Influence of niche size on jet fan effect in underground railway tunnel

At present, jet fan uses niche type in most underground railway tunnels. Simulates and analyses the jet performance under the different conditions of as many as forty-five sizes of niches and non-niche using CFD, and ultimately determines the effect of the different size of niches on rise pressure and induction length of the jet fan. Proposes the recommendated niche size for the design of the jet fan.