Author: Thamir R. Al-Alusi
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 448
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.
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
Author: Thamir R. Al-Alusi
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 448
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.
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 448
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.
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 486
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 486
Book Description
Journal of Heat Transfer
Author:
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 568
Book Description
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 568
Book Description
American Doctoral Dissertations
Author:
Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 760
Book Description
Publisher:
ISBN:
Category : Dissertation abstracts
Languages : en
Pages : 760
Book Description
Applied Mechanics Reviews
Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 384
Book Description
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 384
Book Description
Circular
Author:
Publisher:
ISBN:
Category : Engineering
Languages : en
Pages : 272
Book Description
Publisher:
ISBN:
Category : Engineering
Languages : en
Pages : 272
Book Description
Dissertation Abstracts International
Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 802
Book Description
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 802
Book Description
Research Activities Annual Report
Author:
Publisher:
ISBN:
Category : Engineering
Languages : en
Pages : 256
Book Description
Publisher:
ISBN:
Category : Engineering
Languages : en
Pages : 256
Book Description
Numerical and Experimental Studies of the Natural Convection Within a Horizontal Cylinder
Author: Roger Bell Stewart
Publisher:
ISBN:
Category : Cylinders
Languages : en
Pages : 72
Book Description
Publisher:
ISBN:
Category : Cylinders
Languages : en
Pages : 72
Book Description
Natural Convection Heat Transfer for a Staggered Array of Heated, Horizontal Cylinders Within a Rectangular Enclosure
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
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.
Publisher:
ISBN:
Category :
Languages : en
Pages :
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.