船用燃气轮机排气红外抑制装置的流动分析

本文在分析船用燃气轮机排气系统红外抑制装置结构特点的基础上，从数值计算和实验测量两方面分析了该装置结构参数对气流流场的影响，以及温度场的分布规律，得到了若干结论，为工程设计和分析排气系统红外抑制装置提供了理论依据，具有一定的实用价值。     

德国磁悬浮列车的悬浮与驱动系统

论述了德国磁悬浮列车悬浮与驱动系统的工作原理、特性参数、控制和供电技术,说明了该系统与直线同步电机的关系,并列举了磁悬浮列车的优缺点。     

The Tip Leakage Flow Structure of an Axial Fan with Tip Clearance

Experiment and numerical simulation technique are used to investigate the tip leakage flow in an axial fan with tip clearance at the design condition. The flow field in the tip region of fan is measured using a PDA (Particle Dynamics Analysis) system. The flow is surveyed across the whole passage at fifteen axial locations (from the 100% axial chord in front of the leading edge to the 100% axial chord behind the trailing edge), mainly focusing on the outer 90% blade span. Both experiment measurement and numerical simulation indicates the leakage flow orig-inated from the tip clearance along the chord rolls-up into three-dimensional spiral structure to form leakage flow vortex. The interaction of leakage flow and main flow will produce the low velocity zone, and block the flow. The leakage flow almost occupies the most part of flow passage behind the trailing edge.