Drag and Flutter Characteristics of Loop Membranes

Abstract

. The loops were tested for a variety of aspect ratios, from 3.3 to 30,three planform areas, and twomounting methods. Results are presented for the drag coefficient and for the flutter characteristics. We prove that with a low aspect ratio the loops form a teardrop shape andtheir flutter modeisasinusoidal-like oscillation.Furthermore,the dragcoefficientdecreaseswiththeincreasing wind speed, but it depends strongly on the aspect ratio and the planform area. Empirical correlations for the drag coefficient are polynomial equations. Nomenclature A = planform area, m 2 CD = drag coefficient based on the planform area (single side area) c1, c2 = coefficients in Eq. (1) Re = Reynolds number based on loop length U = freestream velocity, m=s � = loop thickness, mm