THREE- DIMENSIONAL THERMAL ANALYSIS OF REGENERATIVE COOLED AEROSPIKE NOZZLE

GROUP MEMBERS:

1. AKHIL C AJANTH2. FAISAL M M 3. JANE JOSEPH

GUIDED BY:

Mr. Manikandan

ABSTRACT• Aerospike nozzle is an advanced nozzle design of liquid rockets in which a truncated spike is used, which demonstrate altitude adaptation up to their geometrical area ratio.

• Regenerative cooling is adopted in the nozzle to optimize the fuel consumption and cooling technique.

• This project focuses on cooling technique which eliminates gas generator in truncated aero spike nozzle by creating secondary flow using heated fuel after active cooling.

INTRODUCTION• Aerospike nozzles offers high altitude compensation, thrust vectoring capability and reduced circulation effect

• Regenerative cooling refers to the use of the liquid fuel or oxidizer itself to provide the cooling.

• The design of coolant passages in regenerative cooled thrust chambers is critical to the operation and safety of a rocket engine system.

EXISTING TECHNOLOGY

• Cooling is presently done using nitrous oxide(N2O)

• For a truncated aerospike nozzle, a gas generator is used to eliminate turbulence.

OBJECTIVES

• To implement regenerative cooling on aerospike nozzle

• To perform 3-d thermal analysis on the nozzle to optimize the cooling technique

LITERATURE SURVEY

• Patrick Lemieux of California Polytechnic State University, San Luis Obispo, CA 93407, United States has done a paper on “Nitrous oxide cooling in hybrid rocket nozzles “.The paper presents the result of a recent development project focused on reducing throat ablation in hybrid rocket motor nozzles. • Daniel Joseph Grieb on February 2012 submitted A Thesis to the Faculty of California Polytechnic State University, San Luis Obispo named “Design and Analysis of a Reusable N2O-Cooled Aerospike Nozzle for Lab scale Hybrid Rocket Motor Testing”.

Sarah L. Kulhanek Submitted to the graduate degree program in Aerospace Engineering and the Graduate Faculty of the University of Kansas named “ Design, Analysis, and Simulation of Rocket Propulsion System”.

A milestone was achieved when a joint academic/industry team from California State University, Long Beach (CSULB) and Garvey Spacecraft Corporation successfully conducted a flight test of a liquid-propellant powered aerospike engine in the Mojave Desert on September 20, 2003.

NOZZLE DIMENSIONS

NOZZLE DATA

Thrust exit area ratio (Aei/At) 3.5

Aerospike expansion ratio(Ae/At) 58

Radius of lip of cowl 54.7m

Truncation as percentage of total aerospike length 26.30%

Distance of throat to end of thruster 7.241m

Distance from end of thruster to end of ramp 64.059m

Aerospike length from origin (L nozzle) 71.3m

Reference : http://aerorocket.com/MOC/MOC.html

SPECIFICATIONS (XRS-2200)

XRS-2200 Engine 5K ft Vacuum

Thrust, lbf 204,420 266,230

Specific Impulse, sec 339 436.5

Propellants Oxygen, Hydrogen

Mixture Ratio (O/H) 5.5

Chamber Pressure, psi 857

Cycle Gas Generator

REGENERATIVE COOLING IN AEROSPIKE NOZZLE• maximizing the life and durability of rocket

components.

• focus on using the fuel to cool engine components

• design of coolant passages in regeneratively cooled thrust chambers is critical to the operation and safety of a rocket engine system.

• Designing a coolant passage is a complex thermal and hydraulic problem

ADVANTAGES

• Extra coolant can be avoided.• Efficient cooling is obtained• the fuel when subjected to high temperature, it vapourises and this gas can be used to avoid turbulence in truncated nozzle.• Additional thrust is obtained since the fuel used as coolant is finally expanded to add up thrust• Gas generator can be eliminated

CURRENT STATUS•Detailed study of aerospike nozzle is done •Study of regenerative cooling in aerospike nozzle is carried out

•Dimensions of aerospike nozzle is obtained

PLAN FOR PHASE TWO

Determining an optimum geometry for the hot side flow path upstream of the throat. analyze if there is any best suited shape that could minimize the amount of cooling capacity that the aerospike would require

• to perform 3D thermal analysis on regenerative cooled aerospike nozzle which includes:

modeling the flow of hot gases using FLUENT .This model is used to predict heat transfer coefficients on the surface of aerospike

Survey the normal heat loads on the tested aerospike nozzle.

Determining heat load is important because it can be used to calculate amount of coolant mass flow required to maintain the desired temperature over the surface of aerospike

Design and Analysis of coolant process path(calculate exact process path of fuel)and to suggest the best one.

   

CONCLUSION

Details of aerospike nozzle and its historical background have been collected

different cooling methods existing in aerospike nozzle are studied.

Cooling is presently done using nitrous oxide (N2O)

new concept for eliminating the gas generator in a truncated aero spike nozzle by using fuel as a coolant is suggested.

To be continued…