Research On Two-level Motor’s Speed Matching For Counter-rotating Fan Performance

With the emergence of the long distance air supply, implementation forlong-term stable and high precision operation of counter-rotating fan has been adifficult problem. In this dissertation, based on the theory of counter-rotating fan,with the help of aid of computational fluid dynamics technology, used thenumerical simulation method, studied the complex flow of fluid inside thecounter-rotating fan, analyzed the aerodynamic performance of counter-rotating fan under different working conditions, to lay the foundation ofmatching of two levels of motor and the efficient and stable operation of counter-rotating fan.First of all, introduced the structure of counter-rotating fan, and theconversion of cyclone machine parameters, then take a series of FBD5.0counter-rotating fan for example, starting from the actual, take the way of Subsectionmodeling, two levels of impeller takes the method of3D scanning method, therest were completed in Solidworks, and then got them together to establish thedomain of counter-rotating fan3D flow field model.The second, following the basic theory of counter-rotating fan and the threelaws of fluid, select the appropriate import and export conditions, to do thenumerical simulation of the internal flow field of fan in Fluent software. Tocompare the P-Q curve of numerical simulation with the P–Q curve ofperformance test, the accuracy of the numerical simulation method is verified.The last, changed the axial spacing of counter-rotating fan, drawn the staticpressure change and efficiency characteristics under six axial spacing, analyzedthe most suitable axial spacing for counter-rotating fan. Changed the two levelsof motor speed respectively, do the numerical simulation analysis for the counter-rotating fan with selected four kinds of speed matching in this dissertation,chosen seven different working conditions to the research on the changes of the performance parameters of the counter-rotating fan.