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Overreliance on petroleum products and environmental pollution from combustion emissions produced by automobiles has led to extensive research on hybrid electric vehicles, electric vehicles and their components. A key component in these vehicles is the electric motor, used for traction as well as powering other appliances like the compressor. Overheating in electrical motors results in detrimental effects such as degradation of the insulation materials, magnet demagnetization, increase in Joule losses and decreased motor efficiency and lifetime. Hence, it is important to find ways of optimizing performance and reliability of electric motors through effective cooling and consequently reduce operating and maintenance costs. This study describes 3D CFD simulations performed on a totally enclosed air over fan cooled brushless D.C. motor to identify the temperatures of the critical components of the motor.

During braking, the kinetic energy and potential energies of a moving vehicle are converted into the thermal energy through frictional heat between the brake disc and the pads. Most of thermal energy dissipated through the brake disc. The object of the present study is simulation of heating and cooling processes of brake disc to investigate temperature field and temperature variation during driving along a downhill road. The velocity of automobile is limited by repeated brake when the speed exceeds to the maximum limited. The pad-disc brake assembly is built by 3D model and applied appropriate boundary condition. In the simulation process, the mechanical loads are applied to the thermo-mechanical coupling model in order to simulate the process of heat produced by friction. The Analysis results are compared to the measured data obtained from the downhill road brake experiment. The temperature field distribution in the disc under repeated braking presents a non-uniformity characteristic.

The ventilated disc brake is divided into a disc with several vents, and the pads with the three dimensional geometry. The frictional heat can cause high temperature during the braking process. The thermal distortion of the brake disc can affect the performance of brake system. The object of present work is determination of temperature distribution and thermal distortion in the disc by two dimensional thermal analysis. During brake, heat flux and convective transfer coefficient are considered as a function of time. The brake disc temperature is found to be satisfactory compared with that of the conventional three dimensional analysis. Thermoelastic deformation of the disc is found from the same axisymmetric finite element model with equivalent mechanical properties. The analysis results are also compared to the measured data in the brake disc thermal experiment.