Variant Design Andaero-acoustic Prediction Of Axial Flow Fan With Low Pressure And Swept-Curved Blades

Along with the fan industry relevant national standard files came on stage, theefficiency and noise value of fans were limited. So retrofit the current fans which havelow efficiency and high noise is urgent. In recent years, swept-curved blades were appliedto the field of low pressure axial flow fan and achieved well energy saving and noisereduction effect. This paper aimed at the energy saving and noise reduction of the generalT35axial fan with low pressure in fan industry. Applying the swept-curved blades to theT35fans by using numerical simulation combined with experimental study, and predictthe aero-acoustic of the fan, which provided basis and references for the research ofenergy saving and noise reduction of axial fan with low pressure. This paper mainly donethe following work:Firstly, carried out a series of performance test for the existed swept-curved axialflow fan by changing the blade installation angle, blade tip clearance and blowing type.Studied the influence of the fans’ performance with different installation structure, so as toprovided basis for further optimization and matching application of the swept-curved axialflow fan. Done the modeling work of two sets T35fans with low efficiency&highaero-acoustic which were the same type but different size. Forecasted the performance ofthe original T35fan and the existed swept-curved fan by numerical simulation, thencompared to the experimental result to verify the reliability of the numerical simulationmethod.Secondly, combined with the given structure and performance parameters, putforward the variant design scheme of swept-curved blade, predict the total pressureperformance and efficiency of the scheme, analyzed the internal flow field of the twoschemes. Combined with energy efficiency standards and user’s requirements, selected thebest modification design scheme. Considered the actual production and domestic demand,selected one kind of plan for processing, and carried out the performance test for the new fan, the test result showed that the new type fan’s performance improved significantlycompared with the original prototype.At last, for the problem of the aero-acoustic of the fan, according to the result ofsteady calculation, analyzed the turbulence noise of the fan by the broadband noisemodule in FLUENT. Compared the stand or fall of two schemes in further. Based on thesteady calculation, used the large eddy simulation (LES) to conduct to the unsteadycalculations, to get the information of flow field such as the pressure pulsation on theblade surface and so on. Combined the LMS Virtual. Lab Acoustics to conduct theaerodynamic noise prediction on the blade surface and far-field of the fan. Compared thepredict value and test value of the far-field sound pressure level of the measuring point,which provided experience and method for the research of aero-acoustic prediction offans.