Flow Field Analysis Inside an Annular Combustor Using CFD

Abstract

Present work is concerned with the flow field analysis inside an annular combustion chamber. Geometry is modeled with all the complexities taken into account which includes swirler, atomizer, thickness of casing and liners to include real hole effects in primary and dilution holes, dome and flare part of the combustor and liner holes. There are around 790 holes in dome and 678 holes in flare part of the combustor and each of 1mm diameter. There are around 250 cooling ring holes to protect the liners. GAMBIT preprocessor is used for modeling the complex geometry. Only 20° sector is generated for analysis because of the rotational symmetry of the geometry. A parametric study has been carried out by varying the number of holes in the dome and flare part of the combustor. Diameter of the holes is varied from 1mm to 3 mm in steps of 0.2 mm. Total pressure loss is calculated across the combustor, dome and flare region for different hole diameters. A study on the effect of diameter of primary and dilution holes across the combustor is also carried out. It is found that there is no appreciable change in total pressure loss for different hole diameters of dome and flare part whereas the primary and dilution hole diameter plays an important role in determining the total pressure loss. In order to validate the code, experimental results are taken from the literature (Koutmos and McGuirk 1989) where a water model Can-Type Combustor is used for flow analysis with different mass flow rate through the swirler. The agreement between the two is reasonably satisfactory.