Theoretical and experimental investigations of wall adaptation control in wind tunnel and hybrid wind tunnel testing

✍ Scribed by Th. Hottner

• Publisher: Springer
• Year: 1995
• Tongue: English
• Weight: 650 KB
• Volume: 19
• Category: Article
• ISSN: 0723-4864
• DOI: 10.1007/bf00196471

✦ Synopsis

The hybrid wind tunnel principle is an economical alternative to classical wind tunnels. Wall adaptation tests are reported which are performed in a small scale arrangement duplicating original kinematic relations. A new method for controlling the quality of wall adaptation is presented which is based on the pressure distribution at the rigid wall. This procedure may also be applied for wall adaptation in conventional wind tunnel technique.

List of symbols cp pressure coefficient ( = (p--po~)lq~ ~ --2ulu~)

d diameter h height of test section k constant for cross flow pressure drop through perforated wall 1 length Ma Mach number p pressure q dynamicpressure(=2PMa2 ) r radius s gap width t time u, v disturbance velocity w flow velocity x coordinate in flow direction fl Prandtl factor boundary layer thickness ~c ratio of specific heats ~b adaptation coefficient-c~ (C~)r (subcritical flow)