A Variant Design And Aero-acoustic Analysis Of Swept Axial Flow Fan Used For Cooling

Axial flow fan plays a central role in various industries. of The axial flow fans withhigh efficiency and low noise have some mature models, but each type of models has itssuitable application occasions, when be used for other occasion will appear themismatching problem of specifications or performance. Based on the superiority of theswept axial flow fan, we applied it in the occasion transformer cooling, and put forwardthe variant design method to solve the mismatching problem.Get the structure size and test data of the axial flow fan, determine the calculatingarea of rotation area, import and export wind ducts, establish and meshing the calculationmodel, then choose the appropriate calculating method for the steady numerical simulationand external performance prediction. Compare the Ptf-Q performance curve got bycalculation and testing to verify the correctness of the numerical simulation method.Obtain five plans A/B/C/D/E of swept axial flow fan using variant design method tomeet the given flow and the pressure requirements, and predict Ptf-Q and η-Q performancecurves adopting the same calculation method, then screen out B/E fans that meet thepressure and flow requirement with high efficiency. Analyzed the distributioncharacteristics of pressure and speed streamline on the axial and radial flow surface of thefive fans, and further verified the superiority of screened fans. The performance test of fanE was conducted after the impeller process completed, and the simulation andexperimental data results were fit well.Taken the steady flow field as the basis, the large eddy simulation (LES) and theFW-H method based on the Lighthill sound analogy were adopted to simulate the unsteadyflow and predict aerodynamic noise of the B/E fans and the numerical results werecompared with the experimental data. We also analyzed the spectrum distributioncharacteristics of the eddy noise from the B/E fans when the impeller surface was regardedas the noise source, researched the vortex distribution characteristics in the fans’ internal three-dimensional unsteady flow field, and discussed the distribution mechanism of thesound pressure level in the impeller’s rotational region. Furthermore, we explored the timedomain and frequency domain properties of aero-acoustic in different position of fan E’internal rotating region with different speeds.Finally, we proposed the further research direction of swept axial flow fan’aero-acoustic combined with the summary and deficiency of the work in this paper.