Heat Transfer Modeling And Analysis of Annular Diffuser With and Without Double Tapered Struts

Abstract

Exhaust diffusers are critical components of gas turbines in both propulsion and power system applications. The factors influencing their performance are predominantly the area ratio, divergence angle and the length of the flow path over which diffusion occurs. Pressure recovery and pressure loss coefficients, relationships between static and total pressure and performance maps are generally used to determine diffuser’s performance. The main aim of the present work is to make a detailed analysis on various flow characteristics of the annular diffuser and determine the effect of struts on both the flow parameters and the overall performance of the exhaust diffuser. The cases under consideration are the annular diffuser with two different strut configuration namely the baseline and the tapered struts, and their comparison with the same diffuser model without any strut in the flow path. The diffuser is modeled and meshed using the pre-processor tool CATIA. In the present investigation, numerical simulation is carried out using STAR−CCM+, computational fluid dynamics software, which is based on the finite volume method and solves the three-dimensional Reynolds averaged Navier-Stokes equations, to predict the flow characteristics inside the diffuser and analyses the effect of struts. The details of the numerical simulation, solution procedure, turbulence model, boundary conditions, results obtained and the conclusions arrived at the results were discussed in detail.