Gust response prediction with CFD-based reduced order modeling

raditional gust responses are mainly analyzed based on linearaerodynamic load calculations in frequency-domain, which is unsuitable forand the viscous and transonic flows. Since gust response for aircraft designneeds to be calculated for the many gust cases with various frequencies andshapes, direct CFD-based gust response predictions are huge time-consuming.In the paper, a new gust response method is developed based on CFD methodcoupled with ARMA reduced order model. CFD is only used once for a specialgust to identify coefficients of ARMA model. The computational efficiency ofgust response analysis for any shaped gust can be improved significantlybased on the determined ARMA model compared with the direct CFD method. Tovalidate the new developed method, first, for NACA0012 airfoil at Machnumber of 0.11, the gust responses are analyzed through the comparisons ofthe results of CFD, ARMA model and an early incompressible analyticresolution. Then, the method is also testified to be valid for transonicflows.