TY - JOUR
AU - Karcher, Christian
AB - An experimental study on coupled heat transfer of natural convection and directed radiation is presented. These effects appear in automotive headlamps, for instance. To separate them, the pressure inside the enclosure is varied. As the Grashof number scales like Gr ∼ p2, upon decreasing pressure, convection is strongly suppressed while radiation remains unchanged. The experimental setup consists of a semi‐transparent lens and an automotive reflector arranged in a closed tube (300mm length, 180mm diameter). Almost all radiation from the lamp is directed from the reflector to the lens. There it is partly absorbed causing unfavourable hot spots. The location of these spots strongly depends on the interaction of convection and radiation. To improve the understanding of these effects, the location and the temperature of the spots were measured while varying the pressure from 102 to 105 Pa and the electrical power of the lamp from 10W to 15W, respectively. Besides, two different distances between the reflector and the lens were analysed. It was found that upon decreasing pressure, the hot spot temperature rises and the location moves closer to the optical axis of the reflector. Moreover, the wall temperature above the reflector decreases. The results will be compared with predictions of numerical simulations. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
TI - Influence of Varying Pressure on Natural Convection and Radiation Heat Transfer in an Enclosure
JF - Proceedings in Applied Mathematics and Mechanics
DO - 10.1002/pamm.200510264
DA - 2005-12-01
UR - https://www.deepdyve.com/lp/wiley/influence-of-varying-pressure-on-natural-convection-and-radiation-heat-BgD50NlIBO
SP - 575
EP - 576
VL - 5
IS - 1
DP - DeepDyve
ER -