Two-phase Flow and Pressure Drop in Flow Passages of Compact Heat Exchangers PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Two-phase Flow and Pressure Drop in Flow Passages of Compact Heat Exchangers PDF full book. Access full book title Two-phase Flow and Pressure Drop in Flow Passages of Compact Heat Exchangers by . Download full books in PDF and EPUB format.
Author: Publisher: ISBN: Category : Languages : en Pages : 31
Book Description
Two-phase flow experiments were performed with air/water mixtures in a small rectangular channel measuring 9.52 x 1.59 mm (aspects ratio equal to 6), for applications to compact heat exchangers. Pressure drop and flow pattern definition data were obtained over a large range of mass qualities (0.0002 to 1), and in the case of flow pattern data, a large range of mass fluxes (50 to 2,000 kg/m2s). A flow pattern map, based on visual observations and photographs of the flow patterns, is presented and compared with a map developed for a rectangular channel of the same aspect ratio but with dimensions twice those of the test channel, and with a map developed for a circular tube with the same hydraulic diameter of 3 mm. Pressure drop data are presented as a function of both mass quality and Martinelli parameter and are compared with state-of-the-art correlations and a modified Chisholm correlation. 13 refs.
Author: Publisher: ISBN: Category : Languages : en Pages : 31
Book Description
Two-phase flow experiments were performed with air/water mixtures in a small rectangular channel measuring 9.52 x 1.59 mm (aspects ratio equal to 6), for applications to compact heat exchangers. Pressure drop and flow pattern definition data were obtained over a large range of mass qualities (0.0002 to 1), and in the case of flow pattern data, a large range of mass fluxes (50 to 2,000 kg/m2s). A flow pattern map, based on visual observations and photographs of the flow patterns, is presented and compared with a map developed for a rectangular channel of the same aspect ratio but with dimensions twice those of the test channel, and with a map developed for a circular tube with the same hydraulic diameter of 3 mm. Pressure drop data are presented as a function of both mass quality and Martinelli parameter and are compared with state-of-the-art correlations and a modified Chisholm correlation. 13 refs.
Author: Publisher: ISBN: Category : Languages : en Pages : 31
Book Description
Two-phase flow experiments were performed with air/water mixtures in a small rectangular channel measuring 9.52 x 1.59 mm (aspects ratio equal to 6), for applications to compact heat exchangers. Pressure drop and flow pattern definition data were obtained over a large range of mass qualities (0.0002 to 1), and in the case of flow pattern data, a large range of mass fluxes (50 to 2,000 kg/m2s). A flow pattern map, based on visual observations and photographs of the flow patterns, is presented and compared with a map developed for a rectangular channel of the same aspect ratio but with dimensions twice those of the test channel, and with a map developed for a circular tube with the same hydraulic diameter of 3 mm. Pressure drop data are presented as a function of both mass quality and Martinelli parameter and are compared with state-of-the-art correlations and a modified Chisholm correlation. 13 refs.
Author: Sadik Kakaç Publisher: Springer Science & Business Media ISBN: 9400927908 Category : Technology & Engineering Languages : en Pages : 1090
Book Description
Two-phase flow heat exchangers are vital components of systems for power generation, chemical processing, and thermal environment control. The art and science of the design of such heat exchangers have advanced considerably in recent years. This is due to better understanding of the fundamentals of two-phase flow and heat transfer in simple geometries, greater appreciation of these processes in complex goemetries, and enhanced predictive capability through use of complex computer codes. The subject is clearly of great fundamental and practical importance. The NATO ASIan Thermal-Hydraulic Fundamentals and Design of Two-Phase Flow Heat Exchangers was held in Povoa de Varzim (near Porto), Portugal, July 6-17, 1987. participating in the organization of" the ASI were the Department of Mechanical Engineering and the Clean Energy Research Institute, University of Miami; Universidade do Porto; and the Department of Mechanical Engineering, Aeronautical Eng ineer ing, and Mechanics, Rensselaer Polytechnic Institute. The ASI was arranged primarily as a high-level teaching activity by experts representing both academic and industrial viewpoints. The program included the presentation of invited lectures, a limited number of related technical papers and discussion sessions.
Author: Sadik Kakaç Publisher: Springer Science & Business Media ISBN: 9400968485 Category : Science Languages : en Pages : 459
Book Description
Over the past two decades, two-phase flow and heat transfer problems associated with two-phase phenomena have been a challenge to many investigators. Two-phase flow applications are found in a wide range of engineering systems, such as nuclear and conventional power plants, evaporators of refrigeration systems and a wide vari ety of evaporative and condensive heat exchangers in the chemical industry. This publication is based on the invited lectures presented at the NATO Advanced Research Workshop on the Advances in Two-Phase Flow and Heat Transfer. The Horkshop was attended by more than 50 leading scientists and practicing engineers who work actively on two-phase flow and heat transfer research and applications in dif ferent sectors (academia, government, industry) of member countries of NATO. Some scientific leaders and experts on the subject matter from the non-NATO countries were also invited. They convened to discuss the state-of-the-art in two-phase flow and heat transfer and formulated recommendations for future research directions. To achieve these goals, invited key papers and a limited number of contributions were presented and discussed. The specific aspects of the subject were treated in depth in the panel sessions, and the unresolved problems identified. Suitable as a practical reference, these volumes incorporate a systematic approach to two-phase flow analysis.
Author: Sadik Kakaç Publisher: Springer Science & Business Media ISBN: 9400968450 Category : Science Languages : en Pages : 465
Book Description
Over the past two decades, two-phase flow and heat transfer problems associated with two-phase phenomena have been a challenge to many investigators. Two-phase flow applications are found in a wide range of engineering systems, such as nuclear and conventional power plants, evaporators of refrigeration systems and a wide vari ety of evaporative and condensive heat exchangers in the chemical industry. This publication is based on the invited lectures presented at the NATO Advanced Research Workshop on the Advances in Two-Phase Flow and Heat Transfer. The Horkshop was attended by more than 50 leading scientists and practicing engineers who work actively on two-phase flow and heat transfer research and applications in dif ferent sectors (academia, government, industry) of member countries of NATO. Some scientific leaders and experts on the subject matter from the non-NATO countries were also invited. They convened to discuss the state-of-the-art in two-phase flow and heat transfer and formulated recommendations for future research directions. To achieve these goals, invited key papers and a limited number of contributions were presented and discussed. The specific aspects of the subject were treated in depth in the panel sessions, and the unresolved problems identified. Suitable as a practical reference, these volumes incorporate a systematic approach to two-phase flow analysis.
Author: S. Mostafa Ghiaasiaan Publisher: Cambridge University Press ISBN: 1316785300 Category : Technology & Engineering Languages : en Pages : 1322
Book Description
Providing a comprehensive introduction to the fundamentals and applications of flow and heat transfer in conventional and miniature systems, this fully enhanced and updated edition covers all the topics essential for graduate courses on two-phase flow, boiling, and condensation. Beginning with a concise review of single-phase flow fundamentals and interfacial phenomena, detailed and clear discussion is provided on a range of topics, including two-phase hydrodynamics and flow regimes, mathematical modeling of gas-liquid two-phase flows, pool and flow boiling, flow and boiling in mini and microchannels, external and internal-flow condensation with and without noncondensables, condensation in small flow passages, and two-phase choked flow. Numerous solved examples and end-of-chapter problems that include many common design problems likely to be encountered by students, make this an essential text for graduate students. With up-to-date detail on the most recent research trends and practical applications, it is also an ideal reference for professionals and researchers in mechanical, nuclear, and chemical engineering.
Author: Afshin J. Ghajar Publisher: ISBN: 9783030872823 Category : Languages : en Pages : 0
Book Description
Part I of this book provides design engineers an elemental understanding of the variables that influence pressure drop and heat transfer in plain and micro-fin tubes to thermal systems using liquid single-phase flow in different industrial applications. The author and his colleagues were the first to determine experimentally the very important relationship between inlet geometry and transition. On the basis of their results, they developed practical and easy to use correlations for the isothermal and non-isothermal friction factor (pressure drop) and heat transfer coefficient (Nusselt number) in the transition region as well as the laminar and turbulent flow regions for different inlet configurations and fin geometry. The work presented in Part I of the book provides the thermal systems design engineer the necessary design tools. Part II of this book provides design engineers using gas-liquid two-phase flow in different industrial applications the necessary fundamental understanding of the two-phase flow variables. Two-phase flow literature reports a plethora of correlations for determination of flow patterns, void fraction, two- phase pressure drop and non-boiling heat transfer correlations. However, the validity of a majority of these correlations is restricted over a narrow range of two-phase flow conditions. Consequently, it is quite a challenging task for the end user to select an appropriate correlation/model for the type of two-phase flow under consideration. Selection of a correct correlation also requires some fundamental understanding of the two-phase flow physics and the underlying principles/assumptions/limitations associated with these correlations. Thus, it is of significant interest for a design engineer to have knowledge of the flow patterns and their transitions and their influence on two-phase flow variables. To address some of these issues and facilitate selection of appropriate two-phase flow models, Part II of this book presents a succinct review of the flow patterns, void fraction, pressure drop and non-boiling heat transfer phenomenon and recommend some of the well scrutinized modeling techniques. Reviews pressure drop, heat transfer coefficient, and inlet configuration effect in the transition region Includes void fraction correlations for flow patterns, pipe orientations, models for pressure drop calculations Presents non-boiling two-phase flow heat transfer correlations for different flow patterns and pipe orientations.
Author: Alexander Louis London Publisher: CRC Press ISBN: 9781560320128 Category : Heat exchangers Languages : en Pages : 798
Book Description
Heat exchangers are a crucial part of aerospace, marine, cryogenic and refrigeration technology. These essays cover such topics as complicated flow arrangements, complex extended surfaces, two-phase flow and irreversibility in heat exchangers, and single-phase heat transfer.
Author: Mahmoud Hamoda Publisher: ISBN: Category : Languages : en Pages :
Book Description
In compact heat exchangers, surface enhancements have been used for augmenting heat transfer due to the growing urgency for energy conservation and reduced environmental impact. Plates with corrugated walls are utilized in plate heat exchangers (PHEs) as they increase the effective heat transfer area, disrupt and reattach the boundary layer, and promote swirl flow resulting in a compact heat exchanger with high heat transfer performance. As a result, their applications have grown considerably to include a wide range of industries and processes, such as food, pharmaceutical, power generation, cooling engine oil, and dairy product processing. Due to heat exchanger size constraints, a compact heat exchanger's flow passages are often short in the automobile industry, especially for cooling engine oil and transmission oil. Hence, the heat exchanger is likely working with developing flow characteristics that have higher heat transfer and pressure drop compared to developed flow. A review of the open literature reveals a gap in the knowledge regarding the influence of the channel length on the thermal-hydraulic performance of PHE, which needs additional research. Also, no general models or correlations have been developed for predicting heat transfer and pressure drop in the entrance region of PHEs. Therefore, this thesis aims to experimentally investigate the effect of the channel length on the thermal-hydraulic performance of PHEs and to develop models for use in predicting pressure drop and heat transfer of PHEs, including the entrance region. An experimental facility is constructed to perform a series of single-phase flow tests on pressure drop and heat transfer of chevron PHE with two different channel lengths, 20.3 cm and 10.1 cm, and three different chevron angles, 30°,45°, and 60°. Mineral oil and water are used as the working fluids to cover laminar and turbulent flow regions. The results show that plates with a higher chevron angle experience higher pressure drop and heat transfer, which is consistent with the literature. Furthermore, the results of the effect of channel length on the Nusselt number of a PHE are very interesting as they demonstrate a significant impact of channel length on heat transfer performance of PHEs. The Nusselt number for short channels is considerably higher than for longer channels, indicating that thermal entrance effects are present. In addition, the Fanning friction factor results show that it is independent of the channel length at very low Reynolds numbers, while it is greatly impacted by the length of the channel at higher Reynolds numbers. The significance of these findings is that PHE channel length is an important factor that needs to be considered; however, it is often neglected due to assuming fully developed flow. This is important when designing a PHE and/or developing general models or correlations to predict the thermal and hydraulic performance of the PHE to cover a wide range of the Reynolds numbers. It is especially significant for applications where the length of the heat exchanger's flow passage is constrained. Finally, models for predicting the Fanning friction factor and Colburn factor are developed, which are a function of the plate length, corrugation depth, chevron angle, and Reynolds number. Agreement between the proposed models and the present experimental data is within ±20%. These models are also validated against numerical and experimental data from the literature and show good agreement within ±20% in most cases within the range of applicability. Thus, the proposed models may be used for preliminary designs of a chevron PHE.
Author: 
Author: 
Author: 
Author: Sadik Kakaç
Author: Sadik Kakaç
Author: Duncan Chisholm
Author: Sadik Kakaç
Author: S. Mostafa Ghiaasiaan
Author: Afshin J. Ghajar
Author: Alexander Louis London
Author: Mahmoud Hamoda