The cooling technology for internal gas turbine blades is crucial to gas turbine performance and longevity. Heat transfer and flow behavior play a significant role in the effectiveness of turbine cooling. Internal cooling involves air circulation within the hollow passage of the cooling channel. Geometry, surface roughness, temperature, and pressure distribution influence the cooling performance. The turbulence simulation technique plays an important role in predicting the flow behavior. In gas turbine blade internal cooling, turbulence models help capture the intricate flow phenomena, such as vortices, mixing, and heat transfer enhancements, caused by turbulent eddies. Over the years, researchers have faced difficulties in choosing the right turbulence models, as the accuracy of the selected model is crucial for obtaining reliable predictions of the flow behavior and heat transfer. This study compared three different turbulence models, such as Large Eddy Simulation (LES), K–ε, and SST K–ω, with experimental data.