Parametric Study for Directional Stability of Tumbling Plates by Wind Tunnel Testing

Abstract

The tumbling phenomenon is considered to be an important phenomenon for aircraft flight safety because of the possibility of falling objects from the aircraft reaching far away or for knowing the behavior of falling roof tiles blown off by strong winds. Therefore, many tests to measure the force act on the tumbling plate in wind tunnel have been conducted. The authors have been studying the directional stability of the tumbling plate [9], which has a great effect on the reach of falling objects, and have proposed a non-contact measurement method wind tunnel test method from the viewpoint of dynamic balance which can acquire the force without force sensors [12]. Here, we call "towing wind tunnel test method". In this paper, for the evaluation of the directional stability of the tumbling plate, we parametrically changed the planar configuration of the tumbling flat plate and measured the acting force in wind tunnel using this towing wind tunnel test method. As a result, the relationship between the shape of the tumbling plate and the conditions for directional instability was clarified.