| The contra-rotating fan is a special program on axial flow fans, twoimpellers driven by the motor directly connect, primary and secondary impellerseach other as rotor blades. It is compared with the ordinary axial flow fan thathas compact structure, high efficiency, and good anti-wind characteristics. It hasbeen widely used in tunnels, mines, subways, railway in recent years. Duringcontra-rotating operation, the blades as direct medium are subjected toaerodynamic, centrifugal force, driving force, the torque ripple caused by bladeaerodynamic directly affects the electromagnetic torque of drive motor. It isimportant that we should make more detailed analysis of the aerodynamic effectson blade structure and motor.Firstly, in this dissertation, the model for FBD5.0/2×7.5mine local contra-rotating fan is used as a research object, the model is drew by solidworkssoftware and gambit software on the basis of the specific analysis of the fanstructure.Secondly, describing the structure and operation principle of the contra-rotating fan. Based on the specific analysis experimental date, fluent softwaresimulate interior flow field about contra-rotating, analyze the flow phenomenaand two impeller pressure distribution. Fluid-structure coupling simulation wascarried out using Ansys workbench software. Form the simulation, we can studydetailedly two impellers’ deformation, stress and strain while contra-rotatingworking, compare the influence of the strength of two impellers in air pressureunder different speed match.Finally, this paper analyzes the air pressure pulsation around impellers fluiddomain based on2900/2900speed matching, the result is proved that air pulsecycle will have a component that larger amplitude and frequency is proportionalto the number of rotating blades. The use of parametric analysis method combined with the torque curve of contra-rotating fan to study the load torqueripple effects on motor electromagnetic torque and motor rotating speed. |
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