Menter SST based detached eddy simulations (DES) is performed for transonic flow over an open cavity to study unsteady flow and acoustic fields.Sound pressure level (SPL) spectra and overall sound pressure level(OASPL) on surface of the cavity floor and the cavity back wall are computed.It shows that the second mode is dominant with the largest magnitude in SPL.

A weakly-compressible two-dimensional axisymmetric isentropic vortex model is employed to stimulate interactions between single vortex and single optical wavefront. For near-field aero-optics at low beam energies geometrical optics is adopted. Optical-path-difference of propagated distorted wavefront is computed. It is confirmed that transform of beam wavefront is accelerated as beam passing through the vortex with low density. Single vortex defocuses the beam. Computation on COIL indicates that strength of vortex has strong effect on Strehl rate.