Flow Characteristics of a Model Can-Type Combustor

Abstract

Numerical simulations are performed on a can-type combustor in order to indentify various flow features. Elementary flow features like jet-in-crossflow, opposed jets, swirl and recirculation zones are present in a combined form. Momentum flux ratio between axial air flow and radial primary air jets from the circumference of the combustor is an important parameter. While increasing mass flow rate of the radial jet, the jet-in-cross flow structure changes to opposed jet. Swirl of axial jet is favourable for opposed jet configuration. A step provided at the close vicinity of the primary jet allows the primary jet expansion and its flow structure is affected at the entrance of the combustor to favour for jet-in-cross flow configuration. The opposed jet configuration provides large recirculation at the upstream due to merging of vortices arising from swirl of axial jet and upstream movement of primary air jet. This helps in holding the flame and also for effective combustion. However, there is a lower temperature region at the downstream core of the combustor due to penetration of primary air jets. On the other hand, jet-in-crossflow configuration has shown hotter zone at the downstream core of the combustor. Hence, effective utilization of flow structure can be considered in future design.