Local Algebraic Transition Model With Crossflow Correlations and Compressibility Corrections

A new formulation of a local correlation-based algebraic transition model coupled with the Spalart--Allmaras turbulence model is presented. The model is based on the Langtry--Menter empirical correlations for natural and bypass transition as well as helicity-based crossflow correlations. A local vorticity limiter is developed and implemented to improve the numerical stability and predictive capability for separation-induced transition. Compressibility corrections are also included to extend the empirical correlations to transonic flight conditions. Two- and three-dimensional subsonic and transonic test cases demonstrate the model's ability to accurately and efficiently predict transition locations and aerodynamic coefficients, showing good agreement with both experimental data and a transport-equation-based transition model. The absence of additional transport equations for transition prediction makes the algebraic model a simple low-cost alternative in natural laminar flow wing design applications.