摘要
喷射器内部的流动非常复杂,其流动现象很难通过实验观察,并且喷射器的加工精度要求非常高,这些对于喷射器的设计理论发展是个很大的障碍。本文选用k-ε模型,运用CFD技术对喷射器进行模拟,主要研究不同的喷嘴位置对喷射器的影响。选择喷嘴出口距离混合室入口距离分别为0mm、3mm、5mm、7mm、9mm和11mm时,发现在7mm的时候能够达到一个最大的喷射系数,当距离大于7mm时,会造成工作蒸汽的回流,而使得喷射系数降低。当小于7mm时,虽然喷嘴出口的压力变化不会太大,但是工作蒸汽进入混合室前没有足够的距离来引射蒸汽,喷射系数还是比较低。
It is quite difficult to learn the inside flow of ejector because of its comply＇flow, furthermore, high manufacraring precision of ejector is also barricade for the ejector theory improvement. CFD mdthod is used in this paper with k -ε model, to solve the influence of nozzle position on ejector. The distance of nozzle out,to the mixing chamber inlet is chosen as 0mm, 3mm, 5mm, 7mm, 9mm and 11mm, a maximum ejector entrairnment ration is found when the distance is 7mm.When the distance is more then 7mm, circumfluence will appear, so the entrainment ratio will decrease rapidly.When the distance is less then 7mm, although the pressure changing out of nozzle is small, but the distance is too short for the working fluid to entrain secondary flow, so the entrainment ration is still low.
出处
《制冷》
2007年第4期16-19,共4页
Refrigeration
基金
上海市重点学科建设项目(T0503)
