1. AAE 450: Aero-thermodynamics
Preliminary analysis and literature survey of design concepts for atmospheric Entry of MARS. By
Santosh J. Kuruvilla
01/23/2001

2. Contents:
Vehicle types, characteristics, and requirements for expected mission.
Modeling atmospheric flight:
EOM’s, Stagnation point heat flux calculations,constraints, and assumptions.
Comparison of analysis to existing published data.
Future additions to the model, and required analysis for the given mission.
Related experiences and course work.

3. Vehicle Types Lifting Body Ballistic Winged Low Heat Load
X-24
Mercury
Enterprise
Low Heat Load
Simple Booster Configuration
Maximum Volume
Low weight
Low L/D
Vertical Landing
Low Heat Load
Good Booster compatibility
High Volume
Relatively Low structural
weight
Moderate Deceleration
Moderate L/D
Horizontal Landing
High Heat Load
Poor Booster Compatibility
Low Volume
High Weight
Low Deceleration
High L/D
Horizontal Landings

4. Mission Requirements High Volume Low Weight Low Heat loading
Hypersonic L/D 0.3 to 1
Good Booster compatibility
Moderate Controllability using lifting surfaces, to effect plane changes or reduce velocity. =
Lifting Body

5. Dynamic Model for atmospheric flight.
EOM’s
h : Altitude above surface
V: Velocity
: Flight Path angle
: Heading angle
 : Latitude
 : Longitude
: Bank angle
L: Lift
D: Drag
Rm: Radius of mars
: Gravitational Const
Equations from: Hypersonic and
planetary entry flight mechanics.
By Vinh, Busemann, Culp.
Assumptions:
Constant angle of attack
The planet & Atmosphere does not rotate.
mass of vehicle is constant (no thrust)
Density varies exponentially with altitude, scale height of 49km density of kg/m^3.
Ignore Coriolis acceleration

6. Heat Flux Stagnation point Equations: Assumptions:
q:Convective Heat Flux
rn: Nose radius
V: Free stream velocity
Cp: Wall Specific heat coefficient
Tw:Wall Temperature
: Stefan Boltzmann const.
:emissivity
Assumptions:
Valid only for stagnation point
qr Ignored (valid only for LEO entry, I could not find an equation for this)

7. Comparison

8. Comparison cont’d

9. Future Additions to model
Add altitude and g-force constraints.
Use data to size actual heat shield.
Find acceptable wall temperatures

10. Related experience and course work
AAE 440, AAE415, AAE 590G, AAE 532, AAE 251
Program Knowledge:
MATLAB, FORTRAN77, IRONCAD, CMARC, JPL’s quick.