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Proceedings of the 24th National and 2nd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2017)

ISBN Онлайн: 978-1-56700-478-6


DOI: 10.1615/IHMTC-2017.1410
pages 1013-1018

SH Gowtham Gudimella
Scientist-C, DRDL-Hyderabad

PK Sinha
Scientist-G, DRDL-Hyderabad

R Krishna Mohan Rao
Scientist-G, DRDL-Hyderabad


Flight vehicles used in space/defense applications typically have re-entry configurations in the form of blunt cones which are subjected to severe aerodynamic heating during re-entry phase of the trajectory. At the beginning of re-entry, wall temperature will be lower and subsequently gets heated to very high temperature due to high heat fluxes which may result in mission failure. Cavities formed during stage separation are subjected to high heat flux/ high temperature whose measurements through experiments is a challenging task. The prohibitive costs involved in performing even scaled down laboratory experiments and absence of analytical solutions adds to the complexity thereby making CFD a viable alternative. However, near exponential growth in the numbercrunching abilities of computers enables quick solutions of moderate accuracy. Thus use of CFD in estimating the heat flux at re-entry conditions is the state-of-art solution which reduces lead time, cost and also gives better insight into various parameters for analysis. In this paper, heat flux is estimated using CFD on a generic re-entry configuration having base cavity which is formed due to the separation of inter-stage motor from full flight vehicle configuration.
Re-entry flight conditions are identified for estimating the heat flux from ρV3 plots of different trajectories. They are (1) M=5, Altitude 3 Km, (2) M=8, Altitude 7 Km, (3) M=13, Altitude 13 Km and (4) M=16, Altitude 20 Km. For each condition four different wall temperatures (Tw) 500 K, 1000 K, 1500K and 2000 K are considered. CFD simulations have been carried out using ANSYS FLUENT code in N-S mode with k-ω SST turbulent model. 2-D Axi-symmetric half body structured grid of size 0.12 million using GAMBIT is generated capturing base cavity geometry. Variation of heat flux along the cavity wall at all four conditions is studied. This data is very much useful for the design of thermal protection system of payload.