To study the aero-optical effect of Laguerre-Gaussian(LG)beams passing through the flow field around a turret,we solve parabolic beam equations of complex amplitude by second-order compact differences and fourthorder Runge-Kutta integration.In the same flow field,light intensity distributions of LG beams with different topological charges,optical path differences(OPD)of the same beam calculated by numerical simulations and integrated along optical path are both compared.Strehl ratio(SR)and imaging displacem...