Sensitivity analysis of extreme pressure loads to inflow disturbance parameters

Inflow disturbances affect the pressure loads on structures significantly. For the assessment of extreme loads, their sensitivity to variations in the inflow parameters must be quantified. In this work, the sensitivities of peak loads on a surface mounted prism to variations in incident gust parameters are determined. A parallel two-dimensional Navier- Stokes code is used to compute the pressure coefficients on the surfaces of the prism at Re = 1000. Latin Hypercube Sampling is applied to obtain the inflow parameters combinations. A non intrusive polynomial chaos expansion is then applied to determine the sensitivities. The results show that the gust destabilizes the separation shear layer, forces it to break down and moves it closer to the roof of the prism. As for the sensitivities, the results show that the front side wall and the first part of the roof are most sensitive to the streamwise amplitude of the disturbance while the top rear part and the leeward sides are most sensitive to the transverse amplitude of the disturbance.