Gust Induced Aerodynamic Force Prediction on a Transport Wing Using Quasi-Steady Approximation

Abstract

The atmospheric wind turbulence over a specified time period has a strong influence on the airplane performance characteristics. Forecasting of this unsteady aerodynamic phenomenon is complex one for designing the control systems to ensure the structural safety. A novel approach is developed to assess the influence of a gust structure on the aerodynamic coefficients of an airplane. The load factor enhancement because of the discrete gust is also quantified to ensure the safety margin. The Kussner’s function is used to determine the time varying increment of gust-dependent lift produced on an airplane wing entering a sharp-edged gust. A most general gust shape is assumed for the present study with quasi-steady approximation. The turbulent viscosity across the chord wise positions are quantified to calculate the velocity fluctuations because of eddies. Determining the gust influence on the fundamental lift and drag characteristics of a commercial airplane is focused in the present investigation. It is accomplished with the help of Wagner’s function in the time domain for the gust response-dependent lift. The outcome of the numerical simulation process is fully verified using the theoretical and experimental results. Solution convergence is attained for a range of input conditions and it shows that the proposed methodology is competent to assess the gust response for various airplane systems design.