Abstract
In order to reduce the noise level in super sonic wind tunnel, a laminarization of the boundary layer in wind tunnel constraction is essential. Detailed measurements were conducted in the wind tunnel equipped at National Aerospace Laboratory (NAL) and Institute of fluid Science Tohoku Univ (IFS). Spanwise wavenumber of the disturbance of some streamwise potitions are computed by using the maximum entropy method (MEM). Results show that downstream spanwise wavenumber generated via Gortler vortices is smaller than upstream one.