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Nonequilibrium Processes and Plasma Radiation inHyperbolic Atmospheric Entry Flows
M. Lino da Silva, V. Guerra, J. Loureiro
(1) Centro de Fisica de Plasmas, Instituto Superior Tecnico, Lisboa, Portugal
3 August 2005
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Plan
Plan
1 Physical-Chemical-Radiative Problems of HyperbolicAtmospheric Entries
2 Example for Radiative Calculations: Mars Atmospheric Entries
3 Nonequilibrium Excitation Processes in Shock-Heated EntryFlows
4 Concluding Remarks and Perspectives
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Plan
Plan
1 Physical-Chemical-Radiative Problems of HyperbolicAtmospheric Entries
2 Example for Radiative Calculations: Mars Atmospheric Entries
3 Nonequilibrium Excitation Processes in Shock-Heated EntryFlows
4 Concluding Remarks and Perspectives
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Plan
Plan
1 Physical-Chemical-Radiative Problems of HyperbolicAtmospheric Entries
2 Example for Radiative Calculations: Mars Atmospheric Entries
3 Nonequilibrium Excitation Processes in Shock-Heated EntryFlows
4 Concluding Remarks and Perspectives
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Plan
Plan
1 Physical-Chemical-Radiative Problems of HyperbolicAtmospheric Entries
2 Example for Radiative Calculations: Mars Atmospheric Entries
3 Nonequilibrium Excitation Processes in Shock-Heated EntryFlows
4 Concluding Remarks and Perspectives
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Plan
1 Physical-Chemical-Radiative Problems of HyperbolicAtmospheric Entries
2 Example for Radiative Calculations: Mars Atmospheric Entries
3 Nonequilibrium Excitation Processes in Shock-Heated EntryFlows
4 Concluding Remarks and Perspectives
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Spacecraft Atmospheric Entries from Outer Space
Hyperbolic entry trajectories at v > 10km/s (From Mars v = 11 km/s).Space-Shuttle entries from orbit(parabolic trajectory) at v < 7 km/s.Plasma radiation important for overallheat fluxes calculation at v > 5 km/sExtreme nonequilibrium conditionsbehind the strong shock-wave,Ttr � Tvib, Ttr > 10, 000 K
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Spacecraft Atmospheric Entries from Outer Space
Hyperbolic entry trajectories at v > 10km/s (From Mars v = 11 km/s).Space-Shuttle entries from orbit(parabolic trajectory) at v < 7 km/s.Plasma radiation important for overallheat fluxes calculation at v > 5 km/sExtreme nonequilibrium conditionsbehind the strong shock-wave,Ttr � Tvib, Ttr > 10, 000 K
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Spacecraft Atmospheric Entries from Outer Space
Hyperbolic entry trajectories at v > 10km/s (From Mars v = 11 km/s).Space-Shuttle entries from orbit(parabolic trajectory) at v < 7 km/s.Plasma radiation important for overallheat fluxes calculation at v > 5 km/sExtreme nonequilibrium conditionsbehind the strong shock-wave,Ttr � Tvib, Ttr > 10, 000 K
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Estimation of the Spacecraft Aerodynamic and Thermal(Convective + Radiative) Loads
Gas radiative properties determined by thewavelength-dependent emission and absorption coefficients:
εul = NuAul∆Eul
αlu = NlBlu∆Eul
Besides the transition radiative properties (Aul ,Blu), the statepopulations need to be known (Nu,Nl), usually in astate-to-state approach
Dissociation (endothermic) and recombination (exotermic)chemical reactions affect convective heating loads and alsoneed to be treated in the state-to-state approach
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Estimation of the Spacecraft Aerodynamic and Thermal(Convective + Radiative) Loads
Gas radiative properties determined by thewavelength-dependent emission and absorption coefficients:
εul = NuAul∆Eul
αlu = NlBlu∆Eul
Besides the transition radiative properties (Aul ,Blu), the statepopulations need to be known (Nu,Nl), usually in astate-to-state approach
Dissociation (endothermic) and recombination (exotermic)chemical reactions affect convective heating loads and alsoneed to be treated in the state-to-state approach
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Estimation of the Spacecraft Aerodynamic and Thermal(Convective + Radiative) Loads
Gas radiative properties determined by thewavelength-dependent emission and absorption coefficients:
εul = NuAul∆Eul
αlu = NlBlu∆Eul
Besides the transition radiative properties (Aul ,Blu), the statepopulations need to be known (Nu,Nl), usually in astate-to-state approach
Dissociation (endothermic) and recombination (exotermic)chemical reactions affect convective heating loads and alsoneed to be treated in the state-to-state approach
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Estimation of the Spacecraft Aerodynamic and Thermal(Convective + Radiative) Loads
Gas radiative properties determined by thewavelength-dependent emission and absorption coefficients:
εul = NuAul∆Eul
αlu = NlBlu∆Eul
Besides the transition radiative properties (Aul ,Blu), the statepopulations need to be known (Nu,Nl), usually in astate-to-state approach
Dissociation (endothermic) and recombination (exotermic)chemical reactions affect convective heating loads and alsoneed to be treated in the state-to-state approach
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Estimation of the Spacecraft Aerodynamic and Thermal(Convective + Radiative) Loads
Gas radiative properties determined by thewavelength-dependent emission and absorption coefficients:
εul = NuAul∆Eul
αlu = NlBlu∆Eul
Besides the transition radiative properties (Aul ,Blu), the statepopulations need to be known (Nu,Nl), usually in astate-to-state approach
Dissociation (endothermic) and recombination (exotermic)chemical reactions affect convective heating loads and alsoneed to be treated in the state-to-state approach
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Plan
1 Physical-Chemical-Radiative Problems of HyperbolicAtmospheric Entries
2 Example for Radiative Calculations: Mars Atmospheric Entries
3 Nonequilibrium Excitation Processes in Shock-Heated EntryFlows
4 Concluding Remarks and Perspectives
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Simulation of Atmospheric Entry Radiation
Two different issues: calculation of transition probabilities(quantum mechanics models) and calculation of quantumstates populations (collisional-radiative models)
Calculation of transition probabilities can now be routinelycarried for most chemical species
No complete collisional-radiative model exists for thesimulation of atmospheric entry flows. Most simulationsassume Boltzmann equilibrium conditions
Additional issue (not discussed here): radiation transport →different numerical models available
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Simulation of Atmospheric Entry Radiation
Two different issues: calculation of transition probabilities(quantum mechanics models) and calculation of quantumstates populations (collisional-radiative models)
Calculation of transition probabilities can now be routinelycarried for most chemical species
No complete collisional-radiative model exists for thesimulation of atmospheric entry flows. Most simulationsassume Boltzmann equilibrium conditions
Additional issue (not discussed here): radiation transport →different numerical models available
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Simulation of Atmospheric Entry Radiation
Two different issues: calculation of transition probabilities(quantum mechanics models) and calculation of quantumstates populations (collisional-radiative models)
Calculation of transition probabilities can now be routinelycarried for most chemical species
No complete collisional-radiative model exists for thesimulation of atmospheric entry flows. Most simulationsassume Boltzmann equilibrium conditions
Additional issue (not discussed here): radiation transport →different numerical models available
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Simulation of Atmospheric Entry Radiation
Two different issues: calculation of transition probabilities(quantum mechanics models) and calculation of quantumstates populations (collisional-radiative models)
Calculation of transition probabilities can now be routinelycarried for most chemical species
No complete collisional-radiative model exists for thesimulation of atmospheric entry flows. Most simulationsassume Boltzmann equilibrium conditions
Additional issue (not discussed here): radiation transport →different numerical models available
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Atmospheric Entry Radiation Research Activities at IST
Line-by-Line numerical code SPARTAN: Simulation ofPlasmA Radiation in ThermodynAmic Nonequilibrium
63 atomic and molecular bound-bond, bound-free(Photodissociation, Photoionization, Photodetachment), andfree-free (Bremsstrahlung) transitions from C, N, and Ocontaining species (Earth & Mars)
Online Gas & Plasma Radiation Database (GPRD) athttp://cfp.ist.utl.pt/radiation for providing the scientificcommunity with a database for molecular radiation
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Atmospheric Entry Radiation Research Activities at IST
Line-by-Line numerical code SPARTAN: Simulation ofPlasmA Radiation in ThermodynAmic Nonequilibrium
63 atomic and molecular bound-bond, bound-free(Photodissociation, Photoionization, Photodetachment), andfree-free (Bremsstrahlung) transitions from C, N, and Ocontaining species (Earth & Mars)
Online Gas & Plasma Radiation Database (GPRD) athttp://cfp.ist.utl.pt/radiation for providing the scientificcommunity with a database for molecular radiation
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Atmospheric Entry Radiation Research Activities at IST
Line-by-Line numerical code SPARTAN: Simulation ofPlasmA Radiation in ThermodynAmic Nonequilibrium
63 atomic and molecular bound-bond, bound-free(Photodissociation, Photoionization, Photodetachment), andfree-free (Bremsstrahlung) transitions from C, N, and Ocontaining species (Earth & Mars)
Online Gas & Plasma Radiation Database (GPRD) athttp://cfp.ist.utl.pt/radiation for providing the scientificcommunity with a database for molecular radiation
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Radiative Transition Probabilities Calculation
Systematic calculation of thetransition probabilities Aul
by an ”ab-initio” method
Reconstruction of themolecular potentials usingthe RKR method andresolution of the Schrodingerequation
Example for the CN Violet System
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Spectral Simulation of the Equilibrium Radiative Propertiesof a Martian-Type Plasma
High resolution calculation of emission and absorptioncoefficients for a 100A–100µm spectral range at 1000, 5000,and 10000 K using the full spectroscopic database (49transitions)
30 min calculation time on a laptop for a spectrum of∼ 105 − 106 points
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Spectral Simulation of the Equilibrium Radiative Propertiesof a Martian-Type Plasma
High resolution calculation of emission and absorptioncoefficients for a 100A–100µm spectral range at 1000, 5000,and 10000 K using the full spectroscopic database (49transitions)
30 min calculation time on a laptop for a spectrum of∼ 105 − 106 points
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Radiative properties at 1000 K
Emission coefficient Absorption coefficient
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Radiative properties at 5000 K
Emission coefficient Absorption coefficient
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Radiative properties at 10000 K
Emission coefficient Absorption coefficient
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Equilibrium Radiation of a Martian-type Gas at 4300 Pafor the Temperature Range 200-10000 K
Selected pressure of 4300 Pa which corresponds to thepost-shock pressure in a aerocapture manoeuver in Marsatmosphere
Calculation of the gas optically thin radiative power
Calculation of the individual contribution of each system tothe overall radiative power
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Equilibrium Radiation of a Martian-type Gas at 4300 Pafor the Temperature Range 200-10000 K
Selected pressure of 4300 Pa which corresponds to thepost-shock pressure in a aerocapture manoeuver in Marsatmosphere
Calculation of the gas optically thin radiative power
Calculation of the individual contribution of each system tothe overall radiative power
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Equilibrium Radiation of a Martian-type Gas at 4300 Pafor the Temperature Range 200-10000 K
Selected pressure of 4300 Pa which corresponds to thepost-shock pressure in a aerocapture manoeuver in Marsatmosphere
Calculation of the gas optically thin radiative power
Calculation of the individual contribution of each system tothe overall radiative power
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Quantitative Radiative Properties of a Martian-type Gas at4300 Pa for the Temperature Range 200-10000 K
Optically thin radiative power of a Martian-type gas at4300 Pa, in the temperature range 200-10000 K
Contribution from each atomic and molecular system
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Selection of an Appropriate Spectral Database
For equilibrium conditions, few atomic and molecular systemscontribute for overall radiative flux
Not to be extrapolated to nonequilibrium conditions! (evenfor Boltzmann equilibrium of the flow, e.g. C2 Swan Bands).Also for non-optically thin gas must account for absorbingtransitions, e. g. O2 Schumann–Runge
Must have the most reduced set without losing precision(lower number of calculated lines)
More difficult task in strong nonequilibrium conditions! (e. g.behind shock-waves)
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Selection of an Appropriate Spectral Database
For equilibrium conditions, few atomic and molecular systemscontribute for overall radiative flux
Not to be extrapolated to nonequilibrium conditions! (evenfor Boltzmann equilibrium of the flow, e.g. C2 Swan Bands).Also for non-optically thin gas must account for absorbingtransitions, e. g. O2 Schumann–Runge
Must have the most reduced set without losing precision(lower number of calculated lines)
More difficult task in strong nonequilibrium conditions! (e. g.behind shock-waves)
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Selection of an Appropriate Spectral Database
For equilibrium conditions, few atomic and molecular systemscontribute for overall radiative flux
Not to be extrapolated to nonequilibrium conditions! (evenfor Boltzmann equilibrium of the flow, e.g. C2 Swan Bands).Also for non-optically thin gas must account for absorbingtransitions, e. g. O2 Schumann–Runge
Must have the most reduced set without losing precision(lower number of calculated lines)
More difficult task in strong nonequilibrium conditions! (e. g.behind shock-waves)
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Selection of an Appropriate Spectral Database
For equilibrium conditions, few atomic and molecular systemscontribute for overall radiative flux
Not to be extrapolated to nonequilibrium conditions! (evenfor Boltzmann equilibrium of the flow, e.g. C2 Swan Bands).Also for non-optically thin gas must account for absorbingtransitions, e. g. O2 Schumann–Runge
Must have the most reduced set without losing precision(lower number of calculated lines)
More difficult task in strong nonequilibrium conditions! (e. g.behind shock-waves)
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Plan
1 Physical-Chemical-Radiative Problems of HyperbolicAtmospheric Entries
2 Example for Radiative Calculations: Mars Atmospheric Entries
3 Nonequilibrium Excitation Processes in Shock-Heated EntryFlows
4 Concluding Remarks and Perspectives
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Challenges Associated to the Development of aNonequilibrium Entry Flow Model
Definition of a self-consistent rate equations set valid inatmospheric entry conditions
Also computational issues! Must retain a reduced butaccurate set of rate equations
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Challenges Associated to the Development of aNonequilibrium Entry Flow Model
Definition of a self-consistent rate equations set valid inatmospheric entry conditions
Also computational issues! Must retain a reduced butaccurate set of rate equations
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Kinetic Scheme Features for Entry Flows
Different processes behind theshock-wave lead to the formationof an entry plasma
Dissociation, ionization processeswith Etr−rot � Evib,Eel
V–E Excitation of molecularelectronic levels will contribute forgas radiation and Penningionization(N2(A)+N2(a’)�N2(X)+N+
2 (X))
Maxwellian EEDF may be assumedas the electrons are thermalized
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Kinetic Scheme Features for Entry Flows
Different processes behind theshock-wave lead to the formationof an entry plasma
Dissociation, ionization processeswith Etr−rot � Evib,Eel
V–E Excitation of molecularelectronic levels will contribute forgas radiation and Penningionization(N2(A)+N2(a’)�N2(X)+N+
2 (X))
Maxwellian EEDF may be assumedas the electrons are thermalized
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Kinetic Scheme Features for Entry Flows
Different processes behind theshock-wave lead to the formationof an entry plasma
Dissociation, ionization processeswith Etr−rot � Evib,Eel
V–E Excitation of molecularelectronic levels will contribute forgas radiation and Penningionization(N2(A)+N2(a’)�N2(X)+N+
2 (X))
Maxwellian EEDF may be assumedas the electrons are thermalized
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Kinetic Scheme Features for Entry Flows
Different processes behind theshock-wave lead to the formationof an entry plasma
Dissociation, ionization processeswith Etr−rot � Evib,Eel
V–E Excitation of molecularelectronic levels will contribute forgas radiation and Penningionization(N2(A)+N2(a’)�N2(X)+N+
2 (X))
Maxwellian EEDF may be assumedas the electrons are thermalized
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Reproduction of Inflight Flow Conditions in Ground-TestFacilities
Shock-tube facilities typical offorebody flows, closer to entryflow conditions (Etr > Eel) butshort test times (<1 ms) andtypically with v<10 km/sPlasma facilities typical ofafterbody flows and fartherfrom entry flow conditions(Etr < Eel) but virtuallyunlimited test times
Simulation of entry-like flows in different ground-testfacilities
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Reproduction of Inflight Flow Conditions in Ground-TestFacilities
Shock-tube facilities typical offorebody flows, closer to entryflow conditions (Etr > Eel) butshort test times (<1 ms) andtypically with v<10 km/sPlasma facilities typical ofafterbody flows and fartherfrom entry flow conditions(Etr < Eel) but virtuallyunlimited test times
Simulation of entry-like flows in different ground-testfacilities
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Simulation of Dissociation Processes Behind HyperbolicShock-Waves
Translational Temperatures up to 100,000 KV–T & V–V–T dissociation processes simulated by the FHOmodel
Model more accurate than FOPT models, and compares wellwith more complex mehods (QCT – Billing, Lagana)
Model developed in the 60’s (Rapp, Kerner, Treanor,Zelechow) and extended by Adamovich in the 90’s
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Simulation of Dissociation Processes Behind HyperbolicShock-Waves
Translational Temperatures up to 100,000 KV–T & V–V–T dissociation processes simulated by the FHOmodel
Model more accurate than FOPT models, and compares wellwith more complex mehods (QCT – Billing, Lagana)
Model developed in the 60’s (Rapp, Kerner, Treanor,Zelechow) and extended by Adamovich in the 90’s
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Simulation of Dissociation Processes Behind HyperbolicShock-Waves
Translational Temperatures up to 100,000 KV–T & V–V–T dissociation processes simulated by the FHOmodel
Model more accurate than FOPT models, and compares wellwith more complex mehods (QCT – Billing, Lagana)
Model developed in the 60’s (Rapp, Kerner, Treanor,Zelechow) and extended by Adamovich in the 90’s
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Simulation of Dissociation Processes Behind HyperbolicShock-Waves
Translational Temperatures up to 100,000 KV–T & V–V–T dissociation processes simulated by the FHOmodel
Model more accurate than FOPT models, and compares wellwith more complex mehods (QCT – Billing, Lagana)
Model developed in the 60’s (Rapp, Kerner, Treanor,Zelechow) and extended by Adamovich in the 90’s
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
The Forced Harmonic Oscillator Model
V–T probabilities for collinear atom-diatom non-reactivecollisions (Kerner:1958) & (Treanor:1965)
P(i → f , ε) = i!f !εi+f exp (−ε)
∣∣∣∣∣n∑
r=0
(−1)r
r !(i − r)!(f − r)!εr
∣∣∣∣∣2
,
n = min(i, f ).
V–V–T probabilities for collinear diatom-diatom collisions(Zelechow:1968)
P(i1, i2 → f1, f2, ε, ρ) =
∣∣∣∣∣∣n∑
g=1
(−1)(i12−g+1) × Ci12g,i2+1C
f12g,f2+1
ε12
(i12+f12−2g+2)exp (−ε/2)
×√
(i12 − g + 1)!(f12 − g + 1)! exp [−i(f12 − g + 1)ρ] ×n−g∑l=0
(−1)l
(i12 − g + 1− l)!(f12 − g + 1− l)!l!εl
∣∣∣∣∣∣2
,
i12 = i1 + i2, f12 = f1 + f2,
n = min(i1 + i2 + 1, f1 + f2 + 1).
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Assumptions for Shock-Heated Flows
V–V–T reaction rates for the 59 levels of: N2: 594 ∼ 107
⇒ P(i1, all → f1, all, ε, ρ) = P(i1 → f1, ε). (Adamovich:1995)
Dissociation occurs for a transition to a vibrational levelv > 59 (quasibound level)
P(i →, ε) = P(i → vqbound , ε) · Pdecay ,
Pdecay ∼ 1
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Assumptions for Shock-Heated Flows
V–V–T reaction rates for the 59 levels of: N2: 594 ∼ 107
⇒ P(i1, all → f1, all, ε, ρ) = P(i1 → f1, ε). (Adamovich:1995)
Dissociation occurs for a transition to a vibrational levelv > 59 (quasibound level)
P(i →, ε) = P(i → vqbound , ε) · Pdecay ,
Pdecay ∼ 1
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Level Energies Calculations
Inaccurate determinations oflevels energy separationsnear and above thedissociation limit willprovide inaccurate transitionprobabilities
Polynomial expansionsprevent the calculation ofquasibound vibrational levelsvqbound > 81 Vibrational levels energies for N2
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Level Energies Calculations
Inaccurate determinations oflevels energy separationsnear and above thedissociation limit willprovide inaccurate transitionprobabilities
Polynomial expansionsprevent the calculation ofquasibound vibrational levelsvqbound > 81 Vibrational levels energies for N2
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Possible Simplifications
Asymptotical expressions by Adamovich simplify calculationsand allow for rotation effects
P(5 → 4)
P(i → f , ε) = J2s (2√
nsε)
P(15 → 30)
J2s (2√
nsε) ∼= (ns )s
(s!)2εs exp
(−2nsεs+1
)No approximations used here. Variable precision arithmetics inMATLAB (64 digits numbers) used in calculations
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Possible Simplifications
Asymptotical expressions by Adamovich simplify calculationsand allow for rotation effects
P(5 → 4)
P(i → f , ε) = J2s (2√
nsε)
P(15 → 30)
J2s (2√
nsε) ∼= (ns )s
(s!)2εs exp
(−2nsεs+1
)No approximations used here. Variable precision arithmetics inMATLAB (64 digits numbers) used in calculations
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Validation of the FHO model
Comparison with experimentaldata and QCT calculations byBilling show very goodagreement in general
Failure of the FHO model fornear-resonant transitions atlower temperatures (notimportant for shock-heatedflows)
Near 100,000K reaction ratesachieve a plateau
Single-quantum V–V rates for N2–N2 (0, 1→1, 0)and (0, 1→20, 19) transitions and O2–N2 (0, 1→1,
0) transitions. − and −−, FHO model. ×,calculations of Billing:1979 for N2–N2. �,
interpolation of experimental data for N2–O2 (1,0→0, 1), Taylor:1969
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Validation of the FHO model
Comparison with experimentaldata and QCT calculations byBilling show very goodagreement in general
Failure of the FHO model fornear-resonant transitions atlower temperatures (notimportant for shock-heatedflows)
Near 100,000K reaction ratesachieve a plateau
Single-quantum V–V rates for N2–N2 (0, 1→1, 0)and (0, 1→20, 19) transitions and O2–N2 (0, 1→1,
0) transitions. − and −−, FHO model. ×,calculations of Billing:1979 for N2–N2. �,
interpolation of experimental data for N2–O2 (1,0→0, 1), Taylor:1969
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Validation of the FHO model
Comparison with experimentaldata and QCT calculations byBilling show very goodagreement in general
Failure of the FHO model fornear-resonant transitions atlower temperatures (notimportant for shock-heatedflows)
Near 100,000K reaction ratesachieve a plateau
Single-quantum V–V rates for N2–N2 (0, 1→1, 0)and (0, 1→20, 19) transitions and O2–N2 (0, 1→1,
0) transitions. − and −−, FHO model. ×,calculations of Billing:1979 for N2–N2. �,
interpolation of experimental data for N2–O2 (1,0→0, 1), Taylor:1969
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Simulation of Simplified Shock Geometries for Nitrogenflows
V–T reaction rate database calculated up to Ttr = 100, 000Kfor 100 levels of N2
Simulation of a Shock at an altitude of 76 km and fixedtranslational temperatures of 1,000, 10,000 and 100,000 K.
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Simulation of Simplified Shock Geometries for Nitrogenflows
V–T reaction rate database calculated up to Ttr = 100, 000Kfor 100 levels of N2
Simulation of a Shock at an altitude of 76 km and fixedtranslational temperatures of 1,000, 10,000 and 100,000 K.
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Shock Simulation at 1000 K
Reaction Rates Database at 1000 K Time Evolution of the VDF
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Shock Simulation at 10000 K
Reaction Rates Database at 10000 K Time Evolution of the VDF
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Shock Simulation at 100000 K
Reaction Rates Database at 100000 K Time Evolution of the VDF
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Evolution of the Molecular Dissociation at Different ShockTemperatures
Dissociation times range frommore than 1 s for T ≤ 5, 000Kto 1 ns for T = 100, 000KFor lower temperatures,“ladder-climbing” phenomenaenhance dissociation after acertain incubation time
At higher temperatures,(T ≥ 50, 000K) dissociationproceeds equiprobably from allthe vibrational levels
Time evolution of N2 dissociation at different shocktemperatures
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Evolution of the Molecular Dissociation at Different ShockTemperatures
Dissociation times range frommore than 1 s for T ≤ 5, 000Kto 1 ns for T = 100, 000KFor lower temperatures,“ladder-climbing” phenomenaenhance dissociation after acertain incubation time
At higher temperatures,(T ≥ 50, 000K) dissociationproceeds equiprobably from allthe vibrational levels
Time evolution of N2 dissociation at different shocktemperatures
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Evolution of the Molecular Dissociation at Different ShockTemperatures
Dissociation times range frommore than 1 s for T ≤ 5, 000Kto 1 ns for T = 100, 000KFor lower temperatures,“ladder-climbing” phenomenaenhance dissociation after acertain incubation time
At higher temperatures,(T ≥ 50, 000K) dissociationproceeds equiprobably from allthe vibrational levels
Time evolution of N2 dissociation at different shocktemperatures
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Plan
1 Physical-Chemical-Radiative Problems of HyperbolicAtmospheric Entries
2 Example for Radiative Calculations: Mars Atmospheric Entries
3 Nonequilibrium Excitation Processes in Shock-Heated EntryFlows
4 Concluding Remarks and Perspectives
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Conclusions
Development of radiation databases is a straightforward task,but needs extensive validations
Developed state-to-state models need to be valid for the mostextreme hyperbolic shock-waves. Importance of multiquantumtransitions
Computation time issues remain determinant as they preventfull-use of line-by-line calculations and state-to-state models.The errors induced by the used approximations (Boltzmannequilibrium, band models) remain unknown
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Conclusions
Development of radiation databases is a straightforward task,but needs extensive validations
Developed state-to-state models need to be valid for the mostextreme hyperbolic shock-waves. Importance of multiquantumtransitions
Computation time issues remain determinant as they preventfull-use of line-by-line calculations and state-to-state models.The errors induced by the used approximations (Boltzmannequilibrium, band models) remain unknown
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Conclusions
Development of radiation databases is a straightforward task,but needs extensive validations
Developed state-to-state models need to be valid for the mostextreme hyperbolic shock-waves. Importance of multiquantumtransitions
Computation time issues remain determinant as they preventfull-use of line-by-line calculations and state-to-state models.The errors induced by the used approximations (Boltzmannequilibrium, band models) remain unknown
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Perspectives
V–T dissociation models should include effects of molecularrotation
V–E processes need more theoretical developments. Onlyavailable experimental data obtained for gas-dischargeapplications with Ttr ∼ 300KRadiation re-absorption may be important for hyperbolic flows(see Park 2004 for Galileo probe entry simulations)
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Perspectives
V–T dissociation models should include effects of molecularrotation
V–E processes need more theoretical developments. Onlyavailable experimental data obtained for gas-dischargeapplications with Ttr ∼ 300KRadiation re-absorption may be important for hyperbolic flows(see Park 2004 for Galileo probe entry simulations)
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
Hyperbolic Atmospheric EntriesMars Atmospheric Entries Radiation
Nonequilibrium Processes in Shock-Heated FlowsConclusions & Perspectives
Perspectives
V–T dissociation models should include effects of molecularrotation
V–E processes need more theoretical developments. Onlyavailable experimental data obtained for gas-dischargeapplications with Ttr ∼ 300KRadiation re-absorption may be important for hyperbolic flows(see Park 2004 for Galileo probe entry simulations)
Mario Lino da Silva Nonequilibrium Processes & Plasma Radiation
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