Modification of K-ε turbulence models for coaxial sudden-expansion swirling flows

A successful prediction of turbulent swirling flow, which is important for simulation of gas turbine combustors and ramjet combustors, required a reliable turbulence model. The standard k-ε model which is commonly used for engineering practice is reported in less satisfactory agreement with the measured results for the flows incorporated with high streamline curvature effects. Several modified k-ε models have been studied and compared with the measurements in literature. It was found that the modified k-ε models can help improve the predictions of high-swirl-strength flows, but the improvements were not so significant. The Reynolds stress models seem to be another potential method to provide satisfactory predictions for high-swirl-strength flow fields.