Natural Convection Heat Transfer from Arrays of Horizontal Cylinders-numerical and Experimental

Natural Convection Heat Transfer from Arrays of Horizontal Cylinders-numerical and Experimental PDF Author: Carol Elizabeth Stephens
Publisher:
ISBN:
Category : Cylinders
Languages : en
Pages : 254

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Natural Convection Heat Transfer from Arrays of Horizontal Cylinders-numerical and Experimental

Natural Convection Heat Transfer from Arrays of Horizontal Cylinders-numerical and Experimental PDF Author: Carol Elizabeth Stephens
Publisher:
ISBN:
Category : Cylinders
Languages : en
Pages : 254

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An Experimental Study of Natural Convection Heat Transfer from a Horizontal Cylinder Array Vertically Aligned to and Confined by a Single Wall and Two Walls

An Experimental Study of Natural Convection Heat Transfer from a Horizontal Cylinder Array Vertically Aligned to and Confined by a Single Wall and Two Walls PDF Author: Thamir R. Al-Alusi
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 448

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Book Description
Convection heat transfer was experimentally investigated for two different geometries. One case had three horizontal cylinders in a vertical plane placed between two vertical walls. The second case had three horizontal cylinders in a vertical plane with only one vertical wall. Several different cylinder center-tocenter spacings were investigated. The wall spacings for the two wall and single wall cases were also varied. The cylinders were placed in a still air medium at atmospheric pressure and were maintained at a constant heat flux. The modified Rayleigh number, based on the diameter of the cylinders, ranged from 6.2 x 104 to 1.2 x 106. A scale analysis was performed to predict the relationship between the Nusselt number and the modified Rayleigh number. A standard finite-difference code was employed to show the temperature distribution and velocity vectors distribution around the cylinders. The results showed that there was a maximum heat transfer from each cylinder at a specific wall-array spacing and a specific center-to-center spacing. Comparisons of heat transfer results with a single free cylinder and a free array of horizontal cylinders were made and discussed. Empirical equations were proposed to predict the effects of the experimental parameters on the heat transfer as expressed by the average Nusselt number of each cylinder or the average Nusselt number of the whole array. Flow visualization was accomplished using laser sheets. The resulting studies showed that the presence of a single wall or the asymmetrical placement of the array between the two walls eliminated the presence of the vortices in the spaces between the cylinders and displaced the stagnation points. The asymmetrical placement of the array between two walls created a reversed current between the two walls.

Natural Convective Heat Transfer from Short Inclined Cylinders

Natural Convective Heat Transfer from Short Inclined Cylinders PDF Author: Patrick H. Oosthuizen
Publisher: Springer Science & Business Media
ISBN: 3319024590
Category : Science
Languages : en
Pages : 133

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Book Description
Natural Convective Heat Transfer from Short Inclined Cylinders examines a heat transfer situation of significant, practical importance not adequately dealt with in existing textbooks or in any widely available review papers. Specifically, the book introduces the reader to recent studies of natural convection from short cylinders mounted on a flat insulated base where there is an “exposed” upper surface. The author considers the effects of the cylinder cross-sectional shape, the cylinder inclination angle, and the length-to-cross sectional size of the cylinder. Both numerical and experimental studies are discussed and correlation equations based on the results of these studies are reviewed. This book is ideal for professionals involved with thermal management and related systems, researchers, and graduate students in the field of natural convective heat transfer, instructors in graduate level courses in convective heat transfer.

Natural Convection from Circular Cylinders

Natural Convection from Circular Cylinders PDF Author: Sandra K. S. Boetcher
Publisher: Springer
ISBN: 3319081322
Category : Science
Languages : en
Pages : 57

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Book Description
This book presents a concise, yet thorough, reference for all heat transfer coefficient correlations and data for all types of cylinders: vertical, horizontal, and inclined. This book covers all natural convection heat transfer laws for vertical and inclined cylinders and is an excellent resource for engineers working in the area of heat transfer engineering.

Natural Convection Heat Transfer Between Arrays of Horizontal Cylinders and Their Enclosure

Natural Convection Heat Transfer Between Arrays of Horizontal Cylinders and Their Enclosure PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The natural convection heat transfer between arrays of horizontal, heated cylinders and their isothermal, cooled enclosure was experimentally investigated. Four different cylinder arrays were used: two in-line and two staggered. Four fluids (air, water, 20 cs silicone, and 96% glycerine) were used with Prandtl numbers ranging from 0.705 to 13090.0. There was no significant change in the Nusselt number between isothermal and constant heat flux conditions of the cylinder arrays. The average heat transfer coefficient was most affected by the spacing between cylinders and the total surface area of the cylinder arrays. The enclosure reduced the expected increase in both the average and the local heat transfer coefficients caused by changing the inner body from an in-line arrangement to a staggered arrangement of comparable spacing. An increase in fluid viscosity reduced the influence of the geometric effects.

Numerical and Experimental Studies of the Natural Convection Within a Horizontal Cylinder

Numerical and Experimental Studies of the Natural Convection Within a Horizontal Cylinder PDF Author: Roger Bell Stewart
Publisher:
ISBN:
Category : Cylinders
Languages : en
Pages : 72

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Experimental Investigation of Natural Convection from an Array of Uniformly Heated Horizontal Cylinders to Mercury

Experimental Investigation of Natural Convection from an Array of Uniformly Heated Horizontal Cylinders to Mercury PDF Author: Deing Wang
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 140

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Book Description
An experimental investigation was conducted to better understand the heat transfer process with natural convection from an array of uniformly heated horizontal cylinders to mercury. Five assembly geometries were studied, these being the single horizontal cylinder, two cylinders with spacing ratios S/D = 2,3 and 4, (S represents the center-to-center spacing between cylinders of diameter, D), and three cylinders with a single spacing ratio of S/D = 2. All cylinders were arranged in the same vertical plane. A scale analysis was employed to predict the relationship between the average Nusselt number and the Boussinesq number. In the case of the single cylinder good agreement was achieved between scale analysis and experimental results. The Nusselt number is a function of Boussinesq number only in the single cylinder case. These findings were extended to cases with two and three cylinders. Correlations of Nusselt number with different Boussinesq numbers, various ratios of spacing and diameters of cylinders have been established for these multiple cylinder cases.

Natural Convection Heat Transfer for a Staggered Array of Heated, Horizontal Cylinders Within a Rectangular Enclosure

Natural Convection Heat Transfer for a Staggered Array of Heated, Horizontal Cylinders Within a Rectangular Enclosure PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
This thesis presents the results of an experimental investigation of natural convection heat transfer in a staggered array of heated cylinders, oriented horizontally within a rectangular enclosure. The main purpose of this research was to extend the knowledge of heat transfer within enclosed bundles of spent nuclear fuel rods sealed within a shipping or storage container. This research extends Canaan's investigation of an aligned array of heated cylinders that thermally simulated a boiling water reactor (BWR) spent fuel assembly sealed within a shipping or storage cask. The results are presented in terms of piecewise Nusselt-Rayleigh number correlations of the form Nu = C(Ra)[sup n], where C and n are constants. Correlations are presented both for individual rods within the array and for the array as a whole. The correlations are based only on the convective component of the heat transfer. The radiative component was calculated with a finite-element code that used measured surface temperatures, rod array geometry, and measured surface emissivities as inputs. The correlation results are compared to Canaan's aligned array results and to other studies of natural convection in horizontal tube arrays.

Transient Natural Convection Heat Transfer in a Horizontal Cylinder

Transient Natural Convection Heat Transfer in a Horizontal Cylinder PDF Author: Howard G. Maahs
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 532

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NATURAL CONVECTION INSIDE A HORIZONTAL CYLINDER

NATURAL CONVECTION INSIDE A HORIZONTAL CYLINDER PDF Author: WILLIAM R. MARTINI
Publisher:
ISBN:
Category :
Languages : en
Pages : 200

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