Gundabattini, Edison, Kuppan, Ravi, Solomon, Darius Gnanaraj, Kalam, Akhtar, Kothari, D.P., and Abu Bakar, Rosli
Subjects
PHASE change materials, HEAT pipes, INDUCTION motors, ELECTRIC machinery, ELECTRIC motors, TEMPERATURE distribution, TEMPERATURE effect, ELECTRIC machines
Abstract
Performance of electric motors and losses in terms of heat and temperature are reviewed in this paper. Airgap eccentricity, electromagnetic performance, effect of temperature and losses are shown as factors affecting the efficiency. Several methods of computer aided analyses are listed. Temperature distribution in an induction motor is shown through the results of a simulation. Different cooling methods are reviewed. Future directions for research include cryogenic cooling, heat pipes and usage of phase change materials. [ABSTRACT FROM AUTHOR]
Abstract: In this paper, heat transfer performance of a 40cm-length circular heat pipe with screen mesh wick is experimentally investigated. This heat pipe is made of copper with two diameters; larger in the evaporator and smaller in the adiabatic and condenser. Three different liquids including water, methanol, and ethanol are separately filled within the heat pipe. Low heat fluxes are applied (up to 2500W/m2) in the evaporator and constant temperature water bath is used at three levels including 15, 25, and 35°C in the condenser. Results demonstrate that higher heat transfer coefficients are obtained for water and ethanol in comparison with methanol. Furthermore, increasing heat flux increases the evaporator heat transfer coefficient. For the case of methanol, some degradation in heat transfer coefficient is occurred at high heat fluxes which can be due to the surface dryout effect. Increasing the inclination angle decreases the heat pipe thermal resistance. [Copyright &y& Elsevier]
Abstract: The goal of this paper is to experimentally study the behavior of nanofluid to improve the performance of a circular heat pipe. Pure water and Al2O3-water based nanofluid are used as working fluids. An experimental setup is designed and constructed to study the heat pipe performance under different operating conditions. The effect of filling ratio, volume fraction of nano-particles in the base fluid, and heat input rate on the thermal resistance is investigated. Total thermal resistance of the heat pipe for pure water and Al2O3-water based nanofluid is also predicted. An experimental correlation is obtained to predict the influence of Prandtl number and dimensionless heat transfer rate, K q on thermal resistance. Thermal resistance decreases with increasing Al2O3-water based nanofluid compared to that of pure water. The experimental data is compared to the available data from previous work. The agreement is found to be fairly good. [ABSTRACT FROM AUTHOR]