Maksim V. Ustinov
DOI Number XXX-YYY-ZZZ
Conference Number HiSST 2018_19601030
Amplitude method describing influence of surface roughness and free-stream turbulence level on laminar-turbulent transition caused by cross-flow instability is developed and tested. In contrast to e^N method it is based on computation of amplitudes of steady and non-steady cross-flow instability modes in the boundary layer. Initial amplitudes of these modes were found from solution of receptivity problem to surface roughness and free-stream turbulence respectively. Subsequent evolution of these disturbances is evaluated by means of non-linear PSE-method modified for perturbations with random phases. Point where sum of amplitudes of steady and non-steady modes reaches threshold value is treated as transition location. Method developed was verified using available experimental data obtained in low-speed wind tunnels and applied to transition prediction at the swept wing for supersonic flow velocity.