Download or read book Effects of Hole Separation and Size on Film Cooling of Turbine Blade written by and published by . This book was released on 2006 with total page 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 Effect of Film Hole Shape on Turbine Blade Film Cooling Performance written by and published by . This book was released on 2000 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On Aerothermal Effects of Film Cooling on Turbine Blades with Flow Separation written by Reinaldo Araújo Gomes and published by . This book was released on 2010 with total page 174 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 Heat Transfer in Gas Turbines written by Bengt Sundén and published by Witpress. This book was released on 2001 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: This title presents and reflects current active research on various heat transfer topics and related phenomena in gas turbine systems. It begins with a general introduction to gas turbine heat transfer, before moving on to specific areas.

Download or read book Film Effectiveness Performance for a Shaped Hole on the Suction Side of a Scaled up Turbine Blade written by Jacob Damian Moore and published by . This book was released on 2018 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface curvature has been shown to have significant effects on the film cooling performance of round holes, but the present literature includes very few studies dedicated to curvature’s effects on shaped hole geometries despite their prevalence in turbine blade and vane designs. Experiments were performed on two rows of holes placed on the suction side of a scaled-up gas turbine blade model in a low-Mach-number linear cascade wind tunnel. The test facility was set up to match a high-Mach-number pressure distribution without modifying the blade’s geometry or including contoured end walls to accelerate the flow. By adjusting the positions of the movable walls in the tunnel test section, the suction side pressure distribution could be matched to the design distribution. One row was placed in a region of high convex surface curvature; the other, in a region of low convex curvature. Other geometric and flow parameters near the rows were matched in the design of the experiment, including hole geometry and spacing. The hole geometry was a standard 7-7-7 shaped hole. In addition, local freestream conditions for the rows were measured and set to match as closely as possible. Comparison of the adiabatic effectiveness results from the two rows revealed trends similar to those seen in previous literature for round holes. The high curvature row outperformed the low curvature row at lower coolant injection rates, having wider jets and higher centerline effectiveness. But as the injection rate was increased, the low curvature row surpassed the high curvature row in effectiveness. The driver behind this behavior was the surface-normal pressure gradient that arose from the convex surface curvature. As flow traveled around the surface, centripetal acceleration produced a pressure gradient directed towards the surface, effectively pushing jets toward the blade wall. However, at higher blowing ratios, the jets’ high momenta overcame the effects of this pressure gradient. At these injection rates, the high curvature row’s jets’ trajectories did not follow the surface as it curved away. The high surface curvature exacerbated the adverse effects of jet separation on film cooling performance.

Download or read book Effect of Velocity and Temperature Distribution at the Hole Exit on Film Cooling of Turbine Blades written by Vijay K. Garg and published by . This book was released on 1995 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine and Aeroengine Congress & Exposition, Houston, Texas - June 5-8, 1995.

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 Gas Turbine Blade Cooling written by Chaitanya D Ghodke and published by SAE International. This book was released on 2018-12-10 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas turbines play an extremely important role in fulfilling a variety of power needs and are mainly used for power generation and propulsion applications. The performance and efficiency of gas turbine engines are to a large extent dependent on turbine rotor inlet temperatures: typically, the hotter the better. In gas turbines, the combustion temperature and the fuel efficiency are limited by the heat transfer properties of the turbine blades. However, in pushing the limits of hot gas temperatures while preventing the melting of blade components in high-pressure turbines, the use of effective cooling technologies is critical. Increasing the turbine inlet temperature also increases heat transferred to the turbine blade, and it is possible that the operating temperature could reach far above permissible metal temperature. In such cases, insufficient cooling of turbine blades results in excessive thermal stress on the blades causing premature blade failure. This may bring hazards to the engine's safe operation. Gas Turbine Blade Cooling, edited by Dr. Chaitanya D. Ghodke, offers 10 handpicked SAE International's technical papers, which identify key aspects of turbine blade cooling and help readers understand how this process can improve the performance of turbine hardware.

Download or read book Leading Edge Film Cooling Effects on Turbine Blade Heat Transfer written by Vijay K. Garg and published by . This book was released on 1995 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine and Aeroengine Congress and Exposition, Houston, Texas - June 5-8, 1995.

Download or read book Curvature Effects on the Heat Transfer Performance of Three Dimensional Film Cooling of Gas Turbine Blades written by E. R. G. Eckert and published by . This book was released on 1982 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Film cooling is used extensively for the blades of high-performance, high-temperature gas turbines, especially for aircraft turbines. In this method, a film of coolant is injected into the boundary layer covering the skin of the blades and creating a cool layer which separates the blade surface from the hot gas stream and, in this way, reduces the blade temperature. For best performance the coolant should be injected through a slot or a strip of porous material. This, however, is not possible for turbine blades because of strength considerations, and the coolant is injected through one or several rows of holes. For aircraft gas turbines, air is used as a coolant. The present investigation, therefore, is concerned with the cooling performance of film cooling when cooling air is injected into the boundary through one or two rows of holes. A standard configuration of the coolant holes is used because it has been used in previous investigations and because configurations in actual turbine blades are close to it. The cooling holes are arranged at a distance apart equal to three times the hole diameter. For injection through two rows of holes, the two rows are staggered and the centers of the holes are on the corners of equilateral triangles. The channels which end at the blade skin in the cooling holes are inclined by an angle of 35 deg against the skin surface in the downstream direction.

Download or read book Impacts of Part to Part Variability on Gas Turbine Blade Cooling written by Kelsey Mc Cormack and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas turbine inlet temperatures continue to increase in an effort to improve efficiency. Therefore, effective cooling of hot section components is necessary to reduce deterioration and maintain part life. Despite the best efforts of engine designers, coolant flow blockages or degradation of thermal barrier coatings will nevertheless occur during operation and lead to increased surface temperatures that reduce blade life. This phenomenon is especially prevalent in environments where sand or other small particles are ingested into engines. Part-to-part manufacturing variations also lead to significant changes in geometry relative to design intent that impact the flow and cooling effectiveness of turbine components, even when the deviations are within defined tolerances. This thesis examines part-to-part variations in geometry, flow, and cooling effectiveness for true scale turbine blades. A set of engine-run blades with varying levels of environmental deterioration was operated at engine-relevant conditions and surface temperature was measured using infrared thermography. These measurements were used to calculate cooling effectiveness and expected blade life. Blade flow parameter and cooling effectiveness were both high for blades operated in a benign environment, even though the benign run time blades had the highest run time of the blades measured. Blades operated in a harsh environment not only had lower cooling effectiveness, but also more variation in cooling effectiveness between blades. Film cooling trajectories were calculated for each set of blades tested, and showed that all engine-run blades had a significant reduction in maximum cooling effectiveness behind cooling holes with respect to a set of baseline blades. Cooling effectiveness values were then used to scale surface temperatures up to actual engine operating conditions extracted from the NASA E3 program. While lifing curves from previous literature were able to predict blade temperatures for benign environment blades, surface temperature increased much more than expected for harsh operator blades. A second study analyzed the flow performance and geometry of additively manufactured turbine blades with drilled film cooling holes. A benchtop flow rig was used to characterize flow through the full blade as well as isolated regions of the blade. While partial flow through specific regions of the blade did not match design intent, the total flow through the blade varied by less than 10% between the minimum and maximum flow blades at the design pressure ratio. Computed tomography scans were used to analyze the geometry of cooling features such as film cooling holes, crossover holes, turbulators, and pin fins. Shaped film cooling holes manufactured with a conventional electrical discharge machining (EDM) method were undersized throughout the entire cooling hole. A high-speed EDM method created holes that met design specifications in the metering section, but were also undersized at the hole exit. Additively manufactured features such as turbulators and pin fins were close to design intent shape and size, with the largest variations occurring on downskin surfaces that were unsupported during the build. Roughness was high on both internal and external blade surfaces, particularly for regions with the thinnest walls. This study demonstrated the viability of applying additively manufacturing and advanced hole drill methods to study new turbine cooling technologies at an accelerated timeline and reduced cost.

Download or read book International Symposium on Biological and Environmental Reference Materials written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Inlet Geometry on the Turbine Blade Tip Region Heat Transfer Coefficient and Effectiveness written by and published by . This book was released on 2002 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation of the local film cooling effectiveness and heat transfer coefficient downstream of a row of elongated holes in a simulated axial turbine blade tip is presented. Film cooling is needed to protect the turbine blade tip region from high heat transfer rates, especially when cooling by convection is insufficient to keep the temperature distribution of the blade within the limits required. Accurate heat transfer predictions in this region of the blade are particularly difficult given the dimensionality of the flow and the narrow passage typical of turbine blades. The effect of inlet geometry film cooling injection point and blowing ratio are examined for an injection on the blade tip itself close to the pressure surface corner. Additionally the corner radii between the pressure surface and the tip were varied. The experimental method uses the steady state liquid crystal technique. Film cooling injection provides the tip with a blanket of protection from the hot leakage flow. This extends far downstream of the holes at higher blowing ratios. Inlet curvature provides greater local film cooling effectiveness but it lacks streamwise film cooling coverage. It is important to have direct injection onto the separation bubble for greater lateral film cooling coverage.

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 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: