TY - JOUR
T1 - Experimental and numerical local heat transfer study on micro pin fin with tip clearance
AU - Tabkhi, Hanieh
AU - Nayebzadeh, Arash
AU - Peles, Yoav
N1 - Funding Information:
This work was funded by the Office of Naval Research (ONR) with Dr. Mark Spector as program manager (Grant # N00014-15-1-2071 ). The authors would like to acknowledge the Cornell NanoScale Science& Technology Facility (CNF) for staff support.
Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2020/10
Y1 - 2020/10
N2 - Fluid flow and local heat transfer in a microchannel with a 150-µm diameter pin fin with a tip clearance were experimentally and numerically studied for three Reynolds numbers in laminar regime. Tip clearances of 0, 30, 45 and 100 µm in a 200-µm high microchannel. Experimental and numerical local temperatures and the corresponding Nusselt numbers along the centerline of the pin fin were presented and discussed. Local temperatures were measured on top of the heater surface and downstream the pin fin through micro resistance temperature detectors (RTDs). A conjugate CFD modeling capable of simulating solid/fluid conduction and convection revealed velocity, heat flux and heat transfer coefficient over the heated surface. Nusselt number and wake length for a range of tip clearances were presented and compared with full-height pin fin. Experimental and numerical results showed that a tip clearance can significantly enhance heat transfer in the wake region. Simulations revealed that tip clearance alters the flow structure by increasing the three dimensionality of the flow, promoting mixing, shortening the wake region, and increasing the velocity downstream the pin fin. A tip clearance with a height of 100 µm was found to provide the best heat transfer enhancement.
AB - Fluid flow and local heat transfer in a microchannel with a 150-µm diameter pin fin with a tip clearance were experimentally and numerically studied for three Reynolds numbers in laminar regime. Tip clearances of 0, 30, 45 and 100 µm in a 200-µm high microchannel. Experimental and numerical local temperatures and the corresponding Nusselt numbers along the centerline of the pin fin were presented and discussed. Local temperatures were measured on top of the heater surface and downstream the pin fin through micro resistance temperature detectors (RTDs). A conjugate CFD modeling capable of simulating solid/fluid conduction and convection revealed velocity, heat flux and heat transfer coefficient over the heated surface. Nusselt number and wake length for a range of tip clearances were presented and compared with full-height pin fin. Experimental and numerical results showed that a tip clearance can significantly enhance heat transfer in the wake region. Simulations revealed that tip clearance alters the flow structure by increasing the three dimensionality of the flow, promoting mixing, shortening the wake region, and increasing the velocity downstream the pin fin. A tip clearance with a height of 100 µm was found to provide the best heat transfer enhancement.
UR - http://www.scopus.com/inward/record.url?scp=85088814000&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85088814000&partnerID=8YFLogxK
U2 - 10.1016/j.applthermaleng.2020.115756
DO - 10.1016/j.applthermaleng.2020.115756
M3 - Article
AN - SCOPUS:85088814000
VL - 179
JO - Journal of Heat Recovery Systems
JF - Journal of Heat Recovery Systems
SN - 1359-4311
M1 - 115756
ER -