• Advances in aircraft and spacecraft science
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• v.4 no.4
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• pp.487-501
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• 2017

The main purpose of the paper is to analyze effect of geometrical parameters of the reentry capsules such as radius of the spherical cap, shoulder radius, back shell inclination angle and overall length on the flow field characteristics. The numerical simulation with viscous flow past ARD (Atmospheric Reentry Demonstrator), Soyuz (Russian) and OREX (Orbital Reentry EXperimental) reentry capsules for freestream Mach numbers range of 2.0-5.0 is carried out by solving time-dependent, axisymmetric, compressible laminar Navier-Stokes equations. These reentry capsules appear as bell, head light and saucer in shape. The flow field features around the reentry capsules such as bow shock wave, sonic line, expansion fan and recirculating flow region are well captured by the present numerical simulations. A low pressure is observed immediately downstream of the base region of the capsule which can be attributed to fill-up in the growing space between the shock wave and the reentry module. The back shell angle and the radius of the shoulder over the capsule are having a significant effect on the wall pressure distribution. The effects of geometrical parameters of the reentry capsules will useful input for the calculation of ballistic coefficient of the reentry module.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.6
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• pp.414-421
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• 2019

In this paper, thermomechanical coupled analysis of carbon/phenolic composites structures in reentry environment was performed. The interface of thermomechanical coupled analysis was constructed using commercial software. The governing equations of temperature and displacement fields were considered to simulate change of physical behavior due to pyrolysis and ablation effects. The results of thermomechanical coupled analysis were compared with the results of ablation test using arc-heated wind tunnel. Also, the structural stability of reentry capsule was analyzed using the analysis interface. The excellent ablation characteristics and thermal protection effects of the carbon/phenolic composites were confirmed and the constructed analysis interface can be effectively used to perform thermal protection system design.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.23-32
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• 2016

Various studies have been conducted for drag reduction of a high-speed vehicle by injecting counterflow jet from its nose cone. In this study, in order to obtain baseline data and key parameters for drag reduction method, the counterflow jet study of the USA is reviewed and summarized. The nose cone shapes of each study are hemisphere cylinder, truncated cone, and reentry capsule, and their test conditions are summarized accordingly. Key parameters for drag reduction are jet mach number, mass flow rate, and pressure ratio. Even though drag reduction effects show various results according to given test conditions, it is found that the drag reduction effect reaches up to 40~50%.