Download or read book Heat Transfer and Pressure Drop of Developing Flow in Smooth Tubes in the Transitional Flow Regime written by Marilize Everts and published by . This book was released on 2014 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat exchangers have a wide range of applications and engineers need accurate correlations to optimise the design of these heat exchangers. During the design process, the best compromise between high heat transfer coefficients and relatively low pressure drops is usually in the transitional flow regime. Limited research has been done on tube flow in the transitional flow regime. These studies considered either fully developed flow, or average measurements of developing flow across a tube length. No research has been done with the focus on developing flow in smooth tubes in the transitional flow regime. Therefore, the purpose of this study was to experimentally investigate the heat transfer and pressure drop characteristics of developing flow in the transitional flow regime. An experimental set-up was designed, built and validated against literature. Heat transfer and pressure drop measurements were taken at Reynolds numbers between 500 and 10 000 at three different heat fluxes (6.5, 8.0 and 9.5 kW/m2). A total of 398 mass flow rate measurements, 19 158 temperature measurements and 370 pressure drop measurements were taken. Water was used as the test fluid and the Prandtl number ranged between 3 and 7. The test section was a smooth circular tube and had an inner diameter and length of 11.52 mm and 2.03 m, respectively. An uncertainty analysis showed that the uncertainties of the Nusselt numbers and Colburn j-factors varied between 4% and 5% while the friction factor uncertainties varied between 1% and 17%. Five different flow regimes (laminar, developing laminar, transitional, low-Reynolds-number-end and turbulent) were identified in the first part of the tube during the experiments and nomenclature was developed to more clearly identify the boundaries of the different flow regimes. The developing laminar regime was unique to developing flow and decreased along the tube length. Both the start and end of transition were delayed along the tube length and the width of the transition region decreased slightly. This is in contrast with the results obtained in literature where the effect of the non-dimensional distance from the inlet on fully developed flow in the transition region was investigated. Transition was also slightly delayed with increasing heat flux, but secondary flow effects had no significant influence on the width of the transition region. The relationship between heat transfer and pressure drop was investigated and correlations were developed to predict the Nusselt number as a function of friction factor, Reynolds number and Prandtl number in the laminar, transitional, low-Reynolds-number-end and turbulent flow regimes. Overall, it can be concluded that the heat transfer characteristics of developing and fully developed flow differ significantly and more work needs to be done to fully understand the fundamentals before the heat transfer and pressure drop characteristics are fully understood.

Download or read book Fully Developed Forced Convection Heat Transfer and Pressure Drop in a Smooth Tube in the Transitional Flow Regime written by Nicola Mary Van der Merwe and published by . This book was released on 2017 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extensive work has been done on characterising convective heat transfer and pressure drop in smooth tubes in the laminar and turbulent flow regimes. However, little work was completed in the transitional flow regime. In all previous transitional studies, experiments that were conducted between the laminar and turbulent flow regimes were with mixed convection in the laminar flow regime and not in the forced convection flow regime. The secondary flow that occurs during mixed convection should most probably influence the characteristics in the transitional flow regime. It can therefore be expected that the transitional flow characteristics of forced convection and mixed convection will be different. However, the transitional characteristics of forced convection flow have not yet been determined. The purpose of this study was therefore to determine the heat transfer and pressure drop transitional characteristics specifically in the forced convection flow regime. Furthermore, to focus on determining these factors for a circular, horizontal smooth tube for fully developed flow. The characteristics were determined in an experimental set-up through which flow occurred through a test section consisting of a horizontal and circular smooth tube. The test-section inside diameter was 4.04 mm, and the tube length was 8.4 m. Water was used as the test fluid and was circulated through the test section which was heated at a constant heat flux. A calming section with a square edge inlet was upstream of the test section. Temperatures at the tube inlet, outlet and outer surface of the test section were measured with a total of 58 thermocouples. Two pressure taps was also installed on the test section and was connected to a pressure transducer for pressure drop measurements. Experiments were conducted mainly on the last part of the test section where fully developed flow occurred. Experiments were conducted between Reynolds numbers of 1 000 to 10 000, Prandtl numbers of 3 to 8, and Rayleigh numbers of 330 and 11 000 (heat fluxes of 0.89 kW/m2 to 3.26 kW/m2). It was found that the heat transfer transitional range coincided with the friction factor transition range with a Reynolds number range of 2 484 to 2 849. Forced convection results in the laminar regime was achieved and compared well to literature. The results were mapped on published flow regime maps. This was inconclusive as the published flow regime maps have been specifically developed for fixed parameters that did not match the parameters of this study..

Download or read book Single phase Mixed Convection of Developing and Fully Developed Flow in Smooth Horizontal Tubes in the Laminar Transitional Quasi turbulent and Turbulent Flow Regimes written by Marilize Everts and published by . This book was released on 2017 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: The laminar and turbulent flow regimes have been extensively investigated from as early as 1883, and research has been devoted to the transitional flow regime since the 1990s. However, there are several gaps in the mixed convection literature, especially when the flow is still developing. The purpose of the study was to experimentally investigate the heat transfer and pressure drop characteristics of developing and fully developed flow of low Prandtl number fluids in smooth horizontal tubes for forced and mixed convection conditions. An experimental set-up was designed and built, and results were validated against literature. Two smooth circular test sections with inner diameters of 4 mm and 11.5 mm were used, and the maximum length-to-diameter ratios were 1 373 and 872 respectively. Heat transfer measurements were taken at Reynolds numbers between 500 and 10 000 at different constant heat fluxes. A total of 648 mass flow rate measurements, 70 301 temperature measurements and 2 536 pressure drop measurements were taken. Water was used as the test fluid and the Prandtl number ranged between 3 and 7. It was found that a longer thermal entrance length was required for simultaneously hydrodynamically and thermally developing flow. Therefore, a coefficient of at least 0.12 (and not 0.05 as advised in most literature) was suggested. Because free convection effects decreased the thermal entrance length, correlations were also developed to calculate the thermal entrance length for mixed convection conditions. The boundaries between the flow regimes were defined mathematically, and terminology to define transitional flow characteristics was presented. For laminar flow, three different regions (forced convection developing, mixed convection developing and fully developed) were identified in the local heat transfer results and nomenclature and correlations were developed to define and quantify the boundaries of these regions. Correlations were also developed to calculate the local and average laminar Nusselt numbers of mixed convection developing flow. The laminar-turbulent transition along the tube length occurred faster with increasing Reynolds number, and was also influenced by free convection effects. As free convection effects became significant, the effect was first to disrupt the fluctuations inside the test section, leading to a slower laminar-turbulent transition along the tube length compared with forced convection conditions. However, as free convection effects were increased, the fluctuations inside the test section increased and caused the laminar-turbulent transition along the tube length to occur faster. The Reynolds number at which transition started was found to be independent of axial position for both developing and fully developed flow. However, the end of transition occurred earlier as the flow approached fully developed flow. When the flow was fully developed, the end of transition became independent of axial position. Furthermore, free convection effects affected both the start and end of the transitional flow regime, and caused the Reynolds number range of the transitional flow regime to decrease. Correlations were therefore developed to determine the start and end of the transitional flow regime for developing and fully developed flow in mixed convection conditions. The transitional flow regime across the tube length was divided into three regions. In the first region, the width of the transitional flow regime decreased significantly with axial position as the thermal boundary layer thickness increased, and free convection effects were negligible. In Region 2, the width of the transitional flow regime decreased with axial position, due to the development of the thermal boundary layer, as well as with increasing free convection effects. In the fully developed region (Region 3), the width of the transitional flow regime was independent of axial position, but decreased significantly with increasing free convection effects. At high Grashof numbers, free convection effects even caused the transitional flow regime of fully developed flow to become negligible. It was found that the boundaries of the different flow regimes were the same for pressure drop and heat transfer, and a relationship between pressure drop and heat transfer existed in all four flow regimes. In the laminar flow regime, this relationship was a function of Grashof number (thus free convection effects), while it was a function of Reynolds number in the other three flow regimes. Correlations to predict the average Nusselt numbers, as well as the friction factors as a function of average Nusselt number, for developing and fully developed flow in all flow regimes were developed. Finally, flow regime maps were developed to predict the convection flow regime for developing and fully developed flow for a wide range of tube diameters and Prandtl numbers, and these flow regime maps were unique for four reasons. Firstly, they contained contour lines that showed the Nusselt number enhancements due to the free convection effects. Secondly, they were valid for a wide range of tube diameters and Prandtl numbers. Thirdly, the flow regime maps were developed as a function of temperature difference (Grashof number) and heat flux (modified Grashof number). Finally, four of the six flow regime maps were not only valid for fully developed flow, but also for developing flow.

Download or read book Advances in Heat Transfer written by and published by Academic Press. This book was released on 2019-10-24 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Heat Transfer, Volume 51, provides in-depth review articles from a broader scope than in traditional journals or texts, with this comprehensive release covering chapters on Micro and nanoparticle transport phenomena in confined flows, A review of heat transfer in the transitional flow regime, and much more. - Fills the information gap between regularly scheduled journals and university-level textbooks by providing in-depth review articles over a broader scope than in traditional journals or texts - Provides essential reading for all mechanical, chemical and industrial engineers working in the field of heat transfer - Presents a great resource for use in graduate school level courses

Download or read book Single phase Heat Transfer and Pressure Drop of Water Cooled at a Constant Wall Temperature Inside Horizontal Circular Smooth and Enhanced Tubes with Different Inlet Configuration in the Transitional Flow Regime written by Jonathan Albert Olivier and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It is common practice to design water chiller units and heat exchangers in such a way that they do not operate within the transition region. This is mainly due to the perceived chaotic behaviour as well as the paucity of information in this region. Due to design constraints or change of operating conditions, however, exchangers are often forced to operate in this region. This is even worse for enhanced tubes as much less information within this region is available. It is also well known that the entrance has an influence on where transition occurs, adding to the woes of available information. The purpose of this study is thus to obtain heat transfer and friction factor data in the transition region of fully developed and developing flows inside smooth and enhanced tubes, using water as the working fluid, and to develop correlations from these results. The use of different inlets, tube diameters and enhanced tubes was also investigated with regards to the commencement of transition. Heat transfer and pressure drop data were obtained from six different types of tubes with diameters of 15.88 mm (5/8??) and 19.02 mm (3/4??). Low fin enhanced tubes with a fin height to diameter ratio of 0.4 and helix angles of 18 and 27 were investigated. Heat transfer was obtained by means of an in-tube heat exchanger with the cooling of water being used as the test fluid. Reynolds numbers ranged between 1 000 and 20 000 while Prandtl numbers were in the order of 4 to 6. Uncertainties in heat transfer coefficient and friction factors were on average below 2.5% and 10% respectively. Adiabatic friction factor results showed that the use of different inlets influenced the commencement of transition. The smoother the inlet profile the more transition was delayed, confirming previous work done. The effect of increasing tube diameters had a slight delay in transition. Enhanced tubes caused transition to occur at lower Reynolds numbers which was accounted for by the fin height and not the helix angle. Heat transfer results showed that transition occurred at approximately the same Reynolds number for all the different inlets and enhanced tubes. This was attributed to the secondary flow forces influencing the growing hydrodynamic boundary layer. These secondary flow forces also influenced the laminar heat transfer and diabatic friction factors with both these parameters being higher. Turbulent enhanced tube heat transfer results were higher than those of the smooth tube, with the tube with the greatest helix angle showing the greatest increase. Correlations were developed for all the tubes and their inlets and predicted all the data on average to within 3%.

Download or read book Fluid Mechanics and Fluid Power Vol 3 written by Suvanjan Bhattacharyya and published by Springer Nature. This book was released on 2023-04-17 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the select proceedings of the 48th National Conference on Fluid Mechanics and Fluid Power (FMFP 2021) held at BITS Pilani in December 2021. It covers the topics such as fluid mechanics, measurement techniques in fluid flows, computational fluid dynamics, instability, transition and turbulence, fluid‐structure interaction, multiphase flows, micro- and nanoscale transport, bio-fluid mechanics, aerodynamics, turbomachinery, propulsion and power. The book will be useful for researchers and professionals interested in the broad field of mechanics.

Download or read book Heat Transfer and Pressure Drop Characteristics of Smooth Tubes at a Constant Heat Flux in the Transitional Flow Regime written by and published by . This book was released on 2011 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Art of Measuring in the Thermal Sciences written by Josua Meyer and published by CRC Press. This book was released on 2020-11-05 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Art of Measuring in the Thermal Sciences provides an original state-of-the-art guide to scholars who are conducting thermal experiments in both academia and industry. Applications include energy generation, transport, manufacturing, mining, processes, HVAC&R, etc. This book presents original insights into advanced measurement techniques and systems, explores the fundamentals, and focuses on the analysis and design of thermal systems. Discusses the advanced measurement techniques now used in thermal systems Links measurement techniques to concepts in thermal science and engineering Draws upon the original work of current researchers and experts in thermal-fluid measurement Includes coverage of new technologies, such as micro-level heat transfer measurements Covers the main types of instrumentation and software used in thermal-fluid measurements This book offers engineers, researchers, and graduate students an overview of the best practices for conducting sound measurements in the thermal sciences.

Download or read book Introduction to Convective Heat Transfer written by Nevzat Onur and published by John Wiley & Sons. This book was released on 2023-04-18 with total page 805 pages. Available in PDF, EPUB and Kindle. Book excerpt: INTRODUCTION TO CONVECTIVE HEAT TRANSFER A highly practical intro to solving real-world convective heat transfer problems with MATLAB® and MAPLE In Introduction to Convective Heat Transfer, accomplished professor and mechanical engineer Nevzat Onur delivers an insightful exploration of the physical mechanisms of convective heat transfer and an accessible treatment of how to build mathematical models of these physical processes. Providing a new perspective on convective heat transfer, the book is comprised of twelve chapters, all of which contain numerous practical examples. The book emphasizes foundational concepts and is integrated with explanations of computational programs like MATLAB® and MAPLE to offer students a practical outlet for the concepts discussed within. The focus throughout is on practical, physical analysis rather than mathematical detail, which helps students learn to use the provided computational tools quickly and accurately. In addition to a solutions manual for instructors and the aforementioned MAPLE and MATLAB® files, Introduction to Convective Heat Transfer includes: A thorough introduction to the foundations of convective heat transfer, including coordinate systems, and continuum and thermodynamic equilibrium concepts Practical explorations of the fundamental equations of laminar convective heat transfer, including integral formulation and differential formulation Comprehensive discussions of the equations of incompressible external laminar boundary layers, including laminar flow forced convection and the thermal boundary layer concept In-depth examinations of dimensional analysis, including the dimensions of physical quantities, dimensional homogeneity, and dimensionless numbers Ideal for first-year graduates in mechanical, aerospace, and chemical engineering, Introduction to Convective Heat Transfer is also an indispensable resource for practicing engineers in academia and industry in the mechanical, aerospace, and chemical engineering fields.

Download or read book Nanofluid Applications for Advanced Thermal Solutions written by Shriram S. Sonawane and published by Elsevier. This book was released on 2023-06-28 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanofluid Applications for Advanced Thermal Solutions covers heat transfer applications of nanofluids in a variety of fields and the main techniques used in nanofluid flow and heat transfer analysis. The book features an introduction to heat transfer, nanofluid conduction, convection and nanofluid boiling and provides a thorough understanding of a variety of applications, including the energy storage component of solar PVT systems. It covers fundamental topics such as the analysis and measurement of thermophysical properties, convection, and heat transfer equipment performance, and provides a rigorous framework to assist readers in developing new nanofluid-based devices. Finally, the book explores convective instabilities, nanofluids in porous media, and entropy generation in nanofluids. This will be a valuable resource for upper undergraduate, postgraduate, and doctoral students and researchers in the fields of nanotechnology and nanofluids looking at heat transfer processes in chemical engineering and the petroleum industry. - Provides a comprehensive overview of the heat transfer application of nanofluids in a variety of fields - Features numerical and experimental investigations of hybrid and mono nanoparticles based nanofluids - Explores comparative performance investigations of various nanofluids for absorption/regeneration and metal extraction/stripping operations - Provides case examples of operation and scale-up challenges for nanofluid applications in the industrial process

Download or read book Laminar Flow Forced Convection in Ducts written by R. K. Shah and published by Academic Press. This book was released on 2014-06-28 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laminar Flow Forced Convection in Ducts is a sourcebook for compact heat exchanger analytical data. This book describes the analytical solutions for laminar fluid flow and forced convection heat transfer in circular and noncircular pipes, including applicable differential equations and boundary conditions involving velocity and temperature problems of fluid flow. The book also discusses fluid flow—how much power is required to pump fluids through the heat exchanger, as well as the heat transfer—the determination of q" distribution, and the temperature of fluid and walls. The text also analyzes the coolant or heat transfer fluid flows in a nuclear power reactor composed of a bundle of circular section fuel rods located inside a round tube. R.A. Axford addresses fluid flow and heat transfers results for the rod bundle geometry in "Heat Transfer in Rod Bundles." The book also provides an overview and guidelines that can be used for the designer and the applied mathematician. This book is suitable for engineers working in electronics, aerospace, instrumentation, and biomechanics that use cooling or heating exchanges or solar collection systems.

Download or read book Handbook of Single Phase Convective Heat Transfer written by Sadik Kakaç and published by Wiley-Interscience. This book was released on 1987-11-03 with total page 1268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Very Good,No Highlights or Markup,all pages are intact.

Download or read book Single phase Forced and Mixed Convection in the Laminar and Transitional Flow Regimes of Inclined Smooth Tubes with Inlet Disturbances written by Abubakar Idris Bashir and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Laminar and transitional flow regimes in tubes have been extensively investigated in the literature. However, there are several gaps in the forced and mixed convection literature, especially for inclined tubes with different inlet disturbances. The purpose of this study was to experimentally investigate the effect of tube inclination and inlet contraction ratio on the single-phase heat transfer and pressure drop characteristics in the laminar and transitional flow regimes for pure forced and mixed convection conditions. An experimental set-up was designed, constructed and validated against literature with the test section in a horizontal and different vertical orientation. The test section was 4.6 m long and was made from a smooth hard drawn copper tube with measured inner and outer diameters of 5.1 mm and 6.3 mm, respectively. Experiments were conducted at various inclination angles from vertical upward flow (+90AÌ2℗ð) to vertical downward flow (aÌ22́Ơ0́−90AÌ2℗ð), with horizontal flow (0AÌ2℗ð) and several other angles in between. A total of 2 679 mass flow rate measurements, 174 135 temperature measurements and 2 679 pressure drop measurements were conducted using water (Prandtl numbers between 3.5 and 8.1) as working fluid. The Reynolds number range covered were from 400 to 6 000 at constant heat fluxes varying from 1 to 8 kW/m2. Four different types of inlets namely; square-edged and re-entrant inlet with different inlet contraction ratios (5, 11, 14 and 33), as well as hydrodynamically fully developed and 90AÌ2℗ð bend inlets were used. It was found that an increase in the inclination angle from horizontal flow (0AÌ2℗ð) to vertical (AÌ2℗ł90AÌ2℗ð) flow, decreased the buoyancy effects which led to decreased laminar heat transfer coefficients and friction factors for both upward and downward flows. The onset of buoyancy effects was significant near the vertical inclination angles and caused a rapid increase in the laminar heat transfer coefficients and friction factors when the inclination angles moved from vertical to horizontal orientations. An inclined tube Grashof number which is a function of inclination angle was defined and used to express the laminar Nusselt numbers as a forced convection part plus an enhancement component owing to mixed convection. The laminar friction factors were expressed as a function of a forced convection/isothermal part multiplied by the mixed convection part. Furthermore, it was found that the critical Reynolds numbers at which transitional flow regime started increased as the inclination angles increased from horizontal to vertical, while the end of transitional flow regime were inclination angle independent. This caused the width of the transitional flow regime to decrease, as well as the transition gradients to increase, with increasing inclination angles at different heat fluxes. It was also found that the flow directions (upward and downward) had a negligible effect on the heat transfer coefficients and friction factors in the entire transition and quasi-turbulent regions. The fully developed laminar forced convection Nusselt numbers were not constant at 4.36, but were a function of Reynolds number for Reynolds numbers higher than 1 000. Therefore, a revised laminar Nusselt number correlation for smooth circular tubes was developed. The fully developed laminar forced convection friction factors were, as expected, equal to 64/Re. For both the forced convection heat transfer and pressure drop characteristics, transition occurred at the same mass flow rates for all the heat fluxes, including isothermal flow, but the critical Reynolds numbers increased with an increase in heat flux. For forced convection condition, the width of the transitional flow regime in the fully developed region remained constant for all heat fluxes. For a square-edged inlet geometry, the transition from the laminar to the turbulent flow regimes occurred earlier as the inlet contraction ratio increased, while for the re-entrant inlet, transition was delayed. The transitional flow regime was significantly affected by smaller contraction ratios and this effect increased with increasing heat flux. However, it was found that the critical Reynolds numbers were independent of inlet geometry for contraction ratios larger than 33. For the 90AÌ2℗ð bend inlet, transition occurred earlier than all the other inlet geometries and contraction ratios.

Download or read book Single and Two Phase Flow Pressure Drop and Heat Transfer in Tubes written by Afshin J. Ghajar and published by Springer Nature. This book was released on 2022-01-11 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 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. It also provides design engineers using gas-liquid, two-phase flow in different industrial applications the necessary fundamentals of the two-phase flow variables. 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. This work presented herein provides the thermal systems design engineer the necessary design tools. The author further presents a succinct review of the flow patterns, void fraction, pressure drop and non-boiling heat transfer phenomenon and recommends some of the well scrutinized modeling techniques.

Download or read book The Influence of a Multiple Tube Inlet Condition on Heat Transfer in the Transitional Flow Regime written by Leslie Matthew James Pallent and published by . This book was released on 2017 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the industrial design of heat exchangers, engineers have long followed the general rule of avoiding transitional flow, and have rather designed a system operating in the turbulent flow regime. Whilst the turbulent regime is better for heat transfer, the higher friction inside the tube results in a much higher pressure drop which inevitably results in the system requiring a more powerful pump than if the system were to operate in the laminar regime. Designing a heat exchanger that operates in the turbulent flow regime is often the safer option, since little published design data is available for flow in the transitional flow regime, giving rise to numerous unwanted uncertainties during the design phase. Recent research into the transitional flow regime has resulted in promising experimental data that shows the regime is not as unstable as previously suspected. The regime allows for higher heat transfer than flows in the laminar regime, yet lower pressure drops than flows in the turbulent regime. Numerous investigations have previously been performed on a single uniformly heated tube operating in the transitional flow regime, however, there exists no data on the influence of a multiple tube inlet condition, as typically found in shell and tube heat exchangers, on the heat transfer characteristics. The purpose of this study was thus to determine the influence of varying tube pitch ratios on the fully developed heat transfer characteristics of three smooth circular horizontal tubes. An experimental set up was designed and built to accommodate a single tube heat exchanger used for validation purposes, and a multiple tube heat exchanger comprising of three identical and equally spaced tubes. Using a DC power supply, the tubes were uniformly heated at 2, 3 and 4 kW/m2 along the length of the test section. The heat transfer characteristics were determined experimentally for outer diameter tube pitch ratios of 1.25 and 1.5 of three 4 mm inner diameter tubes, each 6 m in length for a range of Reynolds numbers of 1 000 to 7 000. Water was used as the test fluid. Using PT100 probes and thermocouples at the inlet, outlet and outer surface of the test section, it was found that the presence of multiple tubes at the inlet of the heat exchanger for a pitch ratio of 1.25 promoted the onset of transition for the centre tube, and sharpened the transition gradient of the outer tubes. This effect noticeably increased with increasing heat flux and was absent at the higher pitch ratio of 1.5.

Download or read book Single phase Heat Transfer and Pressure Drop of Water Cooled at a Constant Wall Temperature Inside Horizontal Circular Smooth and Enhanced Tubes with Different Inlet Configurations in the Transitional Flow Regime written by Jonathan Albert Olivier and published by . This book was released on 2009 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Inlet Effects of Multiple Tubes on the Adiabatic Pressure Drop of Smooth Horizontal Tubes in the Transitional Flow Regime written by Erin Sarah Vause and published by . This book was released on 2015 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: