Effect of thermal boundary conditions on heat transfer performance of liquid‐liquid Taylor flow through a microchannel with obstruction

2021 ◽  
Author(s):  
Sankepally Chandrasekhar ◽  
Patel Akash ◽  
Vysyaraju Rajesh Khana Raju
Keyword(s):  
Heat Transfer ◽  
Boundary Conditions ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Taylor Flow ◽  
Thermal Boundary Conditions ◽  
Flow Through

Investigation of Heat Transfer Performances of Nanofluids Flow through a Circular Minichannel Heat Sink for Cooling of Electronics

2013 ◽  
Vol 832 ◽  
pp. 166-171
Author(s):  
M.R. Sohel ◽  
Saidur Rahman ◽  
Mohd Faizul Mohd Sabri ◽  
M.M. Elias ◽  
S.S. Khaleduzzaman
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Base Fluid ◽  
Heat Transfer Performance ◽  
Volume Fraction ◽  
Transfer Performance ◽  
Block Dimension ◽  
Electronic Heat ◽  
Flow Through ◽  
Cooling Of Electronics

Nanofluid is the suspension of nanoparticle in a base fluid. In this paper, the heat transfer performances of the nanofluids flow through a circular shaped copper minichannel heat sink are discussed analytically. Al2O3-water, CuO-water, Cu-water and Ag-water nanofluids were used in this analysis to make comparative study of their thermal performances. The hydraulic diameter of the minichannel is 500 μm and total block dimension is 50mm× 50mm× 4mm. The analysis is done at different volume fractions of the nanoparticle ranging from 0.5 vol.% to 4 vol.%. The results showed that the heat transfer performance increases significantly by the increasing of volume fraction of nanoparticle. Ag-water nanofluid shows the highest performance compared to the other nanofluids. So, this nanofluid can be recommended as a coolant flow through a circular minichannel for cooling of electronic heat sink.

Heat Transfer Performance of a Transonic Turbine Blade Passage in the Presence of Leakage Flow Through Upstream Slot and Mateface Gap With Endwall Contouring

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Arnab Roy ◽  
Sakshi Jain ◽  
Srinath V. Ekkad ◽  
Wing Ng ◽  
Andrew S. Lohaus ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Performance ◽  
Hot Spot ◽  
Suction Side ◽  
Common Source ◽  
Linear Regression Method ◽  
Leakage Flow ◽  
Transfer Performance ◽  
Blow Down ◽  
Flow Through

Comparison of heat transfer performance of a nonaxisymmetric contoured endwall to a planar baseline endwall in the presence of leakage flow through stator–rotor rim seal interface and mateface gap is reported in this paper. Heat transfer experiments were performed on a high turning turbine airfoil passage at Virginia Tech's transonic blow down cascade facility under design conditions for two leakage flow configurations—(1) mateface blowing only, (2) simultaneous coolant injection from the upstream slot and mateface gap. Coolant to mainstream mass flow ratios (MFRs) were 0.35% for mateface blowing only, whereas for combination blowing, a 1.0% MFR was chosen from upstream slot and 0.35% MFR from mateface. A common source of coolant supply to the upstream slot and mateface plenum made sure the coolant temperatures were identical at both upstream slot and mateface gap at the injection location. The contoured endwall geometry was generated to minimize secondary aerodynamic losses. Transient infrared thermography technique was used to measure endwall surface temperature and a linear regression method was developed for simultaneous calculation of heat transfer coefficient (HTC) and adiabatic cooling effectiveness, assuming a one-dimensional (1D) semi-infinite transient conduction. Results indicate reduction in local hot spot regions near suction side as well as area averaged HTC using the contoured endwall compared to baseline endwall for all coolant blowing cases. Contoured geometry also shows better coolant coverage further along the passage. Detailed interpretation of the heat transfer results along with near endwall flow physics has also been discussed.

Heat transfer performance for turbulent flow through a tube using double helical tape inserts

2012 ◽  
Vol 39 (6) ◽  
pp. 818-825 ◽  
Author(s):  
M.M.K. Bhuiya ◽  
M.S.U. Chowdhury ◽  
J.U. Ahamed ◽  
M.J.H. Khan ◽  
M.A.R. Sarkar ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Flow Through

Heat Transfer Performance of a Transonic Turbine Blade Passage in Presence of Leakage Flow Through Upstream Slot and Mateface Gap With Endwall Contouring

2014 ◽  
Author(s):  
Arnab Roy ◽  
Sakshi Jain ◽  
Srinath V. Ekkad ◽  
Wing F. Ng ◽  
Andrew S. Lohaus ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Performance ◽  
Hot Spot ◽  
Suction Side ◽  
Common Source ◽  
Linear Regression Method ◽  
Leakage Flow ◽  
Transfer Performance ◽  
Blow Down ◽  
Flow Through

Comparison of heat transfer performance of a non-axisymmetric contoured endwall to a planar baseline endwall in presence of leakage flow through stator-rotor rim seal interface and mateface gap is reported in this paper. Heat transfer experiments were performed on a high turning (∼127°) turbine airfoil passage at Virginia Tech’s transonic blow down cascade facility under design conditions (exit isentropic Mach number 0.88 and 0° incidence) for two leakage flow configurations — 1) mateface blowing only, 2) simultaneous coolant injection from the upstream slot as well as mateface gap. Coolant to mainstream mass flow ratios (MFR) were 0.35% for mateface blowing only, whereas for combination blowing, a 1.0% MFR was chosen from upstream slot and 0.35% MFR from mateface. A common source of coolant supply to the upstream slot and mateface plenum made sure the coolant temperatures were identical at both upstream slot and mateface gap at the injection location. The contoured endwall geometry was generated to minimize secondary aerodynamic losses. Transient IR (Infrared) thermography technique was used to measure endwall surface temperature and a linear regression method was developed for simultaneous calculation of heat transfer coefficient (HTC) and adiabatic cooling effectiveness (ETA), assuming a 1D semi-infinite transient conduction. Results indicate reduction in local hot spot regions near suction side as well as area averaged HTC using the contoured endwall compared to baseline endwall for all coolant blowing cases. Contoured geometry also shows better coolant coverage profiles further along the passage. Detailed interpretation of the heat transfer results along with near endwall flow physics has also been discussed.

Heat Transfer and Friction Loss in Laminar Radial Flows through Rotating Annular Disks

1981 ◽  
Vol 103 (2) ◽  
pp. 212-217 ◽  
Author(s):  
S. Mochizuki ◽  
Wen-Jei Yang
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Pressure Drop ◽  
Rotational Speed ◽  
Heat Transfer Performance ◽  
Radial Flow ◽  
Friction Loss ◽  
Transfer Performance ◽  
Flow Through ◽  
Annular Disks

Heat transfer and pressure drop performance are experimentally studied for laminar radial flow through a stack of corotating annular disks. The disk surfaces are heated by condensing steam to create constant surface temperature condition. The traditionally defined friction factor is modified to include the effect of centrifugal force induced by the rotation of the heat transfer surface on core pressure drop. Empirical equations are derived for the heat transfer and friction factors at zero rotational speed. Test results are obtained for various rotational speeds. It is disclosed that (1) The transition in the radial flow through rotating parallel disk passages occurs at the Reynolds number (based on the hydraulic diameter of the flow passage) of 3000 at which stall propagation occurs in the rotor. (2) In the laminar flow regime, its heat transfer performance at zero rotational speed is superior to forced convection in the triangular, square, annular, rectangular and parallel-plane geometries. (3) The effects of disk surface rotation are twofold: a significant augmentation in heat transfer accompanied by a very substantial reduction in friction loss. (4) These rotational effects decrease with an increase in the fluid flow rate until the transition Reynolds number where the effects of centrifugal and Coriolis forces diminish is reached. (5) Heat transfer performance at low through flows is superior to that of high-performance surfaces for compact heat exchangers.

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