Design Of A Multi-blade Centrifugal Fan

With the rapid development of modern industry, fan products has been more widely used in various industries, including oxygen top blowing steelmaking metallurgical industry, aviation and defense industries of wind tunnel experiments, range hoods and other civilian. The fan of the home range hood is a multi-blade centrifugal fan. As the fan theory is still not perfect and the flow field inside the fan is very complex and not visible, which is difficult to accurately describe, many of the design parameters are still dependent on empirical data, getting performance of a fan is also dependent on an experimental test, spencially the fan design for a household hood which is used in more complex conditions. To develop a better performance of a multi-blade centrifugal fan is very meaningful, that is able to reduce development costs and reduce development time, and it also can improve market competitiveness, occupy more market share. The main contents of this article are:(1) The overall design of a multi-blade centrifugal fan. Clarify the basic theory of multi-blade centrifugal fan and its applications, discusses the basis why the range hood use with a multi-blade centrifugal fan, and establish a development process of a multi-blade centrifugal fan.(2) The preliminary design of the multi-blade centrifugal fan. With the Parameters of a multi-blade centrifugal fan system calculated, initially identify the geometry of the multi-blade centrifugal fan and motor power requirements, such as the impeller, volute, motor power, etc. but a lot of process parameters are based on experience or empirical formula corrected.(3) The CFD simulation of a multi-blade centrifugal fan, through numerical simulation of the multi-blade centrifugal fan, we not only can get air performance parameters under the given speed, PQ curve, η-Q curve and broadband noise source model a sound power level of noise of the rototype,but also can indicate the status of the prototype image of the flow field, including all regions, each plane, the pressure on the size of the wall, the velocity magnitude and direction of flow lines, noise, etc., with the above parameters we can be basic Learn the worst positions of prototype flow conditions, the noisiest areas of the region, the vortex regions, and provide references with further optimization.(4) The DOE optimization of the multi-blade centrifugal fan, as the DOE optimization of the multi-blade centrifugal fan conduct, with 16 kinds of random combinations of numerical simulation results instead of the experimental test results of two levels of seven factors, we can get the fan important of the factors and the regression equation on seven factors, any performance of 128(72) products can be seen. Of course, you can also get the best combination of the factors. It can largely save fan prototyping costs and the experimental test of time.(5) The experiment of the multi-blade centrifugal fan, through the experiment of the multi-blade centrifugal fan, the results showed that the optimum fan performance has obvious better advantages than the prototype, and the results of variation of the fan air performance parameters is consistent with the numerical simulation, so numerical simulation can be used in place of a portion of experiments is feasible.