MICROPHONE PROBE FOR ACOUSTIC MEASUREMENT IN TURBULENT FLOW

摘要

Abstract of the DisclosureA microphone probe for acoustic measurementin turbulent flow. The probe includes a tube having aclosed end facing upstream with respect to the direc-tion of sound propagation, and a microphone is locatedin the downstream end of the tube. The tube is provid-ed with a plurality of small ports, or alternately aslit, that extend a substantial portion of the lengthof the tube and an acoustically resistive material isstretched across the ports and clamped to the tube. Inone form of the invention, the side edges of thematerial are connected to rigid bars and the bars aredrawn together by a plurality of threaded fasteners tostretch the material over the ports. The threadedadjustment of the fasteners provides a means for vary-ing the acoustical resistance of the material. In asecond form of the invention, the bars to which theside edges of the material are attached, are clampedtogether by spring clips.