1. P M V Subbarao Professor Mechanical Engineering Department
Analysis of Missiles
P M V Subbarao
Professor
Mechanical Engineering Department
Simple Propulsion Systems but not for Humans!!!

2. Hypersonic Flyers : Comprehensive Mechanism of Intake Air Control= 1 + g - ( ) 2 x s i b æ è ç ö ø ÷ M y = n s i b - q ( )

3. Oblique Shock Wave Angle Chart
max
curve
Mx=5.0
Mx=3.0
Mx=1.5
Mx=4.0
Mx=2.5
Mx=2.0

4. Performance of An Adiabatic Oblique Shocky x = 1 + 2 g ( ) M n - T y x = 1 + 2 g ( ) M n - é ë ê ù û ú
But
Pressure Recovery Factor or Total Pressure Ratio for the oblique shock :

5. Performance of An Adiabatic Oblique Shock
Across a Shock
Available Resource
Pressure Recovery Factor or Total Pressure Ratio for the oblique shock :

6. Performances of NS & OS
The total pressure recovery of a normal shock rapidly deteriorates beyond Mach ~ 1.6.
90% total pressure recovery is achieved at 1.6.

7. Simplest Reversible Inlet of A Missiles
Oblique Shock
Normal Shock
A single compression ram inlet involves one oblique shock and one normal shock.

8. Inlet with Multiple External Compressions
A double compression ram inlet involves two oblique shocks and one normal shock.

9. Multiple External compressions Inlets

10. Performance Enhancement of External Compressions to Inlet

11. Special Designs of Center Bodies
If there are multiple shocks: Mx
My1
My2
My3 q

12. The Ancient Flyers : Ramjets (Asthras)
Only three operating components:
A central Body
intake (diffuser)
burner (combustion chamber);
nozzle

13. Ramjets - Basic Operating Features
External shock decelerate ambient air entering the flyer.
This Air is further decelerated in intake (diffuser).
The pressure rises due to ram effect.
Known as ram pressure and significant at supersonic speeds.
A ramjet therefore needs no machines or engine to increase the pressure.
Simplifies the design and reducing the cost.
Greatest disadvantage is that it has to be accelerated up to very high speed before it produces any useful thrust.
Also complicated supersonic intake required to avoid shock losses.

14. The Asthra : Modern Models

15. Frictionless Flow through Constant area Pipe with Heat Transfer
exit
inlet
Momentum equation gives
Integrating from inlet to exit: