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牛津大学发展了一种新型暂冲式叶栅风洞,它大为完善了对涡轮叶片上传热率分布的认识。该叶栅风洞详情见。主要设备如图1所示。它包括——压气管,其中有——自由活塞,靠高压空气以130大气压推动。试验气体在约0.75秒内被压缩,达到预期的总压力和相应的温度。有一快速反应的压力传感器测量总压力,其输出触发一个闸伐,使在0.03秒内打开,压缩并加热的试验气体即通过叶栅排入缓冲箱。如果使节流口的容积流量(ρ*a*A*)b等于从高压空气并流过它与压气管间的节流口的容积流量(ρ*a*A*)_r,则活塞前的总压力就保持为常数,直到活塞移到泵管末端。流动持续时间则与叶片喉口面积和总压力(及总温)有关。在牛津大学工程实验室(下简称OUEL)叶栅风洞中,对于典型的叶栅喉口面积,流动持
Oxford University developed a new type of transient cascade wind tunnel, which greatly improved on the turbine blade heat transfer rate of awareness. See details of this cascade wind tunnel. The main equipment shown in Figure 1. It consists of - a pressure tube with a free piston driven by high pressure air at 130 atm. The test gas is compressed in about 0.75 seconds to achieve the desired total pressure and the corresponding temperature. A rapid response pressure sensor measures the total pressure and its output triggers a brake that allows the test gas, compressed and heated, to be released in 0.03 seconds into the buffer tank through the cascade. If the orifice’s volume flow (p * a * A *) b is equal to the volumetric flow (p * a * A *) _ r from the high pressure air and through the orifice between it and the pressure tube, the total The pressure is kept constant until the piston moves to the end of the tubing. The duration of flow is related to the leaflet throat area and total pressure (and total temperature). In the University of Oxford Engineering Laboratory (OUEL) cascade wind tunnel, for the typical cascade throat area, flow holding