吸入室角度对环形射流泵空化性能的影响

Influence of inclined angle on cavitation performance of annular jet pump

利用数值模拟的方法研究环形射流泵(AJP)内的空化发展规律,比较分析不同吸入室角度对环形射流泵空化性能的影响,得到如下结论.1)Realizable k-ε湍流模型结合mixture多相流模型及Schnerr-Sauer空化模型可以较好地模拟环形射流泵内的空化现象.2)随着环形射流泵出口压力的降低,喉管入口壁面处的空化区域会向喉管内延伸,引发的低压区会不断地向轴心线扩展.当低压区扩展到轴心线时,喉管内空化区剧烈发展,环形射流泵进入极限工况.3)当空化数大于极限空化数时,环形射流泵效率不受空化的影响;当空化数降低至极限空化数时,环形射流泵的效率陡降,空化数保持恒定不再降低,对应的值是极限空化数.4)吸入室角度越小,各个流量比对应的极限空化数越小,泵的空化性能越好.较小的吸入室角度使得环形射流泵更易诱发回流中心及剪切层空化云的产生.

The numerical method was conducted to analyze the development of the cavitation in annular jet pump（AJP）,and the impacts of different inclined angle on the cavitation performance of AJP were comparatively analyzed.The following results were obtained.1）Combined with mixture model and SchnerrSauer model,realizable k-ε model can reasonably simulate the cavitation phenomenon in AJP.2）With the decreasing outlet pressure of the AJP,the cavitation area at the inner wall of the throat inlet will stretch alone the throat and the induced low pressure will extend to the axis.When the low pressure attaches to the axis,the cavitation in the throat boosts and the pump turns out to be under operating limits.3）When cavitation number is larger than limited cavitation number,the efficiency of AJP varies little regardless of the developing cavitation.When cavitation number drops to the limited cavitation number,the performance of AJP suffers a great decrease,while the cavitation number will stay constant and the corresponding value is the limited cavitation number.4）The smaller the inclined angle is,the smaller the corresponding limited cavitation number is and the better cavitation performance of AJP is.The cavitation cloud is easier to be induced at the center of the recirculation and the shearing layer with a smaller inclined angle.