The present study investigates influence of compressibility on separation induced transition in a low pressure turbine cascade using high fidelity direct numerical simulations of the T106A blade. Simulations are performed for inlet Mach numbers, Ms ranging from 0.15 to 0.35 at a fixed Reynolds number and high incidence, representative of off design LPT operation. A dispersion relation preserving numerical framework is employed to accurately capture instability waves, separation bubbles, and separation induced transition to turbulence. A comprehensive analysis is carried out using surface pressure and skin friction distributions, boundary layer integral parameters, spectral analyses, and budgets of compressible enstrophy. Increasing Ms systematically reduces streamwise extent of both leading edge and trailing edge separation bubbles and promotes earlier transition and reattachment, consistent with trends observed under increased free stream disturbances. Despite shorter separation regions, suction side momentum thickness at trailing edge increases from Ms = 0.15 to 0.35, indicating higher profile losses at elevated Ms. Spectral analyses demonstrate a redistribution of turbulent spatial and temporal scales, with energy injection occurring at progressively larger scales as Ms increases. Flow field visualizations reveal a transition pathway that shifts from two dimensional spanwise rolls and intermittent turbulent spots at low Ms to streak dominated, bypass like transition at higher Ms.
Numerical simulations of transition and long-term response of a wind turbine airfoil
FLOW, Department of Engineering Mechanics, KTH Royal Institute of Technology（KTH皇家理工学院工程力学系FLOW）；Department of Wind Energy, Technical University of Denmark, Risø Campus（丹麦技术大学风能系里斯厄校区）
Compressibility Driven Wake Transition and Hysteresis over Cargo Aircraft Aftbodies
Oklahoma State University（俄克拉荷马州立大学）；Indian Institute of Technology Kanpur（坎普尔印度理工学院）；Air Force Research Lab（空军研究实验室）；The Ohio State University（俄亥俄州立大学）
