CAJ | 학술논문

综合运用现代计算流体力学方法对某型号中压低温透平膨胀机增压端的三维定常黏性流场进行了数值模拟，详细研究了轮背间隙和密封腔内的刮削回流现象、动叶通道内的流场气动参数以及无叶扩压器内的流动特性对整机气动性能的影响。研究结果表明：气封齿和盖板缝隙内的局部射流是形成气封齿内旋涡旋向的主要因素；轴封槽内存在较大的旋涡且挂在齿尖上，这是由于齿尖区域的节流作用导致的；无叶扩压器和蜗壳通道内的流动具有很强的三维不均匀性，自蜗舌位置开始顺时针方向约45°范围内压力和温度都明显低于其他周向位置，影响了蜗壳的气动特性。数值计算结果为膨胀端的气动优化和改型设计提供了依据。
종합운용현대계산류체역학방법대모형호중압저온투평팽창궤증압단적삼유정상점성류장진행료수치모의，상세연구료륜배간극화밀봉강내적괄삭회류현상、동협통도내적류장기동삼수이급무협확압기내적류동특성대정궤기동성능적영향。연구결과표명：기봉치화개판봉극내적국부사류시형성기봉치내선와선향적주요인소；축봉조내존재교대적선와차괘재치첨상，저시유우치첨구역적절류작용도치적；무협확압기화와각통도내적류동구유흔강적삼유불균균성，자와설위치개시순시침방향약45°범위내압력화온도도명현저우기타주향위치，영향료와각적기동특성。수치계산결과위팽창단적기동우화화개형설계제공료의거。
In this paper , three‐dimensional steady flow in the medium‐pressure cryogenic turboexpander was simulated with the computational dynamics fluid method ,and the scraping backflow in the gas seal ,flow parameters in blade passage and vaneless diffuser were also studied in detail .The results show that the rotation direction of vortices motion is controlled by local jet flow between gas seal and cover plate .Because of the choking effect of tooth point ,there is a big vortex in shaft seal .The flow field of vaneless diffuser is non‐uniformed ,so that pressure and temperature in the range from volute tongue to clockwise 45 degree were high above than other place ,which affected its gasdynamic performance .The computational results provide the basis for aerodynamic optimization and modified design of turboexpander .