Jul19: Seminar on Passive Aerothermodynamic Flow Control Methods for Lifting Body Configurations in Hypersonic Flow

Dr. Shashank Khurana, PhD, University of Tokyo, would be presenting a seminar in the department as per the following schedule.

Speaker:   Dr. Shashank Khurana, PhD, University of Tokyo
Title: Passive Aerothermodynamic Flow Control Methods for Lifting Body Configurations in Hypersonic Flow
Date  :      Friday, July 19, 2013
Time  :      03:30 PM
Venue :    AE seminar room

Tea would be served at 3:15PM.

Abstract

The increased drag and convective heating associated with flow at hypersonic speeds have a significant impact on the design of vehicles. Passive flow control techniques of using a forward-facing aerospike and breathing blunt nose concept were chosen as the potential candidates for the current investigation. A forward-facing spike attached at the nose of a blunt-body has been established as a means to favorably modify the flow field with a significant influence on the aerodynamic characteristics in hypersonic flow and can be regarded as a prospective option for drag reduction and increase of (lift/drag)-ratio of blunt nosed flying vehicles. The various parameters to be considered includes spike length, shape, spike-nose configuration and angle of attack. Breathing blunt nose (BBN) concept study, proposed for drag reduction, by bleeding the air from nose and discharging it at the base, in an attempt to increase the pressure at the base of the body, hence reducing the contribution from base drag against the direction of motion. However, the studies have been conducted only on simple axisymmetric geometries and not on representative lifting body shapes. These concepts have been studied on simple basic geometries only, therefore it has been investigated for practical feasibility and application on lifting body configurations with the help of wind tunnel experiments carried out at Mach 7 on a 70° swept-back lifting body shape forming a delta shape, with axisymmetric nose, and using shallow water channel visualization technique. Flow visualization was carried out using the schlieren technique. Measurements made at freestream Mach number 7 with six-component force balance system revealed a large increase in the Lift/Drag Ratio and marginal increase in pitching moment coefficient compared to no-spike case, together with overall reduction in the nose surface area exposed to heating for aerospikes, and significant drag reduction for BBN case, proving worthy at high angles of attack; thereby indicating their practical feasibility for eventual future applications to spacecrafts.  

About the Speaker

Dr. Shashank Khurana completed his Ph.D. in Advanced Energy from the University of Tokyo in June 2013. He worked on analyzing the effectiveness of employing passive flow control techniques to high-speed lifting-body type commercial vehicle applications, and thereby augmenting the aerothermodynamic efficiency for their safe, economic and reliable use. He completed his Masters’ in Aerospace Propulsion from I.I.T.- Bombay, where he focused on the optimization studies for use of passive thermal protection systems, on prospective hypersonic vehicles, in tandem. He obtained is Bachelors’ in Mechanical Engineering from Devi Ahilya University, Indore. His research interests include Hypersonics, Experimental Fluid Dynamics with Flow Control applications in high-speed and low-speed flow, Flow Visualization and Heat Transfer.