On Natural Convective Heat Transfer in Vertical Channels With a Single Surface Mounted Heat-Flux Module

2003 ◽  
Vol 125 (4) ◽  
pp. 734-739 ◽  
Author(s):  
G. Desrayaud ◽  
A. Fichera
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Flow Characteristics ◽  
Vertical Channel ◽  
Numerical Data ◽  
Two Dimensional ◽  
Electronic Components ◽  
Adiabatic Wall ◽  
Numerical Predictions ◽  
Fluid Flow Characteristics

This paper presents the numerical predictions of heat transfer and fluid flow characteristics for natural convection in a vertical channel with two-dimensional protruding heat-flux module as applied to the cooling of electronic components. The investigation is for a configuration consisting of a single module mounted on a vertical adiabatic wall. An attempt was made to combine the temperature of the module for all the dimensions of the module into a single composite correlation, along with the numerical data.

scholarly journals Influence of fluid flow characteristics and heat transfer in a tube heat exchanger using H-shape inserts with circular ring

2021 ◽  
Author(s):  
Satyendra Singh ◽  
◽  
Tarun Joshi ◽  
Himanshi Kharkwal ◽  
◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Flow Characteristics ◽  
Circular Ring ◽  
Main Section ◽  
Tube Heat Exchanger ◽  
Fluid Flow Characteristics

The heat transfer and fluid flow characteristics in a tube heat exchanger using H-shape inserts with circular ring (CRWHS) has been done by computationally and experimentally. In this investigation parameters like ratio of the diameters and pitches are considered. The value of diameter and pitch ratios are (DR=0.8, 0.9), (PR=3, 4) respectively. The main section in which investigation was done is 1.5m long and the hydraulic diameter of the tube is 68.1mm. 1000 W/m2 heat flux was provided in the main section. Heat flux was constant throughout the investigation. Air is used as a working medium in which 6000 to 21000 Reynolds number was used for the investigation. The observation revealed that the increment in heat transfer rate is 4.56 times as compare to smooth tube for the circular ring with H-shape inserts. In case of DR=0.8 and PR=3, maximum thermal performance factor was obtain which is 3.24. In GIT the deviation in Nusselt number & friction factor is limited to ±0.4% & ±0.1% respectively. CFD analysis result comparisons with experimental one are presented in which the maximum deviations for thermal performance factor are limited to ±3.6%.

Heat Transfer and Fluid Flow Characteristics of One Side Heated Vertical Rectangular Channel Inserting Porous Material

2016 ◽  
Author(s):  
Takumi Shigematsu ◽  
Tetsuaki Takeda ◽  
Shumpei Funatani
Keyword(s):  
Heat Transfer ◽  
Porous Material ◽  
Cooling System ◽  
Natural Circulation ◽  
Rectangular Channel ◽  
Flow Characteristics ◽  
Vertical Channel ◽  
Passive Cooling ◽  
Fluid Flow Characteristics ◽  
Passive Cooling System

The Very High Temperature Reactor (VHTR) is a next generation nuclear reactor system. The passive cooling system should be designed for the VHTR as the best way of reactor vessel cooling system (VCS). Therefore, the gas cooling system with natural circulation is considered as a candidate for the VCS of the VHTR. Furthermore, we examined the heat transfer of rectangular vertical channel using “Spandrel” panel. “Spandrel” is the metallic plate having grooved patterns. The reason is that we can set it at low cost to the VCS because it is a kind of general construction materials. The objective of this study is to examine heat transfer characteristics of one side heated vertical rectangular channel with natural circulation and application of spandrel panel to the VCS of VHTR in order to construct the passive cooling system of the VHTR. We have performed an experiment and a numerical analysis. On experiment, we set the panel to adiabatic wall and supplied 100–400W/m2 heat flux to the panel. In order to obtain the heat transfer and fluid flow characteristics of a vertical channel inserting porous material, we have also carried out a numerical analysis using the commercial CFD code as the first step. From the results obtained in the analysis, it was found that the amount of heat removal was increased for 1–21% by inserting copper wires as porous material. This paper describes a thermal performance of the one-side heated vertical rectangular channel inserting copper wire with high porosity. From the view point of the economical and safety characteristic, the passive cooling system should be designed for the VTHR as the best way of the system. So, the gas cooling system by natural convection is the one of candidate system.

Numerical study on significance of wave amplitude, wavelength and aspect ratio on heat transfer and fluid flow characteristics in circular wavy MC heat sink design

2021 ◽  
pp. 095440622198937
Author(s):  
Valaparla Ranjith Kumar ◽  
Karthik Balasubramanian ◽  
K Kiran Kumar
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Fluid Flow ◽  
Aspect Ratio ◽  
Wave Amplitude ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Uniform Heat Flux ◽  
Uniform Heat ◽  
Fluid Flow Characteristics

In this study, hydrothermal characteristics in a circular wavy microchannel (CWMC) design under laminar flow conditions with uniform heat flux is numerically studied. Parametric studies in an innovative CWMC design were carried out at various wave amplitudes, wavelengths and aspect ratios. Three dimensional numerical study was performed in the Reynolds number (Re) range from 100 to 300 with uniform heat flux (50 W/cm2) applied at bottom of the channel, treating copper as channel material and water as working fluid. The obtained results were compared to sinusoidal wavy microchannel (SWMC).The results showed that heat transfer and fluid flow characteristics were significantly influenced by wave amplitude, wavelength and aspect ratio. Velocity vectors and contours were presented to understand the heat transfer and fluid flow characteristics. Stream-wise local Nusselt number, overall performance factor, span-wise velocity and temperature variation are also presented. It is concluded that CWMC with higher wave amplitude, smaller wave length and smaller aspect ratio gives higher heat transfer augmentation with corresponding pressure drop penalty.

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