Thermo-hydraulic performances of internally finned tube with a new type wave fin arrays

A box-type wave absorber, which is composed of a perforated vertical front-wall and a perforated, horizontal bottom-wall, has been proved by a number of experiments to show lower coefficients of reflection and more distinguished reduction of wave pressures than the perforated vertical- wall breakwater. A breakwater of composite-type, which is 1500 m long and to be built at a water depth of 10 to 11 m below the Datum Line in the Port of Osaka, is being designed to set this new type of wave absorber in the concrete caissons of the vertical-walls which is named "a slit-type breakwater". The typical cross-section of the breakwater and the advantages of the slit-type breakwater are presented herein.

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Flow Analysis and Experimental Study on a Frost Reduction Method for Heat Exchangers

Korean Society of Technical Education and Training ◽

10.29279/kostet.2020.25.3.9 ◽

2020 ◽

Vol 25 (3) ◽

pp. 9-16

Author(s):

Gwon-Seok Sun

Keyword(s):

Experimental Study ◽

Heat Exchangers ◽

Reduction Method ◽

Cooling System ◽

Flow Analysis ◽

Finned Tube ◽

Cooling Efficiency ◽

Frost Formation ◽

Air Blast ◽

New Type

Frosting on the surface of a heat exchanger degrades its cooling efficiency in a cooling system. In this study, frost flow analysis is performed for frost reduction. A new type of air blast refrigerator is designed for reducing frost formation in its finned tube. Experimental results of the frost formation in the air blast refrigerator are presented. The main difference between the proposed and conventional air blast refrigerators is the flow of air through the finned tube. The proposed refrigerator produces less frost than the conventional refrigerators.

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

International Journal of Numerical Methods for Heat &amp Fluid Flow ◽

10.1108/hff-05-2014-0129 ◽

2015 ◽

Vol 25 (8) ◽

pp. 1978-1999 ◽

Cited By ~ 2

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.

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Thermal Optimization of an Internally Finned Tube Using Analytical Solutions Based on a Porous Medium Approach

Journal of Heat Transfer ◽

10.1115/1.2754866 ◽

2007 ◽

Vol 129 (10) ◽

pp. 1408-1416 ◽

Cited By ~ 7

Author(s):

Kyu Hyung Do ◽

Jung Yim Min ◽

Sung Jin Kim

Keyword(s):

Porous Medium ◽

Analytical Solutions ◽

Saturated Porous Medium ◽

Equation Model ◽

Finned Tube ◽

Navier Stokes ◽

Uniform Heat Flux ◽

Thermal Optimization ◽

Internally Finned Tube ◽

Cylindrical Region

The present work deals with thermal optimization of an internally finned tube having axial straight fins with axially uniform heat flux and peripherally uniform temperature at the wall. The physical domain was divided into two regions: One is the central cylindrical region of the fluid extending to the tips of the fins and the other constituted the remainder of the tube area. The latter region including the fins was modeled as a fluid-saturated porous medium. The Brinkman-extended Darcy equation for fluid flow and two-equation model for heat transfer were used in the porous region, while the classical Navier–Stokes and energy equations were used in the central cylindrical region. The analytical solutions for the velocity and temperature profiles were in close agreement with the corresponding numerical solution as well as with existing theoretical and experimental data. Finally, optimum conditions, where the thermal performance of the internally finned tube is maximized, were determined using the developed analytical solutions.

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Numerical Analysis of Mixed Convection through an Internally Finned Tube

Advances in Mechanical Engineering ◽

10.1155/2012/918342 ◽

2012 ◽

Vol 4 ◽

pp. 918342 ◽

Cited By ~ 4

Author(s):

Sachindra Kumar Rout ◽

Dipti Prasad Mishra ◽

Dhirendra Nath Thatoi ◽

Asit Ku. Acharya

Keyword(s):

Numerical Analysis ◽

Mixed Convection ◽

Finned Tube ◽

Internally Finned Tube

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Numerical Investigation of the Thermal Performance of an Axially Rotating Internally Finned Receiver Tube of Parabolic Trough Concentrator

WSEAS TRANSACTIONS ON POWER SYSTEMS ◽

10.37394/232016.2021.16.25 ◽

2021 ◽

Vol 16 ◽

pp. 241-253

Author(s):

Andrew S. Tanious ◽

Ahmed A. Abdel-Rehim

Keyword(s):

Thermal Performance ◽

Rotation Rate ◽

Pressure Coefficient ◽

Axial Rotation ◽

Finned Tube ◽

Outlet Temperature ◽

Parabolic Trough ◽

Ansys Fluent ◽

Fluid Layers ◽

Internally Finned Tube

Enhancement of the thermal performance of the parabolic trough receiver tube is one of the approaches to energy sustainability. In the present work, the thermal performance of an axially rotating receiver tube equipped with internal flat longitudinal fins is studied. The effects of both the fin height and the rate of axial rotation are investigated at low values of axial Reynold’s number. The numerical analysis is held at various rotation rates using ANSYS Fluent. The numerical findings showed that the effect of the axial rotation on the internally finned receiver tube is not significant yet negative where a maximum reduction of 6% in the outlet temperature is reached in the 2mm height internally finned tube at rotation rate of N=21. However, the analysis showed that as the rotation rate increases, the temperature homogeneity between the fluid layers also increases and thus the liquid stratification phenomenon between the fluid layers is eliminated. The percentage of temperature difference between the fluid layers near the pipe center and the layers near the pipe wall reaches an optimum value of 58.4% at N=21 which is confirmed by an optimum increase of 110% in Nusselt number at the same rotation rate. However, a maximum loss of 81.6% in pressure coefficient is found in the case of the 2mm internally finned tube due to the increased turbulence. Thus, the integration of pipe axial rotation and internal fins can yield an enhancement in the heat transfer to the parabolic trough concentrator receiver tube and thus its thermal performance.

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