VISUALIZATION OF RECIRCULATION IN A LOW ASPECT RATIO DUMP COMBUSTOR

摘要

This paper describes an experimental study of the recirculating flow of air inside a dump combustor having a low length/diameter ratio and a tapered exit section. The length of the combustor studied was smaller than the reattachment length for the separated flow after the dump. The recirculation was driven by the fluid dynamics of the one-dimensional flow from a smaller area to a larger area. It was observed that the jet penetration increases with the increase in the flow Reynolds number. However, a distinct thickening of the recirculating flow was observed inside the combustor, which can be attributed to the flow reversal from the exit section, causing flow adjustment to fill the whole combustor with a recirculating flow. The findings of this study can have applications in the design of better combustors with proper alignment of the fuel injectors with respect to the flow for better evaporation and mixing of the fuel.