Download or read book Jet Model for Slot Film Cooling with Effect of Free stream and Coolant Turbulence written by Frederick F. Simon and published by . This book was released on 1986 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Paper written by and published by . This book was released on 1987 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of High Freestream Turbulence on Film Cooling Effectiveness written by and published by . This book was released on 1994 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigated adiabatic wall cooling effectiveness of a single row of film cooling holes injecting into a turbulent flat plate boundary layer below a turbulent, zero pressure gradient freestream. Levels of freestream turbulence (Tu) up to 17.4% were generated using a method which simulates conditions at a gas turbine combustor exit. Film cooling was injected from a single row of five 35 degree slant-hole injectors (length/diameter = 3.5. pitch/diameter = 3.0) at blowing ratios from 0.55 to 1185 and at a nearly constant density ratio (coolant density/freestream density) of 0.95. Film cooling effectiveness data is presented for Tu levels ranging from 0.9% to 17% at a constant freestream Reynolds number based on injection hole diameter of 19000. Results show that elevated levels of freestream turbulence reduce film cooling effectiveness by up to 70% in the region directly downstream of the injection hole due to enhanced mixing. At the same time, high freestream turbulence also produces a 50-100% increase in film cooling effectiveness in the region between injection holds. This is due to accelerated spanwise diffusion of the cooling fluid, which also produces an earlier merger of the coolant jets from adjacent holes.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of In Hole Roughness and High Freestream Turbulence on Film Cooling From a Shaped Hole written by Robert Schroeder and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas turbines are heavily used for electricity generation and aircraft propulsion with a strong desire in both uses to maximize thermal efficiency while maintaining reasonable power output. As a consequence, gas turbines run at high turbine inlet temperatures that require sophisticated cooling technologies to ensure survival of turbine components. One such technology is film cooling with shaped holes, where air is withdrawn from latter stages of the compressor, is bypassed around the combustor, and is eventually ejected out holes in turbine component surfaces. Air ejected from these shaped holes helps maintain components at temperatures lower than flow from the combustor. Many studies have investigated different factors that influence shaped hole performance. However, no studies in open literature have investigated how cooling performance is affected by roughness along interior walls of the shaped hole. The effect of in-hole roughness on shaped hole film cooling was the focus of this research. Investigation of in-hole roughness effects first required the determination of behavior for a shaped hole with smooth walls. A public shaped hole, now used by other investigators as well, was designed with a diffused outlet having 7 degree expansion angles and an area ratio of 2.5. At low freestream turbulence intensity of 0.5%, film cooling adiabatic effectiveness for this smooth hole was found to peak at a blowing ratio of 1.5. Measurements of flowfields and thermal fields revealed causes of this behavior. Blowing ratio increases above 1.5 caused the jet from the smooth hole to penetrate higher into the surrounding mainstream, exhibit a stronger counter-rotating vortex pair, and have narrower contact with the wall than at lower blowing ratios. Experiments performed at high freestream turbulence intensity of 13% revealed dynamics of how freestream turbulence both diluted and laterally spread coolant. At the high blowing ratio of 3 the dilution and spreading were competing effects, such that elevated freestream turbulence did not cause a decrease in area-averaged effectiveness. At the blowing ratio of 1.5, high freestream turbulence caused area-averaged effectiveness to decrease 17% relative to the low freestream turbulence case. Film cooling performance was measured for the shaped hole geometry with several different configurations of in-hole roughness. At low freestream turbulence intensity, in-hole roughness caused decreases in area-averaged adiabatic effectiveness up to 61% relative to the smooth hole performance. These percent decreases in adiabatic effectiveness were more severe with increasing roughness levels and with increasing blowing ratios. Flowfield and thermal field measurements for the configuration with largest roughness size showed that the decrease in adiabatic effectiveness for rough holes as compared to smooth holes was due to thicker boundary layers along the interior walls of the cooling holes. The thicker boundary layers resulted in faster jet core flow, which in turn caused increased penetration of coolant into the mainstream and increased turbulence intensity inside the jet, with both leading to reduced adiabatic effectiveness. Detrimental effects of in-hole roughness persisted at the high freestream turbulence conditions as well.
Download or read book Detailed Film Cooling Measurements on a Cylindrical Leading Edge Model Effect of Free stream Turbulence and Coolant Density written by Srinath V. Ekkad and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine & Aeroengine Congress & Exhibition, Orlando, FL, Jun 2 - Jun 5, 1997.
Download or read book Proceedings Of The International Heat Transfer Conference written by Lee and published by CRC Press. This book was released on 1998-11-01 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt: This year's set of papers includes 23 Keynote Papers and 537 refereed General Papers, in seven volumes. Experts from around the world have combined to address the leading edge of research and practical innovations in convection, combustion, heat exchangers, two-phase flow, and much more. Whether one is involved in mechanical, chemical, nuclear, or energy engineering the quantity, international scope, and high quality of the contents make access to these volumes essential.
Download or read book Effect on Gaseous Film Cooling of Coolant Injection Through Angled Slots and Normal Holes written by S. Stephen Papell and published by . This book was released on 1960 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Scientific and Technical Publications written by and published by . This book was released on 1988 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Free stream Turbulence on Film Cooling written by Cecil J. Marek and published by . This book was released on 1975 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1995 with total page 1774 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Heat Transfer written by and published by Academic Press. This book was released on 2017-11-11 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Heat Transfer, Volume 49 provides in-depth review articles from a broader scope than in traditional journals or texts. Topics covered in this new volume include Heat Transfer in Rotating Cooling Channel, Flow Boiling and Flow Condensation in Reduced Gravity, Advances in Gas Turbine Cooling, and Advanced Heat Transfer Topics in Complex Duct Flows. While the articles in this series will be of great interest to mechanical, chemical and industrial engineers working in the field of heat transfer, the book is also ideal for those in graduate schools or industry, and even non-specialists interested in the latest research. Compiles the expert opinions of leaders in the industry 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 Essential reading for all mechanical, chemical and industrial engineers working in the field of heat transfer, or in graduate schools or industry
Download or read book NASA Scientific and Technical Publications written by and published by . This book was released on 1987 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulence Modelling Approaches written by Konstantin Volkov and published by BoD – Books on Demand. This book was released on 2017-07-26 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate prediction of turbulent flows remains a challenging task despite considerable work in this area and the acceptance of CFD as a design tool. The quality of the CFD calculations of the flows in engineering applications strongly depends on the proper prediction of turbulence phenomena. Investigations of flow instability, heat transfer, skin friction, secondary flows, flow separation, and reattachment effects demand a reliable modelling and simulation of the turbulence, reliable methods, accurate programming, and robust working practices. The current scientific status of simulation of turbulent flows as well as some advances in computational techniques and practical applications of turbulence research is reviewed and considered in the book.
Download or read book Direct and Large Eddy Simulation IX written by Jochen Fröhlich and published by Springer. This book was released on 2015-01-27 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reflects the state of the art of numerical simulation of transitional and turbulent flows and provides an active forum for discussion of recent developments in simulation techniques and understanding of flow physics. Following the tradition of earlier DLES workshops, these papers address numerous theoretical and physical aspects of transitional and turbulent flows. At an applied level it contributes to the solution of problems related to energy production, transportation, magneto-hydrodynamics and the environment. A special session is devoted to quality issues of LES. The ninth Workshop on 'Direct and Large-Eddy Simulation' (DLES-9) was held in Dresden, April 3-5, 2013, organized by the Institute of Fluid Mechanics at Technische Universität Dresden. This book is of interest to scientists and engineers, both at an early level in their career and at more senior levels.
Download or read book Gas Turbine Heat Transfer and Cooling Technology written by Je-Chin Han and published by Taylor & Francis. This book was released on 2012-11-27 with total page 865 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive reference for engineers and researchers, this second edition focuses on gas turbine heat transfer issues and their associated cooling technologies for aircraft and land-based gas turbines. It provides information on state-of-the-art cooling technologies such as advanced turbine blade film cooling and internal cooling schemes. The book also offers updated experimental methods for gas turbine heat transfer and cooling research, as well as advanced computational models for gas turbine heat transfer and cooling performance predictions. The authors provide suggestions for future research within this technology and includes 800 illustrations to help clarify concepts and instruction.
Download or read book 93 1752 93 1799 written by and published by . This book was released on 1992 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
