Investigation of nozzle contours in the CSIR supersonic wind tunnel

Abstract

The existing nozzle contour profiles of the CSIR’s supersonic or High Speed Wind Tunnel (HSWT) produce weak waves in the test section region, which effectively degrades the air flow quality in the test section. This paper describes a calculation method developed to improve the flow quality in the test section region subject to the HSWT’s limitations. The wind tunnel geometry and constraints were employed in accordance with the Sivells’ nozzle design method and the method of characteristics technique to design the nozzle profiles for the full supersonic Mach number range 1=M=4.5 of the facility. Automatic computation was used for the profile design and a computational method analysed the test section flow characteristics. A boundary layer correction was applied to the profiles to account for the reduction in Mach number due to viscous effects. The method used, achieved uniform and shock-free test section flow, such that the Mach number distribution and flow angularity were within the acceptable quality limits of the HSWT.