G0600102 Study on Heat Transfer and Fluid Flow Characteristics of Vertical Rectangular Channel having Grooved Pattern : Effect in promoting heat transfer rate by forced convection

2015 ◽  
Vol 2015 (0) ◽  
pp. _G0600102--_G0600102-
Author(s):  
Takumi SHIGEMATSU ◽  
Shumpei FUNATANI ◽  
Tetsuaki TAKEDA
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Forced Convection ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Rectangular Channel ◽  
Flow Characteristics ◽  
Pattern Effect ◽  
Fluid Flow Characteristics

Effect of fin and tube configuration on heat transfer of an internally finned tube

2015 ◽  
Vol 25 (8) ◽  
pp. 1978-1999 ◽  
Author(s):  
Kailash Mohapatra ◽  
Dipti Prasad Mishra
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Transfer Rate ◽  
Flow Characteristics ◽  
Finned Tube ◽  
Maximum Heat ◽  
Content Type ◽  
Maximum Heat Transfer ◽  
Internally Finned Tube ◽  
Fluid Flow Characteristics

Purpose – The purpose of this paper is to determine the heat transfer and fluid flow characteristics of an internally finned tube for different flow conditions. Design/methodology/approach – Numerical investigation have been performed by solving the conservation equations of mass, momentum, energy with two equation-based k-eps model to determine the wall temperature, outlet temperature and Nusselt number of an internally finned tube. Findings – It has been found from the numerically investigation that there exists an optimum fin height and fin number for maximum heat transfer. It was also found that the heat transfer in T-shaped fin was highest compared to other shape. The saw type fins had a higher heat transfer rate compared to the plane rectangular fins having same surface area and the heat transfer rate was increasing with teeth number. Keeping the surface area constant, the shape of the duct was changed from cylindrical to other shape and it was found that the heat transfer was highest for frustum shape compared to other shape. Practical implications – The present computations could be used to predict the heat transfer and fluid flow characteristics of an internal finned tube specifically used in chemical and power plants. Originality/value – The original contribution of the paper was in the use of the two equation-based k-eps turbulent model to predict the maximum heat transfer through optimum design of fins and duct.

Heat Transfer and Fluid Flow Characteristics of a Turbulent Dual Jet Impinging on a Wavy Surface

2020 ◽  
Vol 12 (4) ◽  
Author(s):  
Tej Pratap Singh ◽  
Amitesh Kumar ◽  
Ashok Kumar Satapathy
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Flow Characteristics ◽  
Thermal Characteristics ◽  
Wavy Surface ◽  
Bottom Wall ◽  
Recirculation Region ◽  
Flow Strength

Abstract A simple and effective technique is proposed to enhance the heat transfer rate significantly. The current study deals with the analysis of a fluid flow and thermal characteristics of a turbulent dual jet impinging on a wavy surface. The surface area of the wall has been varied by considering different wavy profiles. The amplitude of the wavy surface is varied between 0.1 and 0.7 with an interval of 0.1. The number of cycles and the offset ratio (OR) are fixed to 10 and 7, respectively, thus, providing a complete parametric analysis of flow characteristics and thermal characteristics of the turbulent dual jet. The decay of maximum streamwise velocity, the variation of bottom wall pressure, and the variation of local heat flux and local Nusselt number have been computed. The variation of the bottom wall temperature for adiabatic wavy wall boundary condition for various amplitudes are also presented in this paper. It is found that the pressure decreases in the recirculation region when the amplitude increases. There is a sudden drop in pressure in the recirculation region when the wavy surface is present as compared with the dual jet with a plane wall surface and this drop goes on increasing as the amplitude increases. The wavy surface provides a favorable condition for the flow which results in the increased flow strength. The increase in the flow strength ultimately enhances the heat transfer rate. But, the increase in heat transfer is not monotonous. The heat transfer rate increases till the amplitude 0.5 thereafter it decreases. A maximum increase of 12% in the heat transfer rate is observed at A = 0.5. It is hoped that the present study opens a new line for the industries which deal with the cooling phenomenon.

Effects of Upstream Geometry on Natural Convection of a Darcian Fluid About a Semi-Infinite Inclined Heated Surface

1985 ◽  
Vol 107 (2) ◽  
pp. 283-292 ◽  
Author(s):  
C. T. Hsu ◽  
P. Cheng
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Natural Convection ◽  
Inclination Angle ◽  
Transfer Rate ◽  
Heated Surface ◽  
Flow Characteristics ◽  
Leading Edge ◽  
Fluid Flow Characteristics ◽  
Inclined Surface

The method of matched asymptotic expansions is applied to the problem of steady natural convection of a Darcian fluid about a semi-infinite inclined heated surface with a power law variation of wall temperature, i.e., Tˆwaxˆλ for xˆ≥0 where 0≤λ<1. The leading edge of the inclined surface intercepts at an angle, Λ0, with another impermeable unheated surface extending upstream. The effects of the inclination angle α0 (0 ≤ α0 < < π/2) of the heated surface as well as the upstream geometry at xˆ<0 (as specified by Λ0) on heat transfer and fluid flow characteristics near the heated surface are investigated. At a given inclination angle α0, it is found that heat transfer from an upward-facing heated inclined surface is larger than that of a downward-facing heated surface, and that decreasing the intercepting angle (Λ0) tends to lower the heat transfer rate. These effects become increasingly pronounced as the Rayleigh number is decreased.

scholarly journals Experimental Analysis of different shaped ribs on heat transfer and fluid flow characteristics

2020 ◽  
Vol 170 ◽  
pp. 01019
Author(s):  
Sandeep S Kore ◽  
Sunil V. Dingare ◽  
Satish Chinchanikar ◽  
Pravin Hujare ◽  
Ashok Mache
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Fluid Flow ◽  
Gas Turbines ◽  
Rectangular Channel ◽  
Flow Characteristics ◽  
Width Ratio ◽  
Internal Cooling ◽  
Fluid Flow Characteristics ◽  
Cooling Passage

There are number of applications such as gas turbines, solar air heating, electronics cooling and heat exchangers, where internal cooling passage is observed. For heat transfer augmentation inside these cooling passages different techniques are used like dimpled surface, wings and ribs. Ribs are used in most of the devices for internal cooling. The ribs disturb the boundary layer and increase the turbulent kinetic energy which enhances the heat transfer rate. Most of the researchers concentrate on square and rectangular shaped ribs. The cross section of the rib plays important role in the production of flow field. The shape of ribs affects on boundary layer separation, attachment and hot spots created. In the present paper heat transfer and fluid flow characteristics from rib roughened rectangular duct with different shapes of ribs were investigated. The experimental set up consists of rectangular channel of aspect ratio 4. The pitch to width ratio was varied as 5, 7.5 and 10 respectively. The Reynolds number was varied as 6000 to 30000. The ribs used for the investigations were square, house and boot shaped. From the investigations it is observed that boot shaped rib is having higher thermal performance than other two geometries

scholarly journals Heat Transmission Reinforcers Induced by MHD Hybrid Nanoparticles for Water/Water-EG Flowing over a Cylinder

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 623
Author(s):  
Firas A. Alwawi ◽  
Mohammed Z. Swalmeh ◽  
Amjad S. Qazaq ◽  
Ruwaidiah Idris
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Volume Fraction ◽  
Liquid Velocity ◽  
Flow Characteristics ◽  
Hybrid Nanoparticles ◽  
Critical Parameters ◽  
Heat Transmission ◽  
Constant Wall Temperature

The assumptions that form our focus in this study are water or water-ethylene glycol flowing around a horizontal cylinder, containing hybrid nanoparticles, affected by a magnetic force, and under a constant wall temperature, in addition to considering free convection. The Tiwari–Das model is employed to highlight the influence of the nanoparticles volume fraction on the flow characteristics. A numerical approximate technique called the Keller box method is implemented to obtain a solution to the physical model. The effects of some critical parameters related to heat transmission are also graphically examined and analyzed. The increase in the nanoparticle volume fraction increases the heat transfer rate and liquid velocity; the strength of the magnetic field has an adverse effect on liquid velocity, heat transfer, and skin friction. We find that cobalt nanoparticles provide more efficient support for the heat transfer rate of aluminum oxide than aluminum nanoparticles.

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