Characteristics of unsteady aerodynamic forces on an aeroelastic prism: A comparative study

Abstract

Aerodynamic forces on a slender prism are frequently estimated by conventional measurements using rigid models, thus the characteristics of unsteady aerodynamic forces inherent to an aeroelastic prism often remain unclear. Erected upon empirical results measured from aeroelastic, forced vibration and rigid models, this work supplies a holistic investigation on the characteristics of unsteady aerodynamic forces acting on a slender prism. First, local and generalized aerodynamic forces, unsteady pressures, corresponding power spectra, and Strouhal numbers on the three models are comparatively presented and discussed. Subsequently, wind-induced responses predicted by aerodynamic forces on the three models are drawn parallel to experimental results for comparison. The comparison indicates that the aerodynamic forces measured from aeroelastic and forced vibration models include the effect of structural motion, whereas those observed from a rigid model do not. Furthermore, the responses predicted by aerodynamic forces on an aeroelastic model are in close agreement with experimental results, whereas remarkable discrepancies are found for both forced vibration and rigid models. In addition, the hybrid aeroelastic-pressure balance (HAPB) test technique proves more effective in the measurement of aerodynamic forces than the forced vibration test technique. Ensuing investigation, this work not only advances our understanding on the characteristics of unsteady aerodynamic forces on an aeroelastic prism, but also ascertains the effectiveness of the aforementioned wind tunnel techniques.