Experimental investigation on the thermal performance of a light emitting diode headlamp with a flexible woven heat sink

Flexible woven heat sink (FWHS) is proposed to meet the heat-dissipation demand of a light emitting diode headlamp, which can be installed in limited spaces. The heat sink comprises three copper belts manufactured by weaving copper wires, with a structural advantage of high flexibility. The thermal resistance network model of the headlamp with the FWHS was established. A test system was implemented to analyze the factors affecting the heat transfer, such as the expanded forms, input power, ambient temperature, and wind speed. The expanded form of the FWHS can be adjusted by changing the inclination angles alpha and beta. alpha means the inclined angle between the adjacent woven belts, and beta means the inclined angle of each woven belt expanded along the folding part. The optimal expanded form is the status with alpha = 25-90 degrees and beta = 25-40 degrees. The overall temperature of the headlamp increases almost linearly with the increase in the input power and the ambient temperature. The cooling effect of the FWHS is enhanced with the increase in the wind speed; the optimal wind speed is approximately 2 m/s. (C) 2017 Elsevier Ltd. All rights reserved.