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Aiming at improving the cooling of motor annular water jacket, the effects of different water jacket designs and pump rotation speed and epoxy resin filling on the flow field characteristics and motor temperature distribution were studied. Results show that uneven flow distribution leads to high temperature of motor coil and large temperature gradient. The optimized water jacket has better flow, uniform flow distribution of long and short paths, higher utilization rate of coolant, and the coil temperature is 2 °C lower than that of original model. On the basis of optimized water jacket, when epoxy resin filling methodology and pump rotation speed increased to 5000 r/min are applied, the coil temperature can be reduced by 16 °C compared with the original model. From the cooling performance optimization results in current case, the improvement order from the smallest to the biggest is the optimization of motor water jacket flow field, optimization of motor water jacket system flow rate, and the epoxy resin filling. To meet the cooling demands of motor, the comprehensive effects from the aspects of reducing coolant system resistance, increasing pump speed, epoxy resin filling and other effective technologies are ought to be considered for all case studies. [ABSTRACT FROM AUTHOR]

The comprehensive performance evaluation procedure and overall performance evaluation indices for the four cylinder engine cooling systems are proposed in this work and the four cylinder engine cooling system with two different flow patterns are investigated. Coolant velocity distributions of nose bridge area sections of cylinder head water jacket and plane section of cylinder block water jacket in series flow pattern cooling system meet the coolant flow velocity requirements of 1.5 m/s in high-temperature area. Coolant velocity distributions of water jacket in parallel flow pattern cooling system is relatively lower and not meet the velocity requirements of 1.5 m/s. Through the improvement of pump performance, the system coolant flowrate in parallel flow pattern cooling system can be increased to 90 L/min. After velocity uniformity improvement of water jacket, the coolant velocity distributions in parallel flow cooling system become more uniform. Coolant velocity and heat transfer coefficient of high temperature area both meet the design requirements of coolant velocity 1.5 m/s and heat transfer coefficients of 5000 W/(m2·K). The cooling performance for the engine with parallel flow pattern cooling system is significantly improved and meets the cooling design requirements. [ABSTRACT FROM AUTHOR]

Achieving an optimal cooling of the generator unit is indispensable for high working performance. In this work, computational fluid dynamics analysis on the flow field of the conventional type and silent type of the S688CCS series generator unit is conducted, and design optimization of the generator unit with poor cooling is studied based on flow field analysis results. Flow field simulation results indicate that the total cooling air quantity of the silent type generator unit is lower than that of the conventional type generator unit, and the cooling air quantity of the radiator is also lower than that of the conventional type generator unit, which is not conductive for the cooling of the silent type generator unit. The flow field optimization is achieved by adopting the single variable control method to improve the structure of the fan cover, silent components for silence, adjacent structure, and air inlet grille. The corresponding structure optimization scheme is put forward. After optimization, the air quantity for the cooling radiator of the silent type generator unit is 44.33% higher than that of its original structure, and the total cooling air quantity is higher than that of the conventional type generator unit. The research results in this work can provide a theoretical basis for the design of the cooling air flow path of generator units for achieving an optimal cooling performance. [ABSTRACT FROM AUTHOR]