本课题拟通过理论研究、数值计算和实验分析，进行泵系统特别是带长管道的泵系统气液两相瞬变流及其水锤的气阀防护研究。旨在研究长距离管道中泵突然失电导致的管道中压力下降液体产生汽化后形成气液两相流的运动机理，推导管道中考虑相间质量交换、空穴变化率及其带来的变波速的气液两相瞬变流控制方程；将Steger-Warming FVS(矢通量分裂法)和NND格式相结合，构成一种能自动准确地捕捉到两相瞬变流中的激波的差分方法；建立与实际吻合的气阀的质量流量方程,通过实验研究空气阀的过流特性，即空气质量流量和压力之间的关系；从而确定空气阀的安装位置和口径对于水锤防护的影响，提出和研究新型的动力式的水锤防护气阀。本项目研究为长管道泵系统气液两相瞬变流及水锤的气阀防护研究提供理论依据和基础，从而保障长管道泵系统设备的安全可靠运行，获得最大的经济效益与社会效益。

The studies on gas liquid two-phase transient flow in the long pipeline system with pump baseed on Steger-Warming FVS (flux vector spiltting) are carried on in this topic,by theroetical study, numerical simulation and experiment analysis. The pressure in the long pipeline that might resilt from power failure in the pumping system will fall down,thus causing to vaporization even column separation. The formation mechanism of two-phase transient flow will be discussed. The control equations of gas liquid two-phase transient flow including the influence of two-phase interface mass exchange,cavity ratio change,and changealbe wave volocity can be calculated. The Steger-Warming FVS method and NND format are hybrided to form finite differential format that is stable and capable of capturing the shock wave of two-phase transient flow auomatically and accurately.The mass flow characters of air-valve are studied by experiments to form the curves of air mass flow and pressure of air valve. The experiments show the influence of location and dimension of air valve on water hammer protection. A newly-type air valve is studied and suggested to overcome some shortcomings of the former air valve. The studies of this project are important reference of theory and foundation of gas liquid two-phase transient flow in the long pipeline system with pump. The water hammer protection is used to improve the safety and relaibility of the long pipeline system with pump and to get the greatest economic and social benefits.