Open AccessThermal-hydrodynamic design of energy-efficient surfaces with inclined oval-trench vortex generators
Author(s) -
С. А. Исаев
Publication year - 2019
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1359/1/012002
Subject(s) - dimple , turbulence , vortex , mechanics , trench , materials science , heat transfer , nusselt number , flow (mathematics) , channel (broadcasting) , thermal , heat transfer enhancement , plane (geometry) , optics , geometry , physics , meteorology , reynolds number , composite material , engineering , electrical engineering , mathematics , layer (electronics)
In the present study it is found that enhancement of air turbulent flow and heat transfer at Re=10 4 is influenced by a set of one-row oval-trench dimples of depth 0.25 inclined at an angle of 65 ° to the incoming flow and located at the heated wall of the rectangular (9×1) narrow channel when the dimple step H is varied. The periodic section of the dimpled channel 8 in length is considered. The dimple step H is varied from 8 to 2. Abnormal enhancement of flow and heat transfer at H =2 is followed by both a 4-fold decrease in relative negative friction and a 6.5-fold increase in relative heat transfer in the separated flow zone. The phenomenon of turbulent flow acceleration with a 1.39-fold increase in the maximum flow velocity (at H =2) in the dimpled narrow channel in comparison to the plane-parallel channel is discovered.