scholarly journals Experimental Study on the Improvement of the Thermal Behavior of Electric Motors

2015 ◽  
Vol 09 (2) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Heat Dissipation ◽  
Spray Cooling ◽  
Electric Motors ◽  
Stator Windings ◽  
Air Convection ◽  
Free Air ◽  
Liquid Part ◽  
Coil Winding

The objective of this work is the improvement of the heat dissipation and the cooling of electric motors intended for the traction of vehicles. Two ways of improvement are proposed. The first one consists in replacing the air surrounding the stator windings by resins of higher thermal conductivity. The second way consists in using the spray cooling technique to cool the hottest parts of electric motor, i.e. coil windings. The two solutions are tested independently and simultaneously. Results show that filling the coil windings with resin enables better heat dissipation in the case of basic cooling by free air convection. On the contrary, the lowest temperatures are obtained with traditional coil winding without resin and by using spray cooling. In that case, the liquid part of the spray may infiltrate inside the coil and the evaporation takes place at the hottest point.

scholarly journals An experimental study of the motion of ice past obstacles by the process of regelation

1976 ◽  
Vol 17 (75) ◽  
pp. 79-98 ◽  
Author(s):  
E. M. Morris
Keyword(s):  
Thermal Conductivity ◽  
Experimental Study ◽  
Cross Sections ◽  
Transition Point ◽  
Water Layer ◽  
Single Object ◽  
Two Systems ◽  
Basal Sliding

AbstractThe results of regelation experiments, in which a single object is pulled through ice, cannot be applied directly to the problem of basal sliding in glaciers because the two systems have different geometries. When the force applied to a single object is small, impurities trapped in the regelation water-layer around the object inhibit the regelation process. At larger forces, above the Drake-Shreve transition point, impurities are shed in a trace behind the object. However, when ice moves over a series of obstacles a trace may exist above and below the transition point. The regelation velocity below the transition point is not reduced by the effect of trapped impurities. In an experiment in which brass cylingerrs of various cross-sections rotate in ice, the ratio between the expected regelation velocity, calculated using the basal-sliding theory of Nye, and the measured regelation velocity is 8±2, both above and below the transition point. The same ratio has been obtained by other workers with wires of similar thermal conductivity above the transition point. Measurements of température differences indicate that supercooling cannot be the main source of the unexpectedly low regelation velocities above the transition point.

Design and experimental study on a new heat dissipation method for watch-phones

2021 ◽  
Author(s):  
Wenjie Zhou ◽  
Yong Li ◽  
Zhaoshu Chen ◽  
Yuying Yan ◽  
Hanyin Chen
Keyword(s):  
Experimental Study ◽  
Heat Dissipation
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