Two new two-equation eddy-viscosity turbulence models are introduced in this paper. The first model, the baseline (BSL) model, combines the Wilcox $ k-\omega $ model for inner boundary layer regions with the standard $ k-\epsilon $ model for outer regions and free shear flows. It avoids the strong freestream sensitivity of the original $ k-\omega $ model. The second model, the shear-stress transport (SST) model, improves performance by accounting for the transport of the principal turbulent shear stress, leading to major improvements in adverse pressure gradient flow predictions. The paper discusses the challenges of two-equation models in accurately predicting adverse pressure gradient flows and the lack of standardized criteria for evaluating model improvements. It emphasizes the importance of empirical testing over theoretical assumptions. The BSL model uses a blending function to switch between the $ k-\omega $ and $ k-\epsilon $ models, ensuring numerical stability and accuracy. The SST model further refines the eddy viscosity formulation to account for turbulent shear stress transport. The models are tested against various flow cases, including flat plate boundary layers, free shear layers, adverse pressure gradient flows, backward-facing step flows, and NACA 4412 airfoil flows. The SST model shows superior performance in adverse pressure gradient flows, accurately predicting separation and viscous-inviscid interactions. The BSL model performs similarly to the original $ k-\omega $ model but avoids freestream sensitivity. The paper concludes that the new models are more robust and accurate, with the SST model being particularly effective for aerodynamic applications. They require more programming effort but offer improved stability and performance. The models are tested on various grids and show grid independence. The authors emphasize the importance of empirical validation and the need for rigorous testing of turbulence models.Two new two-equation eddy-viscosity turbulence models are introduced in this paper. The first model, the baseline (BSL) model, combines the Wilcox $ k-\omega $ model for inner boundary layer regions with the standard $ k-\epsilon $ model for outer regions and free shear flows. It avoids the strong freestream sensitivity of the original $ k-\omega $ model. The second model, the shear-stress transport (SST) model, improves performance by accounting for the transport of the principal turbulent shear stress, leading to major improvements in adverse pressure gradient flow predictions. The paper discusses the challenges of two-equation models in accurately predicting adverse pressure gradient flows and the lack of standardized criteria for evaluating model improvements. It emphasizes the importance of empirical testing over theoretical assumptions. The BSL model uses a blending function to switch between the $ k-\omega $ and $ k-\epsilon $ models, ensuring numerical stability and accuracy. The SST model further refines the eddy viscosity formulation to account for turbulent shear stress transport. The models are tested against various flow cases, including flat plate boundary layers, free shear layers, adverse pressure gradient flows, backward-facing step flows, and NACA 4412 airfoil flows. The SST model shows superior performance in adverse pressure gradient flows, accurately predicting separation and viscous-inviscid interactions. The BSL model performs similarly to the original $ k-\omega $ model but avoids freestream sensitivity. The paper concludes that the new models are more robust and accurate, with the SST model being particularly effective for aerodynamic applications. They require more programming effort but offer improved stability and performance. The models are tested on various grids and show grid independence. The authors emphasize the importance of empirical validation and the need for rigorous testing of turbulence models.