Author: Nat Vorayos
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 326
Book Description
The problem of simple mathematical models of laminar natural convective flow within a long vertical parallel-plate channels and circular tubes kept at uniformly heated walls is revisited to seek a clear physical understanding of heat transfer mechanisms. A series solution method to analyze the fully developed flow and an integral solution method to analyze the developing flow are used. Chapters 3, 4, and 5 of this dissertation constitute a series of three-paper manuscripts for submission to archival journals. The channels and circular tubes considered here are assumed to be sufficiently long to yield a fully developed flow thermally as well as hydrodynamically before the exit is encountered. In such fully developed flow situation, the fluid mass flow rate naturally induced into the channel due to buoyancy is found to be a function of the wall heating condition. The predicted average Nusselt number as a function of GrPrD/L not only agrees with the existing literature but also is found to be in a functional form comparable to that proposed by Elenbaas (1942 a and b). Our results show that, in spite of being driven by buoyancy (rather than by a pump or a blower), the flow and heat transfer characteristics in the fully developed regime are essentially the same as those of fully developed laminar forced convection in which the flow is externally driven. This observation is confirmed to be valid also in the study (Chapter 5) of laminar natural convection in the developing (entrance) region within a long vertical parallel-plate channel and circular tube. The mass flow rate, which has to remain invariant with axial location even in the entry region, is determined by the flow in the fully developed region. This is the same mechanism involved in forced convection in which the fluid outside the developing boundary layers (i.e. the core flow) is forced to accelerate in the entrance region. The entrance length of channel natural convection is also discovered to be about the same as that in forced convection.
Laminar Natural Convection Within Long Vertical Uniformly Heated Parallel-plate Channels and Circular Tubes
Author: Nat Vorayos
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 326
Book Description
The problem of simple mathematical models of laminar natural convective flow within a long vertical parallel-plate channels and circular tubes kept at uniformly heated walls is revisited to seek a clear physical understanding of heat transfer mechanisms. A series solution method to analyze the fully developed flow and an integral solution method to analyze the developing flow are used. Chapters 3, 4, and 5 of this dissertation constitute a series of three-paper manuscripts for submission to archival journals. The channels and circular tubes considered here are assumed to be sufficiently long to yield a fully developed flow thermally as well as hydrodynamically before the exit is encountered. In such fully developed flow situation, the fluid mass flow rate naturally induced into the channel due to buoyancy is found to be a function of the wall heating condition. The predicted average Nusselt number as a function of GrPrD/L not only agrees with the existing literature but also is found to be in a functional form comparable to that proposed by Elenbaas (1942 a and b). Our results show that, in spite of being driven by buoyancy (rather than by a pump or a blower), the flow and heat transfer characteristics in the fully developed regime are essentially the same as those of fully developed laminar forced convection in which the flow is externally driven. This observation is confirmed to be valid also in the study (Chapter 5) of laminar natural convection in the developing (entrance) region within a long vertical parallel-plate channel and circular tube. The mass flow rate, which has to remain invariant with axial location even in the entry region, is determined by the flow in the fully developed region. This is the same mechanism involved in forced convection in which the fluid outside the developing boundary layers (i.e. the core flow) is forced to accelerate in the entrance region. The entrance length of channel natural convection is also discovered to be about the same as that in forced convection.
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 326
Book Description
The problem of simple mathematical models of laminar natural convective flow within a long vertical parallel-plate channels and circular tubes kept at uniformly heated walls is revisited to seek a clear physical understanding of heat transfer mechanisms. A series solution method to analyze the fully developed flow and an integral solution method to analyze the developing flow are used. Chapters 3, 4, and 5 of this dissertation constitute a series of three-paper manuscripts for submission to archival journals. The channels and circular tubes considered here are assumed to be sufficiently long to yield a fully developed flow thermally as well as hydrodynamically before the exit is encountered. In such fully developed flow situation, the fluid mass flow rate naturally induced into the channel due to buoyancy is found to be a function of the wall heating condition. The predicted average Nusselt number as a function of GrPrD/L not only agrees with the existing literature but also is found to be in a functional form comparable to that proposed by Elenbaas (1942 a and b). Our results show that, in spite of being driven by buoyancy (rather than by a pump or a blower), the flow and heat transfer characteristics in the fully developed regime are essentially the same as those of fully developed laminar forced convection in which the flow is externally driven. This observation is confirmed to be valid also in the study (Chapter 5) of laminar natural convection in the developing (entrance) region within a long vertical parallel-plate channel and circular tube. The mass flow rate, which has to remain invariant with axial location even in the entry region, is determined by the flow in the fully developed region. This is the same mechanism involved in forced convection in which the fluid outside the developing boundary layers (i.e. the core flow) is forced to accelerate in the entrance region. The entrance length of channel natural convection is also discovered to be about the same as that in forced convection.
Fully Developed Laminar Natural Convection in a Vertical Parallel Plate Channel with Symmetric Uniform Wall Temperature
Author: Robert H. Willie
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 72
Book Description
Described in this thesis is an investigation of the fully developed natural convection heat transfer in a vertical channel formed by two infinitely wide parallel plates maintained at a uniform wall temperature. Closed-form solutions for the velocity and temperature profiles are developed along with local and averaged Nusselt numbers. The local Nusselt number based on bulk temperature is found to be 3.77. This result is an analog corresponding to 7.60 for fully developed laminar forced convection in a parallel plate channel with uniform wall temperature boundary condition. The local Nusselt number based on the ambient temperature is deduced as a function of flowwise location. Results are compared with existing numerical and experimental data to find good agreement.
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 72
Book Description
Described in this thesis is an investigation of the fully developed natural convection heat transfer in a vertical channel formed by two infinitely wide parallel plates maintained at a uniform wall temperature. Closed-form solutions for the velocity and temperature profiles are developed along with local and averaged Nusselt numbers. The local Nusselt number based on bulk temperature is found to be 3.77. This result is an analog corresponding to 7.60 for fully developed laminar forced convection in a parallel plate channel with uniform wall temperature boundary condition. The local Nusselt number based on the ambient temperature is deduced as a function of flowwise location. Results are compared with existing numerical and experimental data to find good agreement.
Fully Developed Laminar Natural Convection in a Vertical Parallel-plate Duct with Constant Wall Heat Flux
Author: Gülçin Aktan
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 68
Book Description
The problem of heat transfer due to free convection in a channel formed by two parallel, isoflux, vertical plates is of considerable importance in electronic cooling applications, thermosiphons, the optimum spacing of plates or components, industrial stacks, heat exchangers, nuclear power plants and combustion involving vertical walls. Although in each implementation other physical considerations are necessary, fully developed flow with symmetric isoflux boundary condition offers a fundamental heat transfer problem. Thus, here, the fully developed laminar natural convective flow of a viscous fluid in a channel formed by heated infinitely long vertical plates is investigated. Using boundary layer approximations, the basic governing equations of continuity, momentum and energy are combined into a single equation and solved analytically for a symmetric uniform heat flux boundary condition to find the velocity and temperature profiles and heat transfer coefficients for the flow. The closed-form solutions that are presented are strightforward and simple compared to previous solutions existing in the literature. For Rayleigh numbers sufficiently small to ensure a fully developed flow, it is found that the local Nusselt number based on local wall to bulk temperature difference is 4.118. Furthermore the pressure and mass flow rates for this particular geometry are also investigated.
Publisher:
ISBN:
Category : Heat
Languages : en
Pages : 68
Book Description
The problem of heat transfer due to free convection in a channel formed by two parallel, isoflux, vertical plates is of considerable importance in electronic cooling applications, thermosiphons, the optimum spacing of plates or components, industrial stacks, heat exchangers, nuclear power plants and combustion involving vertical walls. Although in each implementation other physical considerations are necessary, fully developed flow with symmetric isoflux boundary condition offers a fundamental heat transfer problem. Thus, here, the fully developed laminar natural convective flow of a viscous fluid in a channel formed by heated infinitely long vertical plates is investigated. Using boundary layer approximations, the basic governing equations of continuity, momentum and energy are combined into a single equation and solved analytically for a symmetric uniform heat flux boundary condition to find the velocity and temperature profiles and heat transfer coefficients for the flow. The closed-form solutions that are presented are strightforward and simple compared to previous solutions existing in the literature. For Rayleigh numbers sufficiently small to ensure a fully developed flow, it is found that the local Nusselt number based on local wall to bulk temperature difference is 4.118. Furthermore the pressure and mass flow rates for this particular geometry are also investigated.
An Analysis of Natural Convection Between Finite Vertical Parallel Plates
Author: James Quintiere
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 356
Book Description
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 356
Book Description
Experimental Study of Combined Forced and Free-laminar Convection in a Vertical Tube
Author: Theodore M. Hallman
Publisher:
ISBN:
Category : Fluid mechanics
Languages : en
Pages : 52
Book Description
Publisher:
ISBN:
Category : Fluid mechanics
Languages : en
Pages : 52
Book Description
Combined Forced and Free Turbulent Convection in a Vertical Tube
Author: M. S. Ojalvo
Publisher:
ISBN:
Category : Fluids
Languages : en
Pages : 56
Book Description
An analytical study was made of turbulent heat transfer in a vertical circular tube under the conditions of combined forced and free convection with uniform heat flux at the wall.
Publisher:
ISBN:
Category : Fluids
Languages : en
Pages : 56
Book Description
An analytical study was made of turbulent heat transfer in a vertical circular tube under the conditions of combined forced and free convection with uniform heat flux at the wall.
Free Convection in Fluids Having a Volume Heat Source
Author:
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 44
Book Description
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 44
Book Description
Natural Convection from Open- and Closed-sided Vertical Parallel Plates and from Fin-tube Configurations
Author: Parviz Ahmadi Bahrami
Publisher:
ISBN:
Category :
Languages : en
Pages : 214
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 214
Book Description
Recent Advances in Materials, Mechanics and Management
Author: Sheela Evangeline
Publisher: CRC Press
ISBN: 135122753X
Category : Technology & Engineering
Languages : en
Pages : 512
Book Description
These proceedings present a selection of papers presented at the 3rd International Conference on Materials Mechanics and Management 2017 (IMMM 2017), which was jointly organized by the Departments of Civil Engineering, Mechanical Engineering and Architecture of College of Engineering Trivandrum. Developments in the fields of materials, mechanics and management have paved the way for overall improvements in all aspects of human life. The quest for meeting the requirements of the rapidly increasing population has led to revolutionary construction and production technologies aiming at optimum management and use of natural resources. The objective of this conference was to bring together experts from academic institutions, industries, research organizations and professionals for sharing of knowledge, expertise and experience in the emerging trends related to Civil Engineering, Mechanical Engineering and Architecture. IMMM 2017 provided opportunities for young researchers to actively engage in research discussions, new research interests, research ethics and professional development.
Publisher: CRC Press
ISBN: 135122753X
Category : Technology & Engineering
Languages : en
Pages : 512
Book Description
These proceedings present a selection of papers presented at the 3rd International Conference on Materials Mechanics and Management 2017 (IMMM 2017), which was jointly organized by the Departments of Civil Engineering, Mechanical Engineering and Architecture of College of Engineering Trivandrum. Developments in the fields of materials, mechanics and management have paved the way for overall improvements in all aspects of human life. The quest for meeting the requirements of the rapidly increasing population has led to revolutionary construction and production technologies aiming at optimum management and use of natural resources. The objective of this conference was to bring together experts from academic institutions, industries, research organizations and professionals for sharing of knowledge, expertise and experience in the emerging trends related to Civil Engineering, Mechanical Engineering and Architecture. IMMM 2017 provided opportunities for young researchers to actively engage in research discussions, new research interests, research ethics and professional development.
Advanced Heat and Mass Transfer
Author: Amir Faghri
Publisher: Global Digital Press
ISBN: 0984276009
Category : Heat
Languages : en
Pages : 958
Book Description
All relevant advanced heat and mass transfer topics in heat conduction, convection, radiation, and multi-phase transport phenomena, are covered in a single textbook, and are explained from a fundamental point of view.
Publisher: Global Digital Press
ISBN: 0984276009
Category : Heat
Languages : en
Pages : 958
Book Description
All relevant advanced heat and mass transfer topics in heat conduction, convection, radiation, and multi-phase transport phenomena, are covered in a single textbook, and are explained from a fundamental point of view.