Numerical calculations of turbulent flows in a dump diffuser

Abstract

A finite-volume numerical calculation method for the solution of two-dimensional incompressible steady Navier-Stokes equation in general curvilinear coordinate system is presented.The main solution algorithm of the method is an extension of SIMPLE algorithm t o present general curvilinear coordinate formulation, maintaining the Cartesian velocities as dependent variable. The standard k-€ turbulence model i s used for closure of the Reynolds equation. Tliis method is applied to calculation of turhulent flows in a two-dimensional planar dump diffuser with uniform and distorted inlet velocity Profile, and the results are compared with the data obtained from experiments carried out in this study. The general flow pattern and velocity distribut.ion are success full^ predicted and the results show good agreement with experimental data, especiall~ using the QUICKER scheme for finite-difference approximation. Pressure loss can also be predicted using fine grid. but improvement must be achieved in the computational method to be able to predict pressure loss with moderate grid.The treatment of the pressure correction equation employed in this work enforces stahility and robustness of the computational method.

CFD contribution to development of HYPR engine

“…By assuming an incompressible flow, the buoyancy effect was ignored in the calculation. A detailed description of the code is given by Ando et al (1986).…”

Influence of the Dump Gap on the Performance of Dump Diffusers

“…The performance of dump diffusers depends on a variety of parameters such as dump gap, dome depth, area ratios of the annuli, inclination of the combustor walls, flow split between the annuli [2]. In the past a lot of experimental and numerical studies [3][4][5][6][7][8][9][10][11][12] have been reported on the design and optimization of the dump diffuser. Owing to the complexity of flow field inside the dump diffuser, the design optimization of the dump diffuser remains an elusive task.…”

A Computational Procedure for Diffuser-Combustor Flow Interaction Analysis

“…Most of the applications (e.g., McGuirk and Whitelaw, 1984;Shyy, 1985;Ando et al, 1986;Karki and Patankar, 1986) of computational methods to dump diffusers have been restricted to simplified two-dimensional or axisymmetric configurations. These studies have primarily been directed towards the adequacy and applicability of the numerical procedures based on computational fluid dynamics for predicting the diffuser flows.…”