Aerodynamic Noise Simulation And Experimental Measurement Of The Cross-Flow Fan

Due to structural relatively simple, relatively small and the wind is blowing straight and uniform, high dynamic pressure coefficient and low noise. Cross-flow fans are widely used in air conditioning,Laser equipment and ventilation technology, applications which require a low and wide flow rate.A cross-flow fan consists of a cylindrical rotor, forward curved blades, and a volute. Due to the flow non-axial symmetry the so called eccentric vortex is produced, the center of the vortex is inside the rotor near the vortex wall, this affects the flow structure in the blade channels, the air flows from the suction into the blades radially, Outflow from another direction by accessing the impeller and blade channel twice. Since the cross-flow fan's geometry and flow structures are complex, the aerodynamic noise forecast model is still a pending problem.In this paper, firstly, through experimental analysis the acoustic characteristics, that is noise frequency spectrum of the cross-flow fan, and so accumulating the flow field -sound field experimental data. Use the Fluent software to build the experimental cross-flow fan's model and numerical simulation, and get the flow and near-field sound certain details and also get the cross-flow fan's noise frequency spectrum and the direction of sound pressure level mappings at different speeds.Experimental study, on the one hand, by using of the Precision Integrating Sound Level Meter to measurement the far-field sound pressure, and draw the radial direction of sound pressure level, and also do a comparison with simulation. On the other hand, based on NI Data Acquisition System, by use of acoustic sensors to measurement the cross-flow fan's far-field sound pressure, at the same time by use of the various analytical tools in LabVIEW software for data processing, through the Fourier Transform and wavelet analysis and get the cross-flow fan's noise frequency spectrum.Through comparison the experimental and numerical simulation results at the same point in the same condition, the results show that numerical simulation is reliable in flow field, however, by comparison with experimental data, the simulation in calculating the sound field is still existing certain deviation. Because of the Aeroacoustics Experimental Bench is still under construction and the experimental conditions restriction, the experimental data collection and experimental work is only a preliminary attempt in this paper, the accuracy of date and experiment needs to be raised in order to offer a better reference and recommendations in future work.