Coherent Vortical Structures and Their Relation to Hot/Cold Spots in a Thermal Turbulent Channel Flow
School of Mechanical Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47907, USA
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Received: 22 December 2017 / Revised: 31 January 2018 / Accepted: 4 February 2018 / Published: 8 February 2018
Direct numerical simulations of a turbulent channel flow with a passive scalar at
with blowing perturbations is carried out. The blowing is imposed through five spanwise jets located near the upstream end of the channel. Behind the blowing jets (about
, where D
is the jet diameter), we observe regions of reversed flow responsible for the high temperature region at the wall: hot spots that contribute to further heating of the wall. In between the jets, low pressure regions accelerate the flow, creating long, thin, streaky structures. These structures contribute to the high temperature region near the wall. At the far downstream of the jet (about
), flow instabilities (high shear) created by the blowing generate coherent vortical structures. These structures move hot fluid near the wall to the outer region of the channel; thereby, these are responsible for cooling of the wall. Thus, for engineering applications where cooling of the wall is necessary, it is critical to promote the generation of coherent structures near the wall.
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Dharmarathne, S.; Pulletikurthi, V.; Castillo, L. Coherent Vortical Structures and Their Relation to Hot/Cold Spots in a Thermal Turbulent Channel Flow. Fluids 2018, 3, 14.
Dharmarathne S, Pulletikurthi V, Castillo L. Coherent Vortical Structures and Their Relation to Hot/Cold Spots in a Thermal Turbulent Channel Flow. Fluids. 2018; 3(1):14.
Dharmarathne, Suranga; Pulletikurthi, Venkatesh; Castillo, Luciano. 2018. "Coherent Vortical Structures and Their Relation to Hot/Cold Spots in a Thermal Turbulent Channel Flow." Fluids 3, no. 1: 14.
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