顶隙 meaning in English

bottom clearance
cupola space

The complex vortex system structure and shock wave system structure inside this rotor is obtained . wall flow patterns on the blade surface and hub surface are found out . the complex vortex system structure , such as horseshoe vortex , passage vortex , corner vortex and trailing vortex , and the interaction with shock wave system are researched . especially , the character of the tip clearance flow inside the rotor passage is revealed , and the interaction between shock wave and tip clearance flow near blade tip and the evolution of tip clearance flow are considered
给出了叶片表面及轮毂面上的壁面流型，分析并揭示了转子叶道内的马蹄涡、通道涡、角涡、尾涡等复杂涡系及其与激波的相互干涉；特别是，分析并揭示了转子叶道内顶隙射流的特点，得到了顶隙附近激波与泄漏流动的干涉形态及泄漏流动的发展，并着重给出了其与激波的干涉形态。