simulation study on the performance of the air ejector with nozzle topological structure
In this paper,the topological method was used to optimize the structure of the working nozzle so as to delimit the efficiency of the ejector.A new cone-like spoiler element ejector was proposed based on the optimization result and drag reduc-tion mechanism.The evolution law of the internal flow field of the new ejector was studied by numerical simulation method.The mechanism of the spoiler and the influence of the maximum thickness of the spoiler and the distance from the nozzle inlet on the performance of the ejector were analyzed.The results show that the spoiler element causes an oblique shock wave at the nozzle outlet.The oblique shock wave is reflected as expansion wave in the jet boundary layer,so that the jet diffuses rapidly during the movement and the entrainment ability of the primary fluid is enhanced.The entrainment ratio increases first then decreases with the increase of the maximum thickness of the spoiler and it increases with the increase of the distance from the nozzle inlet.The entrainment ratio of the new ejector can be increased by 45.6％～101.2％compared with the traditional ejector.The ejector has the best performance when the maximum thickness of the cone-like spoiler is 3.6 mm and the distance from the nozzle inlet is 22 mm.At this time,the entrainment ratio is 0.83.
Air ejectorTopology optimizationCone-like spoiler elementEntrainment ratioNumerical simulation
NETL
NSTL
万方数据
