Application of PVDF foils for the measurements of unsteady pressures on wind tunnel models for the prediction of aircraft vibrations

Abstract

An experimental investigation of unsteady pressures on military aircraft wind tunnel models has been performed using Polyvinylidenfluorid (PVDF) sensors. The unsteady pressures from the wind tunnel measurements are a prerequisite for the prediction of dynamic loads and vibrations during the development and design of new fighter aircraft structures. In the past the wind tunnel unsteady pressure measurements had been performed using wind tunnel models equipped by Kulite pressure sensors. This technique resulted in very high cost wind tunnel models. In contrast the application of the PVDF foil Smart Sensor & Signal Processing Technology would lead to improvements through the application of an affordable test technique which could be also applied in flight with the benefit of more accurate and locally detailed pressure information. The present investigation includes the measurement of unsteady pressures with PVDF foils on a wind tunnel model of a trainer aircraft configuration in the high speed transonic wind tunnel of the NLR Amsterdam. The investigated Mach numbers were M0.5, M0.7 and M0.9 and the incidence range was 0 to 45 degrees. The results of the experiments are discussed using the analysed time histories and power spectral densities of the stochastic unsteady pressure and comparisons to results using direct unsteady pressure measurements. Main aspect is the evaluation and validation with respect to technical industrial applicability of PVDF foils. ©2010 Society for Experimental Mechanics Inc.