Forebody shock control devices for drag and aero-heating reduction: A comprehensive survey with a practical perspective

The relative weight of convective and radiative wall heat transfer in liquid rocket engine thrust chambers is estimated by means of dedicated computational fluid dynamics tools. In particular, alth...

Convective and Radiative Wall Heat Transfer in Liquid Rocket Thrust Chambers

A numerical model is presented for evaluating thermal radiative transport in irregularly shaped axisymmetric enclosures containing a homogeneous, isotropically scattering medium. Based on the discrete exchange factor (DEF) method, exchange factors between arbitrarily oriented differential surface/volume ring elements are calculated using a simple approach. The present method is capable of addressing blockage effects produced by inner/outer obstructing bodies. The results obtained via the current method are found to be in excellent agreement with existing solutions to several cylindrical media benchmark problems. The solutions to several rocket-nozzle and plug-chamber geometries are presented for a host of geometric conditions and optical thicknesses.

Numerical model for radiative heat transfer analysis in arbitrarily shaped axisymmetric enclosures with gaseous media

In liquid rocket engines, wall heat transfer analyses are of primary importance for the thrust chamber design. Numerical investigations usually derive the convective heat flux from computational fl...

Numerical Investigation on Radiative Heat Loads in Liquid Rocket Thrust Chambers

USER MANUAL FOR RTE2002 Version 1 A COMPUTER CODE FOR THREE -DIMENSIONAL ROCKET THERMAL EVALUATION

Numerical models based on the discrete exchange factor (DEF) and the zonal methods for radiative analysis of rocket engines containing a gray radiatively participating medium have been developed These models implement a new technique for calculating the direct exchange factors to account for possible blockage by the nozzle throat Given the gas and surface temperature distributions, engine geometry, and radiative properties, the models compute the wall radiative heat fluxes at different axial positions The results of sample calculations for a typical rocket engine (engine 700 at NASA), which uses RP-1 (a kerosene-type propellant), are presented for a wide range of surface and gas properties It is found that heat transfer by radiation can reach up to 50% of that due to convection The maximum radiative heat flux is at the inner side of the engine, where the gas temperature is the highest Although the results of both models are in excellent agreement, the computation time of the DEF method is found to be much smaller Dimensionless radiative heat fluxes were calculated via a nonhomogeneous medium model using the DEF method

K. J. Hammad

Papers

Exchange factor model for radiative heat transfer analysis in rocket engines