Effects of lateral cooling hole configuration on a swirl-stabilized combustor

Abstract

It is necessary to cool the combustor liner due to its harsh operating conditions. In the current study, wall temperatures of a swirling combustor with and without cooling holes are compared using a three-dimensional numerical simulation with conjugate heat transfer method. It is shown that the wall temperature can be reduced by 344–501 K by using cooling holes. Two lateral coolant injection designs are then proposed since the laterally injected coolant may interact with the swirling flow. Normal axial injection is also investigated to compare NOx emissions, cooling effectiveness and total pressure loss for various scenarios with different injection angles. The results show that when the incidence angle is 15°, NOx emissions remain low for all incidence configurations. When the lateral incidence is implemented, especially at small incidence angles such as 15° and 30°, the cooling effectiveness is maintained above 0.9. However, when the coolant incidence direction is opposite to the swirling flow and the incidence angle is 15° results in a high total pressure loss. At an incidence angle of 60°, the total pressure loss is about the same for all cases, at 3.2%.