Akihito Iwasaki

Aerodynamic/Aeroacoustic testing in Anechoic Closed Test Sections of Low-speed Wind Tunnels

This paper describes new anechoic closed test sections in Japan Aerospace Exploration Agency (JAXA) and Virginia Tech (VT) not only for an aeroacoustic but also for an aerodynamic testing ability in Low-speed wind tunnels. The anechoic closed test section with Kevlar wall is an innovative concept and had been originally developed at VT. It was later applied to JAXA’s 2m x 2m wind tunnel. By using a high-lift device model, the JAXAs new test section was evaluated and validated acoustically by comparing to VT anechoic test results. Moreover, the aerodynamic characteristics in the new test section were also evaluated by comparing to results of the same model in JAXAs closed hard-wall test section. New wall interference correction procedure is proposed for the Kevlar wall test section, and it showed very good agreement with well-known corrected hard-wall results. This anechoic test section is useful and a promising tool for both aerodynamic and aeroacoustic testing.

Experimental Studies of a 70-Degree Delta Wing with Vortex Flaps

Force, surface pressure, and flowfield measurements were made on a 0.5-m root chord, 70-deg delta wing model with leading-edge vortex flaps at the National Aerospace Laboratory, Japan. The main objective of the experiment is to investigate the effect of the wing sweepback angle upon the vortex flap performance. Improvements in the lift/drag ratio were observed in a 70-deg delta wing by deflecting the tapered vortex flaps.