多截面细径管结构参数对放气系统压降特性的影响

采用数值模拟方法研究了多截面细径管结构参数对放气系统压降特性的影响,得到了导管几何尺寸、导管内壁粗糙度和出口压力等参数对压降特性影响的变化规律。研究结果表明:缩短容器导管长度或扩大其内径对壅塞状态下的压降影响较小,但可以显著提高层流状态下气体的流动速度,从而减少放气时间;内壁粗糙度对壅塞状态下的压降特性影响较大,随着粗糙度的增大,压力下降速度有所降低,而对层流状态下的压降特性影响较小,在容器压力降至极低的情况下,粗糙度的影响可以忽略不计;出口压力对整个流动过程的放气速度影响较小,出口压力的进一步提高不会明显增加放气速度。该研究可为多截面细径管放气系统的优化设计提供依据。

Influence of structural parameters of a multi-sectional small diameter tube in a deflation system on the pressure drop characteristics

The influence of the structural parameters of a multi-sectional long thin tube on the pressure drop characteristics of a deflation system is studied by numerical simulations, and the relationship between the structural parameters and the pressure drop characteristics is obtained. The results indicate that the flow velocity of the gas under laminar flow conditions is greatly increased by decreasing the length or increasing the inner diameter of the tube, but the pressure drop under chocked flow conditions is hardly affected by the change of structural parameters. The roughness of the inner tube has a great influence on the pressure drop under chocked flow conditions, but has a smaller influence on the pressure drop under laminar flow conditions. It is also found that the outlet pressure has nearly no influence on the deflation velocity during the whole flowing process, which means that the deflation velocity will not be increased by increasing the outlet pressure. These results provide some guidance for optimizing the design of small- diameter tubes in the deflation system.