Computation of Flow through an Annular Diffuser and Volute Exhaust

  • M. Arun Indian Institute of Technology, Madras
  • E.G. Tulapurkara Indian Institute of Technology, Madras
  • T. Sundararajan Indian Institute of Technology, Madras
Keywords: Conical diffuser, annular diffuser, swirl parameter, turbulence models, turbulent flow, computer model, computation, diffusers


Turbulent flow in a diffuser with swirl occurs in many commonly used fluid mechanical
devices,eg, diffusers located downstream of a gas turbine, and in certain types of combustion
chambers. Diffusers are widely used for converting kinetic energy to pressure, and a reliable
prediction method of such flows with the required flow conditions would lead to the design of
fluid machinery with improved efficiency. As a first step, turbulent swirling flow through a 12o
included angle conical diffuser for a swirl parameter, m = 0.18 was numerically investigated using
various turbulence models like standard k- , RNG-based k- , shear-stress transport (SST) kand
Reynolds stress model (RSM). Though the comparison between the experimental and the
predicted mean velocity profile by RSM is superior to that by RNG kand
SST models, the latter
two models give closer comparison with the experimental pressure distribution. Subsequently,
computation of flow inside a complex duct involving axisymmetric annular diffuser, transition
from rectangular to circular cross section, and exit pipe have been carried out using RNG kand
SST k models.
The comparison of computed and experimental results indicates that the
SST k model
gives predictions with reasonable accuracy.
How to Cite
Arun, M., Tulapurkara, E., & Sundararajan, T. (2006). Computation of Flow through an Annular Diffuser and Volute Exhaust. Defence Science Journal, 56(2), 147-158.
Applied Physics & Fluid Dynamics