RESULTS OF TWO FREE-FALL EXPERIMENTS ON FLU_TER OF THIN UNSWEPT WINGS IN THE TRANSONIC SPEED RANGE 1

Flutter data in the transonic speed range for four nearly identical, thin, unswept wings have been obtained by the bomb-drop method. Two wings fluttered at a Mach number of 0.85, one wing fluttered at a Mach number of 1.03, and the other wing fluttered at a Mach number of 1.07. The experimental flutter speeds were compared with values calculated by using a method of analysis which includes the effect of mode shape and is based on two-dimensional flow. The calculations were made for Mach numbers ranging from 0 to 1.43, including a Mach number of 1.0. The experimental flutter speeds, in general, exceeded the calculated values. There is an indication that the critical flutter region is moved to a higher Mach number range when thin wings are used