Flow and Pressure Characteristics Study of a Hybrid Diffuser with Fence

摘要

In this paper, the performance simulation of a hybrid diffuser with fence has been carried out. The two-dimensional steady differential equations for conservation of mass and momentum have been solved for the Reynolds number ranging from 20 to 500. During the simulation, the distance of fence from throat with the range of 0.2 to 2, aspect ratio of 2, fence subtended angle of 100 and half divergence angle of 3.50 have been considered. At the inlet, fully developed velocity profile has been used. The effect of each variable on average static pressure, stagnation pressure, maximum static pressure rise, stagnation pressure drop and streamline contours has been studied in detail, and compared with hybrid diffuser without fence. From the study, it has been revealed that a diffuser having configuration of sudden expansion with diverging section is beneficial in terms of pressure recovery. When a fence is incorporated at some distance downstream the throat, the maximum static pressure rise has been found higher as compared to without fence configuration of a hybrid diffuser for the entire range of Reynolds number considered. It has been observed that presence of a fence marginally reduces the stagnation pressure drop but the fence location does not have any significant effect on the variation of stagnation pressure. The best performance of the diffuser has been obtained when the distance of the fence from throat is held at 0.5.