知识与财富的链接
利用示踪气体浓度值分析圆形喷口非等温冷射流对周边环境空气的卷吸运动。利用恒温恒湿实验室进行喷口射流模型实验。对比了传统方法和示踪气体法卷吸量测量结果,并对喷口射流沿程卷吸量与卷吸系数的变化规律进行分析。实验数据表明:利用示踪气体浓度值沿程变化测量射流卷吸量的方法是可行的。在惯性力起主导作用的射流运动中,雷诺数Re是影响射流卷吸效应强弱的主要准则,随着出口Re数增大,卷吸量逐渐增加;当出口雷诺数Re>15000时,流量增大系数几乎不变。
The paper used tracer gas concentration to analyze the entrainment movement of ambient air by the non-isothermal cold jet coming from the circular nozzle. The model experiment of nozzle jet has been conducted in the thermostatic and humidistatic laboratory.It compared the result of the entrainment volumes derived from the traditional method and the tracer gas method, and analyzed the patterns of entrainment volume and the entrainment coefficient along the jet curve. The results show that the method of measuring the jet entrainment according to on-way changes of tracer gas concentration is feasible. The Reynolds number is the dominant physical factors in the movement of jet where the inertial force plays a dominant role. With the increase of Re number, the volume of entrainment increases gradually, when Re＞15000, the flow increase coefficient almost keep the same.
