmann equation - Coupling with chemical kinetics - EM fields contribution

  3. ? Mass continuity Energy continuity State equation Momentum continuity quasi one dimensional steady model (space marching) Euler Equations

  4. Multitemperature State-to-state Translational + degrees of freedom in equilibrium Chemical State-to-state kinetics: Multitemperature kinetics: u for internal enthalpy Enthalpy Closure

  5. general reaction source term detailed balance Internal & Chemical Kinetics

  6. detailed balance not valid for global rates general reaction Global rate 2nd Order Rates

  7. Kinetic solution < 0 0 ! Numerical problems 0 NUMERICAL METHODS Sonic point: num=den=0

  8. Speed calculation Kinetic solution Transonic Condition ∆2=0  u=speed of sound NUMERICAL METHODS

  9. N2 Vibrational Relaxation N2(v)+N2(w) <-> N2(v-1)+N2(w+1) N2(v)+N2<->N2(v-1)+N2 N2(v)+N <-> N2(w)+N dissociation Dissociation/Recombination Harmonic obscillator N2(v)+N2(v') <-> N2(v-1)+2N N2(v')+N2<->2N+N2 N2(v)+N <-> 3N v=2 v=1 v=0 N2 Vibrational Kinetics

  10. RECOMBINATION DISSOCIATION N2 Vibrational Distributions (0D) Natoms > Natoms(eq) Tvib > Tgas (similar to nozzle flow) Natoms < Natoms(eq) Tvib < Tgas (similar to shock wave)

  11. N2 Vibrational Relaxation N2* diss/Ric N2* Quenching N2(v)+N2(w) <-> N2(v-1)+N2(w+1) N2(v)+N2<->N2(v-1)+N2 N2(v)+N <-> N2(w)+N N+N+N2<-> N2(B)+N2 N+N+N <-> N2(B)+N N+N+N2<-> N2(A)+N2 N+N+N <-> N2(A)+N N2(A) +N2(A) <-> N2(B)+N2(8) N2(A)+N2(A) <-> N2(C)+N2(2) N2(A)+N2(v≥6) <-> N2(B)+N2(v-6) N2(A) + N2<-> N2(v=0)+N2 N2(A)+N <-> N2(v<10)+N N2(B) + N2<-> N2(0)+N2 N2(a) +N2<-> N2(B)+N2 N2(a) +N <-> N2(B)+N N2(C) +N2<-> N2(a)+N2 Ionization Dissociation/Recombination N* Kinetics N2++N <-> N2(0)+N+ N+ N <-> N2++e- N++ e -<-> N+hn N2(a)+N2(A) <-> N2(v=0)+N2++e- N2(a)+N2(a) <-> N2(0)+N2++e- N2(a)+N2(v>24) <-> N2(0)+N2++e- N2(v)+N2(v') <-> N2(v-1)+2N N2(v')+N2<->2N+N2 N2(v)+N <-> 3N N(2D,2P)+N2<->N(4S)+N2 N(2P)+N(4S) <-> N(2D)+N(4S) N(4P) -> N(4S)+h N2* Radiation N2(B) -> N2(A)+h N2(C) -> N2(B)+h N2 Elementary Processes

  12. O2 Vibrational Relaxation O2* Diss/Ric O2* Kinetics N2* Kinetics O2(v)+O2(w) <-> O2(v-1)+O2(w+1) O2(v)+O2<->O2(v-1)+O2 O2(v)+O <-> O2(v-1)+O O+O+X<-> O2(a)+X O+O+X <-> O2(b)+X N2* + X <-> N2(v=0) + X N2* + X(ground) <-> N2(v=0) + X* N2* + O <-> NO + N* O2* + X <-> O2(v=0) + X O2* + X(ground) <-> N2(v=0) + X* O2* + N <-> NO + O Mixed Vibrational Relaxation Dissociation/Recombination O* Kinetics N* Kinetics O2(v)+N2(w) <-> O2(v-2)+ N2(w+1) N2(v)+O2<->N2(v-1)+O2 N2(v)+O<->N2(v-1)+O O2(v)+O2(v’) <-> O2(v-1)+2O O2(v’)+O2<->2O+O2 O2(v’)+O <-> 3O O* + X<->N + X O* + X <-> N + X* O* + N2<-> NO + N N* + X<->N + X N* + X <-> N + X* N* + O2<-> NO + O NO Kinetics O2(v) + N <-> NO + O N2(v) + O <-> NO + N N + O + X <-> NO + X O2 & Air Elementary Processes

  13. BOLTZMANN EQUATION ELECTRON DISTRIBUTION density in phase space electron mean velocity collision and Magnetic accelleration Electric mean energy Free Electron Kinetics

  14. QUASI ISOTROPIC DISTRIBUTION INELASTIC SUPERELASTIC ELECTRON-ELECTRON ELASTIC isotropic anisotropic vy vy - + vx vx high low  Two Term Approximation

  15. Only drift velocity Electron enthalpy Internal enthalpy molar fractions Euler equations P T Approximate expansion cooling Boltzmann equation Master equations e-M rates Joule heating Level distribution molar fractions Electron drift energy Quasi 1D stationary Euler equations with with free electron kinetics and master equations APPROXIMATIONS Electron & Nozzle Flow SELF-CONSISTENT COUPLING

  16. VIBRATIONAL KINETICS PURE NITROGEN and AIR

  17. Tv N2 vibrational kinetics Gas and Vibrational Temperatures Vibrational non-equilibrium Tv > T Comparison of gas (T) and vibrational (Tv) reduced temperature profiles. T0=10000 K is the reservoir temperature.

  18. Determine vibrational temperature Determine global rates Global and state selective rates N2 vibrational kinetics Vibrational Distributions At the nozzle exit the tail of the vibrational distribution is populated by atom recombination.

  19. AIR vibrational kinetics Vibrational Distributions

  20. AIR vibrational kinetics Global rates N2+O->NO+N The low temperature trend cannot be reproduced by a multitemperature expressions.

  21. AIR vibrational kinetics NO molar fraction The concentration of NO increase again at the exit.

  22. ELECTRON +VIBRATIONAL KINETICS PURE NITROGEN and AIR

  23. ∆M% ≈ 10 ∆T% ≈ 25 Ionized N2 Mixture Macroscopic quantities a) Only Vibrational Kinetics b) (case a) + Electronically Excited State Kinetics (no e-M) c) (case b) + Electron Kinetics (Boltzmann Equation) + e-M

  24. N2(A) +N2(A) <-> N2(B)+N2(8) e +N2(v) <-> e+N2(v’<v) (superelastic) Ionized N2 Mixture Vibrational distributions a) Only Vibrational Kinetics b)(case a)+Electronically Excited State Kinetics (no e-M) c)(case b)+ Electron Kinetics (Boltzmann Equation) + e-M

  25. With e-e coll Without e-e coll Ionized N2 Mixture Electron distributions Superelastic collisions

  26. Ionized N2 Mixture Effect of atomic metastable (eedf) High electron density

  27. Ionized N2 Mixture Effect of atomic metastable (vdf) High electron density

  28. Ionized AIR Mach number Temperature

  29. MAGNETO -HYDRO -DYNAMICS ARGON

  30. FIELDS & GEOMETRY No Hall effect

  31. EFFECTS of E/N Speed & Mobility

  32. EFFECTS of E/N Molar fraction

  33. T0=7000 K E/N=0.5 Td EFFECTS of B Molar fractions

  34. T0=7000 K E/N=0.5 Td EFFECTS of B Electron mobility

  35. MACROSCOPICMODELS FROMSTATE-TO-STATE PURE NITROGEN

  36. RECOMBINATION REGIME 0d kinetics SPECIES TEMPERATURE

  37. RECOMBINATION REGIME Rates modeling GLOBAL DISSOCIATION RATES

  38. Linear dependence of the rates from the pressure; • Smooth dependence of the rates on the atomic • molar fraction; RECOMBINATION REGIME Relevant quantities

  39. RECOMBINATION REGIME Rate fitting Boundary Layer Nozzle

  40. Work in Progress A- Improving the kinetic model: state-to-state dissociation from QCT (Dr. F. Esposito, CNR-IMIP) B- Improving fluid dynamic model: From 1D to 2D (Dr. D. D’Ambrosio, Politecnico di Torino) C- MHD: inclusion of magnetic and electric fields configurations to include Hall effects and electric circuit modeling. D- REDUCED MODELS: finding a macroscopic model for air kinetics that accounts for nonequilibrium distributions (CAST).

More Related