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contributor authorKoffi, Moise
contributor authorAndreopoulos, Yiannis
contributor authorJiji, Latif M.
date accessioned2017-05-09T01:09:41Z
date available2017-05-09T01:09:41Z
date issued2014
identifier issn0022-1481
identifier otherht_136_10_101101.pdf
identifier urihttp://yetl.yabesh.ir/yetl/handle/yetl/155375
description abstractThe oscillatory rotational motion of the elephant pinna is considered a key mechanism in metabolic heat dissipation. Limited experimental investigations have revealed that the flapping of the elephant's pinna is responsible for surface heat transfer enhancement. The objective of the present experimental and computational work is to investigate the physics of the flow induced by the pinna's motion and its effects on the heat transfer. This was accomplished by designing, fabricating and testing two fullsize laboratory models of elephant pinnae: one rigid and one flexible, both instrumented with small size thermocouples for timedependent surface temperature measurements. A constant heat flux is applied to both sides of each model which is rotated about a fixed edge with a frequency of 2 rad/s in an infinite domain at ambient conditions. Of interest is the study of the impact of the flexural strength of the model's material on surface heat transfer. Additional computer simulations of the flow and thermal fields revealed a hookedshape vortex tube around the free edges of the flapping pinna. This result is confirmed by the flow visualization with smoke particles. Both experimental and computational results exhibit local surface temperature profiles characterized by a transient unsteady periodic variation followed by a steady periodic phase. Flow visualization indicated significant interaction between the vortical structures shed off the edge and the flexible model's boundary layer. It has been found that the cooling of the flexible model is enhanced by 30%.
publisherThe American Society of Mechanical Engineers (ASME)
titleThe Role of Pinnae Flapping Motion on Elephant Metabolic Heat Dissipation
typeJournal Paper
journal volume136
journal issue10
journal titleJournal of Heat Transfer
identifier doi10.1115/1.4027864
journal fristpage101101
journal lastpage101101
identifier eissn1528-8943
treeJournal of Heat Transfer:;2014:;volume( 136 ):;issue: 010
contenttypeFulltext


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