The Theory Research Of Mechanical Design

Centrifugal fans are widely used in aeronautic, power and energy, chemical engineering, metallurgy and many other industries. When the fluid contains solid particles as the working media through the turbo machinery, the solid particles entrained fluid will flow through the solid wall of the wear and tear resulting effect will enable a serious perforated flow and deformation of parts, the deterioration of the flow characteristics of fans. Especially for sintering, dust emission, such as boiler fans, because of solid particles on the surface of leaves and often the impact of the case, so that leaves and wear the most serious cases, even lead to breakage and leaves, such as Major Incident coaster. According to relevant statistics are available, including solid-gas - solid two-phase flow fan output accounts for about 40%, research shows that gas - solid two-phase flow fan wear is of great significance.In this paper, the first CAD software Solidworks on 4-72 and improved centrifugal fans centrifugal blower fan for the whole three-dimensional flow field modeling. Each of the overall air flow field model consists of three parts: entrance, impeller and the volute part of the region. Among them, the two body parts model and spiral case entrance part of exactly the same, only different impeller model. And in a special mesh software Gambit fan of both the overall model of three-dimensional flow field of the flow field channel model mesh and boundary condition . In order to compare the two types of centrifugal fan impeller internal flow field of the difference between the two fan models overall selection in the same grid cell and the same mesh parameters and set up exactly the same boundary conditions. Finally the use of CFD software FLUENT, using the standard k ?εturbulence model, using the separation implicit solver, respectively, the two types of centrifugal blower fan inside the overall three-dimensional flow field numerical simulation, the latter in the calculation of the results of treatment in the same coordinates Department of static pressure and velocity vector of parameters, such as analysis and comparison, the results show that: the same parameters improved conditions and improved centrifugal fan centrifugal fan impeller before the internal flow field has greatly improved, improved ventilation centrifugal plane leaves on the sand before the relative improvement in flow rate more uniform distribution and the location of the speed of the larger value of the region and after the leaves are not the contact plate, the blade static pressure points more evenly, from roots to the top of gradually increasing contact with leaves and post-plate reduce the high-pressure area is very obvious that the pressure gradient improved significantly smaller. It is expected to improve the wear resistance after the centrifugal fan will have greatly improved.