A parametric study on the improvement of pressure recovery coefficient of a conical diffuser using Computational Fluid Dynamics

The easiest and most practical way to make any system more environmentally friendly is to increase its energy efficiency. In a commercial gas turbine, this is done by attaching a diffuser at the turbine exit. The purpose of this study is to determine the combination of flow parameters and the diffuser design that would lead to the improvement of the pressure recovery coefficient of such a conical diffuser, and hence the overall efficiency of the turbo machine, like an industrial gas turbine, to which the diffuser is attached. The flow in a diffuser was simulated using Computational Fluid Dynamics (CFD) software (Star CCM+). The performance of the diffuser under different conditions was studied. The parameters under consideration were the half cone angle of the diffuser and the swirl number of flow. The study concluded that the highest pressure recovery coefficient, which corresponds to maximum efficiency, was obtained in the diffuser with a half cone angle of two degrees and swirl number 0.5.