COMPARATIVE ACOUSTICAL CHARACTERIZATION OF SAILPLANE INTERIORS Jurica Ivošević1, Dubravko Miljković2, Tino Bucak1 1University of Zagreb, Faculty of Transport and Traffic Sciences, Department of Aeronautics, Vukelićeva 4, Zagreb, Croatia; 2HEP Zagreb, Croatia
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[email protected] Abstract: Aircraft interior noise of small engine powered aircraft and their comparison have been investigated by many researchers. This paper deals with a glider aircraft that, after being launched by towing aircraft, continues an autonomous, non-powered soaring flight. The interior noise is predominantly generated aerodynamically by wind slipstream during progressive flight. A number of interior noise measurements have been undertaken on two different types of glider aircraft, Schleicher K7 Rhönadler and Blanik L-13, at different phases of flight with various speeds and wing control surface configurations and some of the results will be presented and discussed. Key words: sailplane, glider, interior, acoustics, noise 1. INTRODUCTION 1.1. Sources of sailplane noise This paper focuses on the comparative acoustical The noise of small engine powered aircraft usually characterization of the interiors of two different types of consists of two major components: powerplant noise glider aircraft, Schleicher K7 Rhönadler and Blanik (engine, exhaust and propeller noise) and aerodynamic L-13, both being used for flight training and operated by (airframe) noise, [1]. In addition to the airframe noise and Aeroklub Zagreb. This contribution to the overall noise structure borne noise present during autonomous flight, image of sailplanes interior should be known, as those noise in a sailplane during a towing phase originates also findings can be used to control and minimize the noise from the towing aircraft (engine, propeller and exhaust effects on crew.