The Motor Of Middle Type Chassis Dynamometer Ventilation Cooling Optimization Research

In recent years, car ownership in China is gradually increasing, the air pollution is increasingly serious. Therefore, the automobile exhaust emission limit is more and more strict.The middle type chassis dynamometer use of the double shaft extension motor as dynamometer loading device, because both sides of the motor are output shaft, and are provided with a drum, not like ordinary motor as one end of the motor shaft is mounted cooling fan; the shell surface of the motor is smooth, its heat radiating area of the surface is reduced; the motor is installed in the underground excavation and needs long time of continuous instability operation in the durability emission test, all above put forward higher requirements on the ventilation cooling of biaxial stretched motor.In this paper, it is ultimately determined that use the flow field and temperature field coupling numerical analysis method through the consult massive literature on the research methods used for ventilation and heat dissipation of all kinds of project motor.A two-dimensional physical model of the double shaft extension motor stator and rotor is established through reasonably simplify of the practical model. The temperature and velocity contours of the motor is obtained through the conjugate heat transfer analysis of the flow field and temperature field coupling based on the commercial CFD software FLUENT after meshing. The experiment data are used to verify the model. Then, the relationship between the different entrance velocity effect on the flow field and temperature field of the motor is explored, and the motor’s ventilation system improvement scheme is put forward. The calculation results can provide reference for the optimized design of motor ventilation cooling system. The simulation of natural ventilation and 6 different mechanical ventilation scheme in the pit are carried on when it is installed in the foundation pit through the establishment of two-dimensional numerical model. This paper do the research about how the location of air vent affect the pit’s ventilation and heat dissipation when the motor is installed in the pit, the results can provide a reference basis for the design of foundation pit size and ventilation technical scheme.