In this article, six kinds of reverse Brayton cycles of helium are studied analytically and the flow field of the header of their heat exchangers is simulated numerically. 本文正是基於上述考慮，選取了六種氦氣逆布雷頓製冷循環模式，並對其進行了熱力學分析，詳細地討論並對比了各個循環模式的用能情況，同時還對迴路中採用的換熱器封頭內部流場進行了數值模擬。
The flow field around the secondary filter was vividly characterized with a porous medium model, so that the flow pattern around this kind of filter was readily obtained. 多孔介質模型形象地描繪出了二次濾網的內部流場，獲得了該型號濾網的內部流動規律。
