Overall Preliminary Design of the Thermal

Transcription

Overall Preliminary Design of the Thermal Protection System for a
Long Range Hypersonic Rocket-powered Passenger Vehicle
(Spaceliner)
7th European Workshop on Thermal Protection Systems and Hot Structures
8th April 2013
Nicole Garbers
Space Launcher Systems Analysis (SART), DLR, 28359 Bremen, Germany
SART Systemanalyse Raumtransport
www.DLR.de •
Overview
- SpaceLiner
- TPS designing tool TOP
- Preliminary TPS design passenger capsule (SpaceLiner)
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SpaceLiner
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Preliminary design needs fast engineering
methods
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Physical Modell
Flight trajectories (nominal & abort)
altitude [km]
DIFFERENT TRAJECTORIES
(ORBITER)
~ 30 flight points
per trajectory
Mach Number
altitude
angle of attack
50
temperature at each
grid point for
selected flight points
HOTSOSE
0
0
2000
4000
time[s]
6000
Recall for each
trajectory
2
0
-2
60
50
15
40
Temperature [K]
overall maximum
temperature
6
Max. temperature for selected surface Max.x heat
10 flux for selected surface
3000
2
NOMINAL
NOMINAL
ABORT
HP
ABORT HP
2500
1.5
ABORT BS
ABORT BS
Heat flux [W/m²]
<=600 K
600 <= ... < 800 K
800 <= ... < 1400 K
1400 <= ... < 2507.311 K
2000
1500
1000
time-dependent
temperature
profile for each grid
1
point
0.5
10
30
5
0
500
20
-5
10
-10
-15
0
2000
Time [s]
4000
0
0
2000
Time [s]
4000
0
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For each trajectory:
Create „summarized“
(according grid ponts) heat
profile for each TPS area
Example for one trajectory:
Max. temperature for selected surface
1400
1300
Temperatur [K]
Physical Modell
1200
1100
1000
900
800
700
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0
2000
Time [s]
4000
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Physical Modell
(only conduction, 1D)
Max. temperature for selected surface
1400
Temperatur [K]
1300
𝜕𝜕
𝜕
𝜕𝜕
𝜆
= 𝜌𝑐𝑝
𝜕𝜕
𝜕𝜕
𝜕𝜕
1200
1100
1000
MATLAB => pdepe
Solve initial-boundary value problems for
parabolic-elliptic PDEs in 1-D
900
800
0
2000
Time [s]
4000
Time-depending
boundary conditions
for heat equation
Temperature [k]
700
User-given/ adapted
- Material properties
=> First guess of thickness
- Max. allowed structure
temperature
1500
NO
1000
500
0
0
20
20
40
10
60
80
100
0
Time steps
Grid points
Max. structure temperature ~ max. allowed structure temperature
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Validation of the physical modell: Space Shuttle
FRSI (blue, < 390 K)
literature: 1.62 cm
calculated: 1.21 cm
LRSI (turquoise, 390 – 500 K)
literature: 2.853 cm
calculated: 2.5 cm
RCC (red, > 1300 K)
literature: 8.9 cm
calculated: 7.9 cm
Difference due to
- use of nominal trajectory for calculation (not the critical one which would
be basis for real case)
- only assumption of 1D heat flux
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Simulation scenarios for passenger capsule
TPS Mass (Capsule)
6000
structure temperature:
298 K (light)
5500
TPS Mass [kg]
293 K (light)
303 K (light)
5000
400 K (light)
4500
293 K (thin)
4000
298 K (thin)
3500
303 K (thin)
until landing until landing + until landing +
300s
600s
400 K (thin)
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Passenger capsule
optimization:thin
Temperature
Thicknes
Mass
Material
s [m]
[kg]
(303 K) until landing + 300
Upper half
AETB-12
0.1021
289.50
< 900 K
Upper half
AETB-12
0.1021
1961.48
900 – 1200 K
Lower half
AETB-12
0.0566
165.99
< 1200 K
Lower half
AETB-12
0.0600
189.18
1200 – 1300 K
Lower half
AETB-12
0.0627
149.17
1300 – 1400 K
Lower half
AETB-12
0.0659
113.12
1400 – 1500 K
Lower half
AETB-12
0.0674
567.71
1500 – 1600 K
Lower half
CMC
0.2198
197.83
1600 – 1700 K
Lower half
CMC
0.2198
10.01
1700 – 1850 K
Nose section
AVCOAT
0.1330
1347
Sum
4991.0
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Summary
- Fast engineering modell works well for TPS predesigning process !
=> acceptable validation done
=> fast enough to analyse hugh number of modells during
predesign
- TPS Spaceliner
=> TPS mass is a critical factor in the designing process
=> Material thickness has to be a compromise between „thin“ and
„light“
=> combination between a air-condition cooling system and a
passive TPS can be useful.
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Overall Preliminary Design of the Thermal

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