Download or read book Effects of Turbulence Promoters on Heat Transfer Rates and Pumping Power written by Elton Foster Hammond and published by . This book was released on 1948 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurement of Heat Transfer and Pressure Drop in Rectangular Channels with Turbulence Promoters written by J. C. Han and published by . This book was released on 1986 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: Periodic rib turbulators have been used in advanced turbine cooling designs to enhance the internal heat transfer. The objective of the present project was to investigate the combined effects of the rib angle of attack and the channel aspect ratio on the local heat transfer and pressure drop in rectangular channels with two opposite ribbed walls for Reynolds number varied from 10,000 to 60,000. The channel aspect ratio (W/H) was varied from 1 to 2 to 4. The rib angel of attack (alpha) was varied from 90 to 60 to 45 to 30 deg. The highly detailed heat transfer coefficient distribution on both the smooth side and the ribbed side walls from the channel sharp entrance to the downstream region were measured. The results showed that, in the square channel, the heat transfer for the slant ribs (alpha = 30 -45 deg) was about 30 percent higher than that the transverse ribs (alpha = 90 deg) for a constant pumping power. However, in the rectangular channels (W/H = 2 and 4, ribs on W side), the heat transfer at alpha = 30 -45 deg was only about 5 percent higher than 90 deg. The average heat transfer and friction correlations were developed to account for rib spacing, rib angle, and channel aspect ratio over the range of roughness Reynolds number.
Download or read book Heat Transfer and Pressure Drop in Blade Cooling Channels with Turbulence Promoters written by J. C. Han and published by . This book was released on 1984 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Repeated rib roughness elements have been used in advanced turbine cooling designs to enhance the internal heat transfer. Often the ribs are perpendicular to the main flow direction so that they have an angle-of-attack of 90 deg. The objective of the project was to investigate the effect of rib angle-of-attack on the pressure drop and the average heat transfer coefficients in a square duct with two opposite rib-roughned walls for Reynolds number varied from 8000 to 80,000. The rib height-to-equivalent diameter ratio (e/D) was kept at a constant value of 0.063, the rib pitch-to-height ratio (P/e) was varied from 10 to 20, and the rib angle-of-attack (alpha) was varied from 90 deg to 60 deg to 45 deg to 30 deg respectively. Two types of entrance conditions were examined, namely, long duct and sudden contraction. The heat transfer coefficient distribution on the smooth side wall and the rough side wall at the entrance and the fully developed regions were measured. Thermal performance comparison indicated that the pumping power requirement for the rib with an oblique angle to the flow (alpha = 45 deg to 30 deg) was about 20 to 50 percent lower than the rib with a 90 deg angle to the flow for a given heat transfer duty.
Download or read book THE EFFECT OF AXIAL TURBULENCE PROMOTERS ON HEAT TRANSFER AND PRESSURE DROP INSIDE A TUBE written by LAWRENCE BOYD EVANS and published by . This book was released on 1962 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Heat Transfer Fluid Mechanics and Thermodynamics 1993 written by M.D. Kelleher and published by Elsevier. This book was released on 2012-12-02 with total page 1002 pages. Available in PDF, EPUB and Kindle. Book excerpt: The papers contained in this volume reflect the ingenuity and originality of experimental work in the areas of fluid mechanics, heat transfer and thermodynamics. The contributors are drawn from 27 countries which indicates how well the worldwide scientific community is networked. The papers cover a broad spectrum from the experimental investigation of complex fundamental physical phenomena to the study of practical devices and applications. A uniform outline and method of presentation has been used for each paper.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1973 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research and Development Progress Report written by United States. Office of Saline Water and published by . This book was released on 1969 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Turbulence Promotors on the Rate of Heat Transfer and the Pressure Drop in Straight Tubes written by David Margolis and published by . This book was released on 1957 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analogy Between Mass and Heat Transfer with Turbulent Flow written by Edmund E. Callaghan and published by . This book was released on 1953 with total page 724 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analysis of combined heat and mass transfer from a flat plate has been made in terms of Prandtl's simpified physical concept of the turbulent boundary layer. The results of the analysis show that tor conditioins of reasonably small heat and mass transfer, the ratio of the mass- and heat-transfer coefficients is dependent on the Reynolds number of the boundary layer, the Prandtl number of the medium of diffusion, and the Schmidt number of the diffusing fluid in the medium of diffusion. For the particular case of water evaporating into air, the ratio of mass-transfer coefficient to heat-transfer coefficient is found to be slightly greater than unity.
Download or read book Enhancement of the Thermal Performance of Solar Heat Exchangers with Porous Inserts written by Louis Cramer and published by . This book was released on 1967 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: For high thermal performance and effectiveness, the flat plate heat exchangers and cooling channels are designed based on the three basic criteria: (i) small heat transfer area or large surface area to volume ratio, (ii) high heat transfer rate, and (iii) small pumping power. Numerous amounts of research have been dedicated to the notion of enhancing the convective heat transfer inside the channels of a heat exchanger. Recently, the internal porous fins and porous foams of high thermal conductivity have gained considerable attentions in the research and development for their light weight, reduced fluid pumping power requirements, and high heat transfer characteristics. The results from the investigations show the enhancement of heat transfer coefficients and friction factors with the wavy screens relative to those in a smooth channel. This experimental research project aims to investigate the effects of the geometrical properties such the amplitude, period, and porosity of wavy porous mesh screen insert may have on the thermal performance of a heat exchanger and quantify the thermal performance of the channel employing the wavy porous screens for a wide range of applications at low to high Reynolds numbers. The friction factors, and heat transfer are measured in a rectangular channel when sinusoidal screen inserts are employed as turbulence promoters. The screen is made from porous mesh of flat metal screen available commercially. Two mesh screens are employed; one with a 68% porosity and one with a 48% porosity. Both mesh screens have a square shape pore and is delivered as a spool of material. The period of the screen is bent into the wavy mesh screen using a jig with two jaws. The screen wave vector is placed normal to the mean flow of the channel and allowed the peaks of the wave to make only line contact with the two larger side walls of the rectangular channel. The inlet Reynolds number for the experiments covered all three flow regimes: laminar, transition and turbulent. The measurements include the static pressure drop and wall temperature distributions along the channel. For the heat transfer experiments, the parallel walls of the channel touching the screen peaks are heated with a constant heat flux to simulate the channels in a flat plate heat exchanger. Heat transfer experiments are also obtained with one heated wall with a constant heat flux to simulate the conditions of a single channel heat exchanger employed in solar heaters and electronic cooling. Baseline data in a smooth channel without the screen inserts are also measured for comparisons with the data obtained in the same channel with the screen insert. The results on friction factors and heat transfer coefficients are then presented as ratios of data from the screen channel to the smooth channel to provide the performance of the screen channel relative to the smooth channel. The data and ratios are also presented in such a manner that the effect of change in porosity, period and amplitude of the screen insert could be studied. The sinusoidal screen inserts in the channels of a flat plate heat exchanger can provide desirable effects on the heat transfer enhancements (Nu/Nu0 > 1.0) only for the range of Reynolds number tested. The wire diameter of the mesh screen can significantly influence the thermal performance and pressure penalty provided by the wavy screen based on the present investigations and Mahmood et al. [18]. The present results are thus beneficial to the design of porous inserts for the heat exchangers operating over a wide range of flow rates. The effects of screen porosity and wave period are strong only on the efficiency index. The present results thus indicate the viability of the wavy porous inserts for the heat exchangers.
Download or read book Encyclopedia of Renewable Energy Sustainability and the Environment written by and published by Elsevier. This book was released on 2024-10-01 with total page 4061 pages. Available in PDF, EPUB and Kindle. Book excerpt: Encyclopedia of Renewable Energy, Sustainability and the Environment, Four Volume Set comprehensively covers all renewable energy resources, including wind, solar, hydro, biomass, geothermal energy, and nuclear power, to name a few. In addition to covering the breadth of renewable energy resources at a fundamental level, this encyclopedia delves into the utilization and ideal applications of each resource and assesses them from environmental, economic, and policy standpoints. This book will serve as an ideal introduction to any renewable energy source for students, while also allowing them to learn about a topic in more depth and explore related topics, all in a single resource. Instructors, researchers, and industry professionals will also benefit from this comprehensive reference. Covers all renewable energy technologies in one comprehensive resource“/li> Details renewable energies’ processes, from production to utilization in a single encyclopedia Organizes topics into concise, consistently formatted chapters, perfect for readers who are new to the field Assesses economic challenges faced to implement each type of renewable energy Addresses the challenges of replacing fossil fuels with renewables and covers the environmental impacts of each renewable energy
Download or read book The CRC Handbook of Mechanical Engineering written by D. Yogi Goswami and published by CRC Press. This book was released on 2004-09-29 with total page 2690 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of this standard-setting handbook provides and all-encompassing reference for the practicing engineer in industry, government, and academia, with relevant background and up-to-date information on the most important topics of modern mechanical engineering. These topics include modern manufacturing and design, robotics, computer engineering, environmental engineering, economics, patent law, and communication/information systems. The final chapter and appendix provide information regarding physical properties and mathematical and computational methods. New topics include nanotechnology, MEMS, electronic packaging, global climate change, electric and hybrid vehicles, and bioengineering.
Download or read book Journal of Heat Transfer written by and published by . This book was released on 1992 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Symposium on Particle fluid Interactions written by U.S. Atomic Energy Commission and published by . This book was released on 1960 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book TID written by and published by . This book was released on 1952 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer with Turbulence Promoters written by Lawrence Arthur Greenberg and published by . This book was released on 1949 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
