Authors: Ashish Narayan; S. Narayanan; Rakesh Kumar; Chintoo Sudhiesh Kumar; Gopalan Jagadeesh
Addresses: Indian Institute of Technology (Indian School of Mines), Dhanbad, India; Chaibasa Engineering College, Chaibasa, India ' Indian Institute of Technology (Indian School of Mines), Dhanbad, India ' Indian Institute of Technology (Indian School of Mines), Dhanbad, India ' Super-Wave Technology Private Limited, Bangalore, India ' Indian Institute of Science, Bangalore, India
Abstract: The present study investigates the aerodynamic characteristics of spherically blunted nose cone at a hypersonic Mach number of 5.8, numerically. The studies are conducted for different combinations of bluntness ratios and semi-cone angles, at zero angle of attack, in order to ascertain the nose cone parameters which provide minimum aerodynamic drag coefficient. The velocity vector shows the flow deceleration near the nose, re-acceleration through the sides as well the formation of recirculation zones. The structure of bow shock formed ahead of the nose as well as shock detachment distance is depicted by the Mach number contours. It is observed that the shock detachment distance follows linearly increasing behaviour with increase in bluntness ratios for all semi-cone angles studied. An empirical expression is developed for the shock detachment distance using the regression analysis, which reveals that it is mainly a function of bluntness ratio. It is observed that the aerodynamics drag coefficient attains a minimum value for smaller, bluntness ratios and semi-angle. Further, the aerodynamic drag coefficient is observed to be a strong function of bluntness ratios for smaller semi-cone angles.
Keywords: spherically blunted nose cone; hypersonic flow; bluntness ratio; semi-cone angle; shock detachment distance; aerodynamic drag coefficient.
Progress in Computational Fluid Dynamics, An International Journal, 2020 Vol.20 No.2, pp.105 - 123
Received: 12 Sep 2018
Accepted: 27 Jun 2019
Published online: 26 Mar 2020 *