Download or read book Influence of Mainstream Turbulence and Unsteady Wake on Turbine Blade Heat Transfer written by Luzeng Zhang and published by . This book was released on 1993 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unsteady High Turbulence Effects on Turbine Blade Film Cooling Heat Transfer Performance Using a Transient Liquid Crystal Technique written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-27 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unsteady wake effect, with and without trailing edge ejection, on detailed heat transfer coefficient and film cooling effectiveness distributions is presented for a downstream film-cooled gas turbine blade. Tests were performed on a five-blade linear cascade at an exit Reynolds number of 5.3 x 10(exp 5). Upstream unsteady wakes were simulated using a spoke-wheel type wake generator. Coolant blowing ratio was varied from 0.4 to 1.2; air and CO2 were used as coolants to simulate different density ratios. Surface heat transfer and film effectiveness distributions were obtained using a transient liquid crystal technique; coolant temperature profiles were determined with a cold wire technique. Results show that Nusselt numbers for a film cooled blade are much higher compared to a blade without film injection. Unsteady wake slightly enhances Nusselt numbers but significantly reduces film effectiveness versus no wake cases. Nusselt numbers increase only slic,htly but film cooling, effectiveness increases significantly with increasing, blowing ratio. Higher density coolant (CO2) provides higher effectiveness at higher blowing ratios (M = 1.2) whereas lower density coolant (Air) provides higher 0 effectiveness at lower blowing ratios (M = 0.8). Trailing edge ejection generally has more effect on film effectiveness than on the heat transfer, typically reducing film effectiveness and enhancing heat transfer. Similar data is also presented for a film cooled cylindrical leading edge model. Han, J. C. and Ekkad, S. V. and Du, H. and Teng, S. Glenn Research Center NAG3-1656; RTOP 714-01-4A

Download or read book Unsteady High Turbulence Effects on Turbine Blade Film Cooling Heat Transfer Performance Using a Transient Liquid Crystal Technique written by and published by . This book was released on 2000 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Combined Effects of Reynolds Number Turbulence Intensity and Periodic Unsteady Wake Flow Conditions on Boundary Layer Development and Heat Transfer of a Low Pressure Turbine Blade written by Burak Ozturk and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed experimental investigation has been conducted to provide a detailed insight into the heat transfer and aerodynamic behavior of a separation zone that is generated as a result of boundary layer development along the suction surface of a highly loaded low pressure turbine (LPT) blade. The research experimentally investigates the individual and combined effects of periodic unsteady wake flows and freestream turbulence intensity (Tu) on heat transfer and aerodynamic behavior of the separation zone. Heat transfer experiments were carried out at Reynolds number of 110,000, 150,000, and 250,00 based on the suction surface length and the cascade exit velocity. Aerodynamic experiments were performed at Re = 110,000 and 150,000. For the above Re-numbers, the experimental matrix includes Tus of 1.9%, 3.0%, 8.0%,13.0% and three different unsteady wake frequencies with the steady inlet flow as the reference configuration. Detailed heat transfer and boundary layer measurements are performed with particular attention paid to the heat transfer and aerodynamic behavior of the separation zone at different Tus at steady and periodic unsteady flow conditions. The objectives of the research are (a) to quantify the effect of Tu on the aero-thermal behavior of the separation bubble at steady inlet flow condition, (b) to investigate the combined effects of Tu and the unsteady wake flow on the aero-thermal behavior of the separation bubble, and (c) to provide a complete set of heat transfer and aerodynamic data for numerical simulation that incorporates Navier-Stokes and energy equations. The analysis of the experimental data reveals details of boundary layer separation dynamics which is essential for understanding the physics of the separation phenomenon under periodic unsteady wake flow and different Reynolds number and Tu. To provide a complete picture of the transition process and separation dynamics, extensive intermittency analysis was conducted. Ensemble averaged maximum and minimum intermittency functions were determined leading to the relative intermittency function. In addition, the detailed intermittency analysis reveals that the relative intermittency factor follows a Gaussian distribution confirming the universal character of the relative intermittency function.

Download or read book Effect of Unsteady Wake on Detailed Heat Transfer Coefficient and Film Effectiveness Distributions for a Gas Turbine Blade written by Hui Du 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 An Experimental Investigation of Turbine Blade Heat Transfer and Turbine Blade Trailing Edge Cooling written by Jungho Choi and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This experimental study contains two points; part 1 - turbine blade heat transfer under low Reynolds number flow conditions, and part 2 - trailing edge cooling and heat transfer. The effect of unsteady wake and free stream turbulence on heat transfer and pressure coefficients of a turbine blade was investigated in low Reynolds number flows. The experiments were performed on a five blade linear cascade in a low speed wind tunnel. A spoked wheel type wake generator and two different turbulence grids were employed to generate different levels of the Strouhal number and turbulence intensity, respectively. The cascade inlet Reynolds number based on blade chord length was varied from 15,700 to 105,000, and the Strouhal number was varied from 0 to 2.96 by changing the rotating wake passing frequency (rod speed) and cascade inlet velocity. A thin foil thermocouple instrumented blade was used to determine the surface heat transfer coefficient. A Liquid crystal technique based on hue value detection was used to measure the heat transfer coefficient on a trailing edge film cooling model and internal model of a gas turbine blade. It was also used to determine the film effectiveness on the trailing edge. For the internal model, Reynolds numbers based on the hydraulic diameter of the exit slot and exit velocity were 5,000, 10,000, 20,000, and 30,000 and corresponding coolant-to-mainstream velocity ratios were 0.3, 0.6, 1.2, and 1.8 for the external models, respectively. The experiments were performed at two different designs and each design has several different models such as staggered / inline exit, straight / tapered entrance, and smooth / rib entrance. The compressed air was used in coolant air. A circular turbulence grid was employed to upstream in the wind tunnel and square ribs were employed in the inlet chamber to generate turbulence intensity externally and internally, respectively.

Download or read book Unsteady wake effects on boundary layer transition and heat transfer characteristics of a turbine blade ASME 98 GT 291 written by M. T. Schobeiri and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine & Aeroengine Congress & Exhibition, Stockholm, Sweden, June 2 - June 5, 1998.

Download or read book A Numerical Study of the Effect of Wake Passing on Turbine Blade Film Cooling written by James D. Heidmann and published by . This book was released on 1995 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Gas Turbine Heat Transfer and Cooling Technology Second Edition written by Je-Chin Han and published by CRC Press. This book was released on 2012-11-27 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive reference for engineers and researchers, Gas Turbine Heat Transfer and Cooling Technology, Second Edition has been completely revised and updated to reflect advances in the field made during the past ten years. The second edition retains the format that made the first edition so popular and adds new information mainly based on selected published papers in the open literature. See What’s New in the Second Edition: State-of-the-art cooling technologies such as advanced turbine blade film cooling and internal cooling Modern experimental methods for gas turbine heat transfer and cooling research Advanced computational models for gas turbine heat transfer and cooling performance predictions Suggestions for future research in this critical technology The book discusses the need for turbine cooling, gas turbine heat-transfer problems, and cooling methodology and covers turbine rotor and stator heat-transfer issues, including endwall and blade tip regions under engine conditions, as well as under simulated engine conditions. It then examines turbine rotor and stator blade film cooling and discusses the unsteady high free-stream turbulence effect on simulated cascade airfoils. From here, the book explores impingement cooling, rib-turbulent cooling, pin-fin cooling, and compound and new cooling techniques. It also highlights the effect of rotation on rotor coolant passage heat transfer. Coverage of experimental methods includes heat-transfer and mass-transfer techniques, liquid crystal thermography, optical techniques, as well as flow and thermal measurement techniques. The book concludes with discussions of governing equations and turbulence models and their applications for predicting turbine blade heat transfer and film cooling, and turbine blade internal cooling.

Download or read book Wake Interaction Effects on the Transition Process on Turbine Blades written by OXFORD UNIV (England) DEPT OF ENGINEERING SCIENCE. and published by . This book was released on 1986 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wide bandwidth (100 kHz) heat transfer instrumentation was used to make detailed time resolved measurements on a two dimensional gas turbine rotor cascade blade surface under the influence of simulated unsteady wake and shock passing events. The instrumentation was capable of detecting and tracking naturally occurring transitional turbulent spots confirming the classical model of boundary layer transition. In addition instantaneous large excursions in the surface heat transfer were observed as the simulated wake shock structure from a transonic nozzle guide wave passed over the rotor cascade. The transitional behavior of the blade boundary layer was seen to depend primarily on free stream turbulence and Reynolds number and, away from the direct interaction region, to be relatively unaffected by the wake/shock induced disturbances. Keywords: Gas Turbine Heat Transfer; Unsteady Wake Interactions; Boundary Layer Transition.

Download or read book An Experimental Study of the Effect of Wake Passing on Turbine Blade Film Cooling written by James D. Heidmann and published by . This book was released on 1997 with total page 14 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 The Effect of Wake Passing on Turbine Blade Film Cooling written by James D. Heidmann and published by . This book was released on 1996 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Inlet Turbulence and Rotor stator Interactions on the Aerodynamics and Heat Transfer of a Large scale Rotating Turbine Model Volume 1 written by Robert P. Dring 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 Effect of Film Hole Shape on Turbine Blade Film Cooling Performance written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-30 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The detailed heat transfer coefficient and film cooling effectiveness distributions as well as tile detailed coolant jet temperature profiles on the suction side of a gas turbine blade A,ere measured using a transient liquid crystal image method and a traversing cold wire and a traversing thermocouple probe, respectively. The blade has only one row of film holes near the gill hole portion on the suction side of the blade. The hole geometries studied include standard cylindrical holes and holes with diffuser shaped exit portion (i.e. fanshaped holes and laidback fanshaped holes). Tests were performed on a five-blade linear cascade in a low-speed wind tunnel. The mainstream Reynolds number based on cascade exit velocity was 5.3 x 10(exp 5). Upstream unsteady wakes were simulated using a spoke-wheel type wake generator. The wake Strouhal number was kept at 0 or 0.1. Coolant blowing ratio was varied from 0.4 to 1.2. Results show that both expanded holes have significantly improved thermal protection over the surface downstream of the ejection location, particularly at high blowing ratios. However, the expanded hole injections induce earlier boundary layer transition to turbulence and enhance heat transfer coefficients at the latter part of the blade suction surface. In general, the unsteady wake tends to reduce film cooling effectiveness.Han, J. C. and Teng, S.Glenn Research CenterHEAT TRANSFER COEFFICIENTS; COOLANTS; TEMPERATURE PROFILES; SUCTION; TURBINE BLADES; HEAT MEASUREMENT; FILM COOLING; BOUNDARY LAYER TRANSITION; CASCADE WIND TUNNELS; CYLINDRICAL BODIES; EJECTION; GAS TURBINES; HOLE DISTRIBUTION (MECHANICS); LIQUID CRYSTALS; LOW SPEED; THERMAL PROTECTION; THERMOCOUPLES; WIND TUNNELS

Download or read book Heat Transfer to Turbine Blades with Special Reference to the Effects of Mainstream Turbulence written by A. Brown and published by . This book was released on 1979 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of the Thermal Boundary Condition and Turbulence on Heat Transfer from a Cylinder Flat Plate and Turbine Blade Using the Transient Shroud and Heated coating Techniques written by Robert John Butler and published by . This book was released on 1995 with total page 582 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A General Method for Unsteady Heat Transfer on Turbine Blades written by Tuncer Cebeci and published by . This book was released on 1989 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: