An Isothermal Investigation on the Effect of Swirl Intensity on Combustor Flow Regime.

Swirling flow is popularly used for flame stabilization in gas turbine combustion chamber. Swirling flow has three velocity components, namely, axial, radial and tangential. Relative strength of axial and radial momentum is described by nondimensional swirl number (S). Reduction in emission level is achieved by setting the correct value of swirl number. The present work reports a numerical study of steady flow through CAN type combustor utilizing swirler vanes. Three-dimensional flow through the combustor geometry with swirler is numerically simulated using FLUENT. Influence of swirler vane angles on flow and mixing characteristics of the combustor is analyzed. The vane angles considered for this analysis are varied between 15° and 60° in steps of 15°. Effect of turbulence is incorporated through k-ϵ model. The larger swirl intensity demands higher pressure for flow. Swirler with 45° vanes is found to have good mixing characteristics with optimum pressure penalties. [ABSTRACT FROM AUTHOR]