AEROFAST : THERMAL/ABLATION ANALYSIS OF THE FRONT HEAT SHIELD FOR A MARTIAN AEROCAPTURE MISSION
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AEROFAST: THERMAL/ABLATION ANALYSIS OF THE FRONT HEAT SHIELD FOR A MARTIAN AEROCAPTURE MISSION A.J. van Eekelen, G. Pinaud, J.-M. Bouilly Modelling approach Loads and boundary conditions Thermal response calculation Finite element model Problem description Results 1D calculation 3D calculation RT E N i i N c v N v i i i i i i e A 1 1 1 P K P . g g P h m T T c H . t T D S q T t D S T n q w e w R i i , , , , , 4 4 1 cos 2 1 , , 0 , , , , q t T D S q t T D S q w w t T D S q t T D S q q w w , , 180 , , , 0 , T s s In the frame of the AEROFAST (AEROcapture for Future space tranSporTation) R&D project (FP7), we aim to increase the TRL level of a Martian Aerocapture mission. The Aerocapture trajectory and maneuver results in significant aerodynamic heating, necessitating a Thermal Protection System (TPS). The selected shield has an Apollo like shape with a 3.6 m diameter. The thermal and ablation behavior of a low density (phenolic impregnated) cork TPS is analyzed. The heat shield is subjected to a 3D convection and radiation load obtained for a CO 2 Martian atmosphere. Tim e(s) H eatflux(T w =300K):[kW /m 2 ] Altitude(km ) 0 200 400 600 800 1000 1200 1400 0 50 100 150 200 250 300 350 0 20 40 60 80 100 120 W indward: S/D=0.475 Leew ard: S/D =0.0 Maxim um coldwallheatloadshistory on leeward and windward Conclusions S/ D=0.482 S/ D=0.561 Distancefrom outersurface:[m] Density:[kg/m 3 ] 0 0.005 0.01 0.015 0.02 150 200 250 300 350 400 450 S/D=0.00 S/D=0.482 S /D =0.561 TPS thickness:[m m ] Gluetem perature:[K] 14 15 16 17 18 19 20 400 420 440 460 480 500 Time:[s] CoG transversaldisplacement:[mm] CoG axialdisplacement:[mm] 0 200 400 600 800 1000 1200 1400 0 10 20 30 40 -3 -2.5 -2 -1.5 -1 -0.5 0 HEAT SHIELD CoG DISPLACEM ENT Position S/D :[-] A ngularposition :[deg] 0 0.1 0.2 0.3 0.4 0.5 0 50 100 150 Recession:[m m ] 4.2 4 3.8 3.6 3.4 3.2 3 2.8 2.6 2.4 2.2 2 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 LEEW ARD W INDW ARD FR O N TS H IE LD A 3D finite element model, including charring and ablation, has been implemented in SAMCEF. A preliminary TPS design of a phenolic impregnated cork material has been obtained, while complementary work on advanced (cork based) TPS material modeling is underway within the AEROFAST project. CFRP Aluminum honeycomb CFRP Silicon based glue Cork based TPS Through the thickness and 3D finite element distribut Heat flux at t = 160. s [kw/m 2 ] Edge cross-section for = 180° The elements have multiple degrees of freedom per node (T,P,, 1 , …, n ), and the balance equations are implemented on a moving mesh (transport terms). The 3D half model consists of 58.894 elements with a total of 144.031 degrees of freedom. Energy balance: Mass conservation: Arrhenius-type charring law: Boundary balance: Explicit ablation law: 3D transient temperature dependent (convection) heat flux, evaluated using an Euler-boundary layer computation and empirical correlation adapted to CO 2 gas. Parametric analysis to determine the TPS thickness (17 mm), for a maximum allowable structure temperature of 180 °C.
description
Cork based TPS. Silicon based glue. CFRP. Aluminum honeycomb. CFRP. S/D=0.482. S/D=0.561. AEROFAST : THERMAL/ABLATION ANALYSIS OF THE FRONT HEAT SHIELD FOR A MARTIAN AEROCAPTURE MISSION A.J. van Eekelen, G. Pinaud, J.-M. Bouilly. Problem description. - PowerPoint PPT Presentation
Transcript of AEROFAST : THERMAL/ABLATION ANALYSIS OF THE FRONT HEAT SHIELD FOR A MARTIAN AEROCAPTURE MISSION
AEROFAST: THERMAL/ABLATION ANALYSIS OF THE FRONT HEAT SHIELD FOR A MARTIAN AEROCAPTURE MISSION
A.J. van Eekelen, G. Pinaud, J.-M. Bouilly
Modelling approach Loads and boundary conditions
Thermal response calculation
Finite element model
Problem description
Results
1D calculation
3D calculation
RTE
Ni
i
Ncv
Nvii
iiii eA 111
PKP.
ggP hmTTcH .
tTDSqTtDSTnq wewRii ,,,,, 44
1cos2
1,,0,,,, qtTDSqtTDSq ww
tTDSqtTDSqq ww ,,180,,,0,
Tss
In the frame of the AEROFAST (AEROcapture for Future space tranSporTation) R&D project (FP7), we aim to increase the TRL level of a Martian Aerocapture mission.
The Aerocapture trajectory and maneuver results in significant aerodynamic heating, necessitating a Thermal Protection System (TPS). The selected shield has an Apollo like shape with a 3.6 m diameter.
The thermal and ablation behavior of a low density (phenolic impregnated) cork TPS is analyzed. The heat shield is subjected to a 3D convection and radiation load obtained for a CO2 Martian atmosphere.
Time (s)
He
at
flux(
Tw=
30
0K
):[k
W/m
2]
Alti
tud
e(k
m)
0 200 400 600 800 1000 1200 14000
50
100
150
200
250
300
350
0
20
40
60
80
100
120
Windward: S/D=0.475Leeward: S/D=0.0
Maximum cold wall heat loads historyon leeward and windward
Conclusions
S/D=0.482
S/D=0.561
Distance from outer surface: [m]
Den
sity
:[kg
/m3]
0 0.005 0.01 0.015 0.02150
200
250
300
350
400
450
S/D =0.00S/D =0.482S/D=0.561
TPS thickness: [mm]
Glu
ete
mp
era
ture
:[K
]
14 15 16 17 18 19 20400
420
440
460
480
500
Time: [s]Co
Gtr
an
svers
ald
isp
lace
men
t:[m
m]
Co
Gaxi
ald
isp
lace
men
t:[m
m]
0 200 400 600 800 1000 1200 14000
10
20
30
40
-3
-2.5
-2
-1.5
-1
-0.5
0HEAT SHIELD CoG DISPLACEMENT
Position S/D: [-]
Angula
rposi
tion
:[d
eg]
0 0.1 0.2 0.3 0.4 0.50
50
100
150
Recession: [mm]4.243.83.63.43.232.82.62.42.221.81.61.41.210.80.60.40.20
LEEWARD
WINDWARD
FR
ON
TS
HIE
LD
A 3D finite element model, including charring and ablation, has been implemented in SAMCEF. A preliminary TPS design of a phenolic impregnated cork material has been obtained, while complementary work on advanced (cork based) TPS material modeling is underway within the AEROFAST project.
CFRP
Aluminum honeycomb
CFRP
Silicon based glue
Cork based TPS
Through the thickness and 3D finite element distribution
Heat flux at t = 160. s [kw/m2]
Edge cross-section for = 180°
The elements have multiple degrees of freedom per node (T,P,,1,…,n), and the balance equations are implemented on a moving mesh (transport terms). The 3D half model consists of 58.894 elements with a total of 144.031 degrees of freedom.
Energy balance:Mass conservation: Arrhenius-type charring law:Boundary balance:Explicit ablation law:
3D transient temperature dependent (convection) heat flux, evaluated using an Euler-boundary layer computation and empirical correlation adapted to CO2 gas.
Parametric analysis to determine the TPS thickness (17 mm), for a maximum allowable structure temperature of 180 °C.
