HEAT TRANSFER AND FRICTION LOSS IN FLOWS NORMAL TO STACKS OF PERFORATED PLATES

1978 ◽  
Author(s):  
C.P. Lee ◽  
Wen-Jei Yang
Keyword(s):  
Heat Transfer ◽  
Friction Loss ◽  
Perforated Plates

Characterization of heat transfer and friction loss of water turbulent flow in a narrow rectangular duct under 25–40 kHz ultrasonic waves

Ultrasonics ◽  
2021 ◽  
Vol 114 ◽  
pp. 106366
Author(s):  
Korpong Viriyananon ◽  
Jirachai Mingbunjerdsuk ◽  
Teerapat Thungthong ◽  
Weerachai Chaiworapuek
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Ultrasonic Waves ◽  
Friction Loss ◽  
Rectangular Duct

scholarly journals Experimental Study of Heat Transfer Enhancement and Friction Loss Induced by Inserted Rotor-assembled Strand (I) Water

2008 ◽  
Vol 16 (6) ◽  
pp. 849-855 ◽  
Author(s):  
Pengcheng XIE ◽  
Fengxiang LI ◽  
Yumei DING ◽  
Hua YAN ◽  
Changfeng GUAN ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Transfer Enhancement ◽  
Friction Loss ◽  
Transfer Enhancement

Preliminary Evaluation of Turbulence Level Influence in Heat Transfer Measurements

2004 ◽  
Author(s):  
Carlo Carcasci ◽  
Luca Innocenti ◽  
Marco Surace
Keyword(s):  
Heat Transfer ◽  
Initial Level ◽  
Measurement Techniques ◽  
Preliminary Evaluation ◽  
Turbulence Level ◽  
Hot Wire ◽  
Aluminum Foams ◽  
Transfer Coefficients ◽  
Perforated Plates ◽  
Heat Transfer Coefficients

Heat transfer coefficients have often been experimentally measured, taking into account Nusselt number as a function of Reynolds and Prandtl number. Most experimenters spend their effort to control turbulence level, set it to different values, or keep it unchanged during the tests, as it’s not easy to predict how its initial level may change final results. The aim of this work is to add some comprehension on how different turbulence incoming levels may affect heat transfer measurements, and when it’s possible or not to neglect such effects. Experimental setup features different duct geometries, and thermocromic liquid crystals coupled with hot-wire anemometers are used as main measurement techniques. Tests were performed for Reynolds number from 10000 to 50000 and turbulence level from 3% to 12%. Several turbulence manipulators were adopted, including aluminum foams and multi-perforated plates, and results show some interesting dependences of heat transfer from both turbulence level and grid features.

Friction Loss and Heat Transfer of Fibre and Wood Pulp Suspensions: A Review

2018 ◽  
Author(s):  
Shirin Ghatrehsamani ◽  
Yiannis Ampatzidis ◽  
Sahar Ghatrehsamani
Keyword(s):  
Heat Transfer ◽  
Wood Pulp ◽  
Friction Loss ◽  
Pulp Suspensions

scholarly journals An Experimentally Validated Numerical Modeling Technique for Perforated Plate Heat Exchangers

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
M. J. White ◽  
G. F. Nellis ◽  
S. A. Klein ◽  
W. Zhu ◽  
Y. Gianchandani
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Numerical Model ◽  
Heat Exchangers ◽  
Perforated Plate ◽  
Plate Heat Exchanger ◽  
Internal Temperature ◽  
Perforated Plates ◽  
Axial Conduction ◽  
Plate Heat

Cryogenic and high-temperature systems often require compact heat exchangers with a high resistance to axial conduction in order to control the heat transfer induced by axial temperature differences. One attractive design for such applications is a perforated plate heat exchanger that utilizes high conductivity perforated plates to provide the stream-to-stream heat transfer and low conductivity spacers to prevent axial conduction between the perforated plates. This paper presents a numerical model of a perforated plate heat exchanger that accounts for axial conduction, external parasitic heat loads, variable fluid and material properties, and conduction to and from the ends of the heat exchanger. The numerical model is validated by experimentally testing several perforated plate heat exchangers that are fabricated using microelectromechanical systems based manufacturing methods. This type of heat exchanger was investigated for potential use in a cryosurgical probe. One of these heat exchangers included perforated plates with integrated platinum resistance thermometers. These plates provided in situ measurements of the internal temperature distribution in addition to the temperature, pressure, and flow rate measured at the inlet and exit ports of the device. The platinum wires were deposited between the fluid passages on the perforated plate and are used to measure the temperature at the interface between the wall material and the flowing fluid. The experimental testing demonstrates the ability of the numerical model to accurately predict both the overall performance and the internal temperature distribution of perforated plate heat exchangers over a range of geometry and operating conditions. The parameters that were varied include the axial length, temperature range, mass flow rate, and working fluid.

Analysis of Fluid Flow and Heat Transfer in Corrugated Perforated Plate Fin Heat Sinks

2021 ◽  
pp. 1-30
Author(s):  
Shripad A Upalkar ◽  
Saksham Gakhar ◽  
Shankar Krishnan
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Heat Dissipation ◽  
Single Channel ◽  
Perforated Plate ◽  
Flow Characteristics ◽  
Flow Distribution ◽  
Optimum Number ◽  
Perforated Plates ◽  
Optimum Diameter

Abstract This paper reports a mathematical model for predicting the fluid and heat flow characteristics of a Z-shaped corrugated perforated plate heat sink. Experiments were carried out to validate overall pressure drop as well as heat transfer predictions. A two-pronged approach was undertaken to design a corrugated perforated fin geometry: (a) macroscopic packaging, where the flow is distributed into conduits before being fed into perforated plates, and (b) microscopic design, where the pores are sized to maximize heat dissipation. A methodology typically used for predicting flow maldistribution is extended for packaging porous perforated plates in the macroscopic approach. An illustrative study is carried that estimates the optimum number of porous perforated plate fins that can be packaged within a given volume under fixed pressure drop constraint. In the microscopic approach, an order of magnitude analysis was carried out to decide the optimum diameter to maximize the heat transfer rate and expression for optimum diameter, and maximum achievable heat flux is proposed. Numerical simulations were carried out by considering full perforated plate porous fin geometry and single-channel geometry, and good agreement in their results was found. Finally, this study elaborates on the importance of achieving uniform flow distribution across the porous perforated plate fins.

Heat Transfer Enhancement of Impingement Cooling by Different Crossflow Diverters

2021 ◽  
Author(s):  
Juan He ◽  
Qinghua Deng ◽  
Kun Xiao ◽  
Zhenping Feng
Keyword(s):  
Heat Transfer ◽  
Velocity Ratio ◽  
Three Dimensional ◽  
Local Heat ◽  
Friction Loss ◽  
Navier Stokes ◽  
Impingement Cooling ◽  
Streamwise Location ◽  
Overall Evaluation ◽  
The Cost

Abstract Impingement cooling can effectively disperse local heat load, but its downstream heat transfer is always reduced due to crossflow effect. In this study, the flow and heat transfer characteristics of impingement cooling with Semi-Circular (SC), Semi-Rectangular (SR), Semi-Diamond (SD) and Semi-Four-pointed Star (SFS) crossflow diverters are compared over the ReD ranging from 3,500 to 14,000 by solving three dimensional Reynolds-Averaged Navier-Stokes (RANS) equations with SST k-? turbulence model. It is found that crossflow diverters change the distribution of local jet Reynolds number (ReD,j/ReD) and reduce the mass velocity ratio of downstream crossflow to jet (Gcf/Gj), so they enhance the heat transfer significantly, but also come at the cost of friction loss. Overall evaluation reveals that various crossflow diverters can improve the comprehensive heat transfer performance parameter (F), and the maximum increases are 11.0%, 14.3%, 12.2% and 14.7% for SC, SR, SD and SFS cases respectively. It is noted that the Nusselt number of heated SFS-shaped diverter surface is also the highest. Besides, the influences of streamwise location (L) and thickness (t) of SFS-shaped diverter are also investigated. Results show that the heat transfer and friction loss change a little when the L increases from 2D to 3D, but the heat transfer decreases sharply and friction loss increases seriously when the L increases from 3D to 4D. With respect to the t, it has almost no effect on the flow field and heat transfer.

Experimental Investigation to Evaluate the Optimum Performance of Helical Coiled Tube with Insert and Nano-Fluid

2014 ◽  
Vol 1036 ◽  
pp. 89-94
Author(s):  
Saleh Mahdi Qasim ◽  
Sahar A. Fattah ◽  
Osama M. Jassim
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Nusselt Number ◽  
Swirl Flow ◽  
Friction Loss ◽  
Test Fluid ◽  
Dean Number ◽  
Coiled Tube ◽  
Helical Tube ◽  
Wire Coil

In the present work an experimental investigation is carried out to evaluate the performance of helical coiled tube with the swirl flow device using Al2O3nanofluid.The effects of wire coil insert with different parameter on heat transfer and friction loss in the helical tube were examined with Dean number (De) ranging from 700 to 2000. The circular or square coil wire has different cross sections, insertedin the tube with different pitch. The wire coil with Al2O3 nanoparticles with a diameter of 80nm dispersed in distilled water with volume concentrations of (0.08,0.1, 0.2and 0.3 vol.% ) were used as the test fluid. The effects of Dean Number, volume concentration of suspended nanoparticles, and wire coil on heat characteristics were investigated. The results reveal that the use of tabulators leads to a considerable increase in heat transfer and friction loss over those of a smooth tube. The Nusselt number increases with increasing of Dean number and reduction in pitch of wire coil. The square type of wire coil provides slightly higher heat transfer than the circular under the same conditions. Results show that the optimum heat transfer is caused of P=15mm of wire coils. Adding nanoparticles to the base fluid causes a significant enhancement in heat transfer characteristics. The overall enhancement in heat transfer using two mechanisms simultaneously compared to using pure fluid within the smooth helical tube exceeds over 213.2% (180% spring enhancement +33.2%Al2O3). The optimum results were found to be P=15mm, φ=0. 3Al2O3 t=2mm square cross section and De=1889. Finally, empirical correlations are developed of predicting Nusselt number of the flow with and without nanofluid. Comparison between the present result in reference results show good agreement.

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