Acoustic measurements are now possible, in the test sections of our S1MA (for high speeds), and CEPRA19 (for lowspeed) wind tunnels... The S1MA wind tunnel can be fitted with a low-speed anechoic test section (fitted with liners), which allows acoustic measurements to be made at lowspeeds up to Mach 0 30. The far-field instrumentation consists of two rows of 18 microphones, each set in the test section walls, and covered with wiremesh
Four flights have already been carried out at the Saint-Yan airfield in Burgundy, each lasting about 20 minutes, at lowspeed, and with or without an experimental rocket payload. These flights confirmed the good performance of Eole, during take-off and landing for instance
All of this was done at flow velocities that are quite unusual for this wind tunnel, namely at very lowspeeds. This opportunity was made possible within the framework of the European Project FP7 (European Strategic Wind tunnels Improved Research Potential)