LAUSR

Abstract To study the operating performance of fans at high altitudes, a pressure-variable ventilation device able to vary the gas phase environment of fans and pipeline was designed. The fan performances at altitudes of 0 m, 900 m, 1900 m, 3000 m, and 4300 m were tested, and computational fluid dynamics (CFD) methods were used to simulate fan performance at high altitudes. The results indicated that under the same number of revolutions, as the altitude increases, the fan's output volume flow slightly decreases, the static pressure difference between the pressure surface and the suction surface of the blade decreases, the load of the blade decreases, the fan's output static pressure and shaft power linearly decrease, and the fan's static pressure efficiency nonlinearly decreases. In a high-altitude environment, the noise pressure pulsation interval and amplitude of fan noise are reduced, discrete noise and broadband noise are weakened at the same time, and the A sound level of each frequency band is reduced on a yearly basis.