A numerical study of combined convective and radiative heat transfer in a rocket engine combustion chamber
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Authors
Savur, Mehmet Koray
Subjects
Radiative Heat Transfer
Rocket Engine
Combustion Chamber
RADCAL
TEP
CFD-ACE
non-gray gas
spectral transmissivity
absorption coefficient
Rocket Engine
Combustion Chamber
RADCAL
TEP
CFD-ACE
non-gray gas
spectral transmissivity
absorption coefficient
Advisors
Gopinath, Ashok
Date of Issue
2002-12
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
Abstract
A numerical study was conducted to predict the combined convective and radiative heat transfer rates on the walls of a small aspect ratio cylinder representative of the scaled model of arocket engine combustion chamber. A high-temperature, high-pressure environment was simulated in the cylinder, with gas velocities at low subsonic levels typical of the conditions leading to the entrance of the nozzle section of a rocket engine. The composition of the gases in the cylinder was determined from the TEP program for the burning of rocket fuel at typical values of the O/Fratio. The thrust of the study was to determine the radiative contribution to the heat transfer rate from the hot participating chamber gases to the cooler wall. The calculations were carried out using the commercial CFD package CFDACE, and were first benchmarked against known results in the literature for the simpler case of gray chamber walls and a gray participating medium. Thenon-gray computations were subsequently carried out using gas absorption coefficient values obtained from the exponential wide band model with the help of the fire-modeling program, RADCAL.The effect of different chamber wall temperatures and gas compositions were examined. The main findings of the study are that the radiative contributions at the high gas temperatures being considered are comparable to the convective values, and strongly spectral in nature. In addition these radiative fluxes were found to be least sensitive to the wall temperature and chamber pressure in the range considered. Furthermore, this radiative contribution reaches a maximum at aunique optimal optical thickness of the gas that lies within the extremes of the optically thin and thick limiting cases.
Type
Thesis
Description
Series/Report No
Department
Mechanical
Organization
Identifiers
NPS Report Number
Sponsors
Funder
Format
xiv, 83 p. : ill. (some col.) ;
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
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Copyright is reserved by the copyright owner.