RE -ENTRY OF SPACE
VECHICLE
Dm . vinaya
20E31A2106
CONTENT
1.Introduction
2.aerodynamic heating
3.problems of over heating
4.the diversion of heating by shock wave
5.history
6.modelling of re entry vehicle
7.thermal protective system
INTRODUCTION
• Re entry refers to the return of a spacecraft into earth
atmosphere
• The blanket of relatively dense gas surrounding earth
is useful as a braking ,force resulting from
aerodynamic drag
• Re entry vehicle is a spacecraft that travel through
space and re enter the atmosphere of a planet, and
most of the time does not have an engine
Aerodynamic heating
•Re entry vehicle has to survive
aerodynamic heat
•Reason :12000deg F heat will be
vaporize the vehicle
Re entry of space vehicle
PROBLEMS OF OVERHEATING OF THE VEHICLE
CAN BE REDUCED BY
• Basically reduced by below mentioned ways they are
• 1.The diversion of heat by shock wave
• 2.By radiating heat away from the hot surface of the
vehicle
THE DIVERSION OF HEAT BY STRONG SHOCK
WAVE
• By molecular interaction
• Phenomenon occurs in the way of
1.air molecules strike the forward surface
2.then, molecules bounce back
3.rebounding molecules collide with oncoming molecules
• It can lead to prevent the heat transfer through direct impact
history
• H .Julian alley and Alfred eggers, presented
blunt body re entry techniques in1958
Conclusion derived as
• spacecraft with blunt nose produces the strongest
shock wave
Shape determination and modelling of
sharp edge re entry vehicle
• High L/D ratio leads to peak deceleration
• High speed global passenger transport
• Control over the vehicle was increased
THERMAL PROTECTIVE SYSTEM USING
ABLATIVE MATERIALS
• An ablative composite is a type of composites, which
are used to protect certain structures or equipment
from intense heat environment
• Ablation is the process of combustion where surface
material decompose and protect the base material
• During the re entry ,the surface of charring
ablator in a vehicle suffer severe aerodynamic
heating
The charring ablator is divided into four layers
namely virgin layer ,
the pyrolysis layer , the char layer and the
ablation layer
THERMAL PROTECTIVE SYSTEM
Thank you