Dynamic analysis of flow field at the end of combustor simulator

Abstract

This study was carried out in order to extend database knowledge about the flow field characteristics and define the various flow field contours inside a combustor simulator. The modern gas turbine industries try to get higher engine efficiencies. Brayton cycle is a key to achieve this purpose. According to this cycle industries should increase the turbine inlet temperature to get more engine efficiency and power. However the turbine inlet temperature increasing creates an extremely harsh environment for the downstream critical components such as turbine vanes. In this research a three-dimensional representation of a true Pratt and Whitney aero-engine which studied before in Virginia University was simulated and analyzed to collect essential data. This combustor simulator combined the interaction of two rows of dilution jets, which were staggered in the stream wise direction and aligned in the span wise direction, with that of filmcooling along the combustor liner walls. The overall findings of the study indicate that three-component velocity measurements showed the dilution jet-mainstream interaction produced shear forces and as a result a counter-rotating vortex pair was created. The highest turbulent kinetic energy was found at the top of recirculating region due to the interaction of the second row of dilution jets and mainstream flow. Furthermore, the centers of the counter-rotating vortex pair were spread relatively far apart due to the opposing dilution jets. Along the dilution jet centerline, negative stream wise velocities were measured indicating the recirculation region just downstream of the jet. Into the combustor exit, the acceleration of the flow increased and thereby the uniformity of the velocity profile enhancement was found as well.