Download or read book Film Cooling Effectiveness on a Turbine Vane in Transonic Conditions written by Isabella Gayoso and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this experiment, measurements of the overall cooling effectiveness for a film cooled turbine vane airfoil in a high-speed cascade were obtained using infrared thermography. The vane used was the NASA C3X with impingement holes (showerhead cooling) and convective cooling holes on both the suction and pressure side. This work was done in the Mechanical Engineering Department's Experimental and Computational Convection Lab and used the high-speed cascade capability of the lab. The rationale for conducting this work was to obtain experimental data on film cooling effectiveness in a turbine vane in engine-like conditions at transonic speeds. Previous work has been done at subsonic speeds, but few pieces of literature examine this parameter at transonic speeds. The data can then be used to validate or compare to CFD models and to better understand what happens to the vane temperature distribution during engine operation. This understanding could inform the design of film cooling holes to reduce thermal strain "hot spots" which lead to failure of the vane. The results showed that trends for values of overall film effectiveness were as expected in this experiment, such as increases in blowing ratio correlating to increases in overall film effectiveness. However, the blowing ratios used in this study were not as high as values studied previously, indicating a need for more data on overall film effectiveness at transonic speeds.

Download or read book Numerical Study of Film Cooling Influence on Performance of Transonic Vane Cascade written by Ahmad Mahmoud Alameldin and published by . This book was released on 2014 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Gas turbines are a major contributor to world power generation with applications ranging from electricity production to aircrafts propulsion. Their efficiency is subject to continuous research. A gas turbine's overall efficiency is directly proportional to flow inlet temperature. Various methods are implemented to protect hot gas path components from mainstream flow well above their melting temperature, namely, heat resistant coatings, internal cooling and film cooling. The latter is the subject of this work. A 3-D Computational Fluid Dynamics (CFD) model is solved using ANSYS CFX software and compared to experimental measurements of film cooled transonic vane cascade operating at a Mach number of 0.89; the experimental data used for validation is provided by Heat and Power Technology Department of the Royal Institute of Technology (Kungliga Tekniska Hogskolan, KTH) of Stockholm, Sweden. A new approach was used to model the film cooling holes, omitting the need to model both the coolant plenum and cooling tubes, resulting in 180% reduction in grid size and attributed computational cost interpreted in 300% saving in computation time. The new approach was validated on a basic flow problem (flat plate film cooling) and was found to give good agreement with experimental measurements of velocity and temperature at a blowing ratio (BR) of 1 and 2; the experimental data for the flat plate was provided by NASA's Glenn Research Center. The numerical simulation of the cooled vane cascade was compared to experimental measurements for different cooling configurations and different BRs. a) One row on pressure side at BR = 0.8, 0.96 and 2.5. b) Two rows on suction side (location 1) at BR = 0.8, 1.4 and 2.5. c) Two rows on suction side (location 2) at BR = 0.8. And d) Showerhead cooled vane at BR ranges between 1.98 and 5.84. The coolant was applied at the same temperature as the mainstream, to match experimental conditions. A good agreement with the experimental measurements was obtained for exit flow angle, vorticity downstream of the vane, pressure coefficients and aerodynamic loss. The proposed approach of coolant injection modeling is shown to yield reliable results, within the uncertainty of the measurements in most cases. Along with lower computational cost compared to conventional film cooling modeling approach, the new approach is recommended for further analysis for aero and thermal vane cascade flows.

Download or read book The Influence of Film Cooling and Inlet Temperature Profile on Heat Transfer for the Vane Row of a 1 1 2 Stage Transonic High pressure Turbine written by Harika Senem Kahveci and published by . This book was released on 2010 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The goal of this research was to establish an extensive database for typical engine hardware with a film-cooled first stage vane, which represents the foundation for future turbomachinery film cooling modeling and component heat transfer studies. Until this time, such a database was not available within the gas turbine industry. Accordingly, the study focuses on determination of the local heat flux for the airfoil and endwall surfaces of the vane row of a fully-cooled turbine stage. The measurements were performed at the Ohio State University Gas Turbine Laboratory using the Turbine Test Facility. The full-scale rotating 1 and 1/2 turbine stage is operated at the proper corrected engine design conditions: Flow Function (FF), corrected speed, stage Pressure Ratio (PR), and temperature ratios of gas to wall and gas to coolant. The primary measurements of temperature, pressure, and heat flux are repeated for different vane inlet temperature profiles and different vane cooling flows to establish an understanding of the influence of film cooling on local heat transfer. Double-sided Kapton heat-flux gauges are used for heat-flux measurements at different span locations along the airfoil surfaces and along the inner endwall. The cooling scheme consists of numerous cooling holes located on the endwalls, at the airfoil leading edge, on the airfoil pressure and suction surfaces, and at the trailing edge, resulting in a fully cooled first stage vane. The unique film-cooled endwall heat transfer data demonstrated in contour plots reveals insight to the complex flow behavior that is dominant in this region, which becomes even more complicated with the addition of coolant. Varying profile shapes resulted in significant heat transfer variations in a growing fashion towards the trailing edge region, which increased in magnitude when there is no coolant supply. The largest cooling effect is observed on 5% span pressure surface and at the inner endwall region. Heat transfer decreases from tip towards hub with addition of cooling. However, a similar decrease is not observed at the inner endwall region by doing so, which suggests excess coolant once beyond an optimum blowing ratio. Cooling flow rate and temperature profile shape affect the distributions on the airfoil surface very similarly, the latter observed more clearly at the endwall region. The vane outer cooling effect is comparable to the combined coolant effect at all surfaces, while no impact of purge flow is observed. Aligning the hot streaks with the vane leading edge lowered heat transfer compared to mid-passage alignment at the mid-span suction surface and through the endwall passage, and increased it at the endwall exit, while the pressure surface is found to be insensitive to this switch. Comparison with a previous research program with the un-cooled version of the vane gave good agreement on the pressure surface and at the endwall, but significantly lower heat transfer on the suction surface due to ingestion of the hot flow through the cooling holes when there is no cooling.

Download or read book Film cooling on the pressure surface of a turbine vane written by James W. Gauntner and published by . This book was released on 1977 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Leading Edge and Downstream Film Cooling on Turbine Vane Heat Transfer written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-23 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: The progress under contract NAS3-24619 toward the goal of establishing a relevant data base for use in improving the predictive design capabilities for external heat transfer to turbine vanes, including the effect of downstream film cooling with and without leading edge showerhead film cooling. Experimental measurements were made in a two-dimensional cascade previously used to obtain vane surface heat transfer distributions on nonfilm cooled airfoils under contract NAS3-22761 and leading edge showerhead film cooled airfoils under contract NAS3-23695. The principal independent parameters (Mach number, Reynolds number, turbulence, wall-to-gas temperature ratio, coolant-to-gas temperature ratio, and coolant-to-gas pressure ratio) were maintained over ranges consistent with actual engine conditions and the test matrix was structured to provide an assessment of the independent influence of parameters of interest, namely, exit Mach number, exit Reynolds number, coolant-to-gas temperature ratio, and coolant-to-gas pressure ratio. Data provide a data base for downstream film cooled turbine vanes and extends the data bases generated in the two previous studies. The vane external heat transfer obtained indicate that considerable cooling benefits can be achieved by utilizing downstream film cooling. The data obtained and presented illustrate the interaction of the variables and should provide the airfoil designer and computational analyst the information required to improve heat transfer design capabilities for film cooled turbine airfoils. Hylton, L. D. and Nirmalan, V. and Sultanian, B. K. and Kaufman, R. M. Unspecified Center EQUIPMENT SPECIFICATIONS; FILM COOLING; HEAT TRANSFER; LEADING EDGES; STRUCTURAL DESIGN; VANES; AIRCRAFT ENGINES; CASCADE FLOW; DATA PROCESSING; GAS TURBINES; HIGH TEMPERATURE; PARAMETERIZATION; TWO DIMENSIONAL FLOW...

Download or read book Comparison of Cooling Effectiveness of Turbine Vanes with and Without Film Cooling written by and published by . This book was released on 1974 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Film Injection Angle on Turbine Vane Cooling written by James W. Guantner and published by . This book was released on 1977 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Adverse Effect of Film Cooling on the Suction Surface of a Turbine Vane written by Herbert J. Gladden and published by . This book was released on 1974 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Film Injection Angle on Turbine Vane Cooling written by James W. Gauntner and published by . This book was released on 1977 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sweeping Jet Film Cooling written by Mohammad Arif Hossain and published by . This book was released on 2020 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas turbine is an integrated part of modern aviation and power generation industry. The thermal efficiency of a gas turbine strongly depends on the turbine inlet temperature (TIT), and the turbine designers are continuously pushing the TIT to a higher value. Due to the increased freedom in additive manufacturing, the complex internal and external geometries of the turbine blade can be leveraged to utilize innovative cooling designs to address some of the shortcomings of current cooling technologies. The sweeping jet film cooling has shown some promise to be an effective method of cooling where the coolant can be brought very close to the blade surface due to its sweeping nature. A series of experiments were performed using a row of fluidic oscillators on a flat plate. Adiabatic cooling effectiveness, convective heat transfer coefficient, thermal field, and discharge coefficient were measured over a range of blowing ratios and freestream turbulence. Results were compared with a conventional shaped hole (777-hole), and the sweeping jet hole shows improved cooling performance in the lateral direction. Numerical simulation also confirmed that the sweeping jet creates two alternating vortices that do not have mutual interaction in time. When the jet sweeps to one side of the hole exit, it acts as a vortex generator as it interacts with the mainstream ow. This prevents the formation of the counter-rotating vortex pair (CRVP) and allows the coolant to spread in the lateral direction. The results obtained from the low speed at plate tests were utilized to design the sweeping jet film cooling hole for more representative turbine vane geometry. Experiments were performed in a low-speed linear cascade facility. Results showed that the sweeping jet hole has higher cooling effectiveness in the near hole region compared to the shaped hole at high blowing ratios. Next, a detailed experimental investigation of sweeping jet film cooling on the suction surface of a near engine scale transonic nozzle guide vane at an engine relevant Mach number (Ma = 0.8) and Reynolds number (Re = 1x10e6) to determine the effect of compressibility. The heat transfer measurements were conducted with a transient IR method, and the convective heat transfer coefficient (HTC) and adiabatic film cooling effectiveness were estimated using a dual linear regression technique (DLRT). Aerodynamic loss measurements were also performed at an exit plane downstream of the vane cascade. Finally, a comprehensive design integration of sweeping jet film hole was carried out in a Direct Metal Laser Sintering (DMLS) enabled engine scale nozzle guide vane and experimental investigation of overall cooling effectiveness at engine relevant temperature conditions were assessed. The systematic evolution of a sweeping jet film cooling hole design from a large scale flat plate to an engine scale nozzle guide vane has been presented.

Download or read book An Experimental and Numerical Study of Secondary Flows and Film Cooling Effectiveness in a Transonic Cascade written by James C. Kullberg and published by . This book was released on 2011 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many studies have been published on the subject of film cooling, but because of the difficulty and expense of simulating turbine realistic conditions, many authors introduce vast simplifications such as low speed conditions or linear cascades. These simplifications do not adequately represent the behavior of a turbine and therefore their results are of limited use. This study attempts to eliminate many of those simplifications.

Download or read book Effects of Leading Edge Film Cooling and Surface Roughness on the Downstream Film Cooling Along a Transonic Turbine Blade for Low and High Free Stream Turbulence written by and published by . This book was released on 2008 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report is the culmination of a two year effort to demonstrate the capability for performing near wall high resolution Time Resolved Particle Image Velocimetry (TRDPIV) measurements in a transonic turbine. Performing TRDPIV in high speed wall bounded flows with high resolution/magnification often posses significant difficulties. For this reason, two preliminary studies where conducted in order to further understand the challenges that would be present in this type of environment. Hardware and algorithm advancements and developments ultimately enabled performing TRDPIV in the transonic cascade facility. However, high pressure, high speed and the turbine blade complex geometries (high curvature and acceleration) significantly inhibit our ability to deliver homogeneous distribution of flow tracers, especially in the near wall region resulting in low quality measurements and regions with randomly missing data. In addition to our experimental results this effort delivers a novel advanced data reconstruction methodology based on proper orthogonal decomposition that was developed to overcome the aforementioned limitation. The following report documents in detail the methods and results generated throughout this effort.

Download or read book Experimentation Validation and Uncertainty Analysis for Engineers written by Hugh W. Coleman and published by John Wiley & Sons. This book was released on 2018-04-09 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: Helps engineers and scientists assess and manage uncertainty at all stages of experimentation and validation of simulations Fully updated from its previous edition, Experimentation, Validation, and Uncertainty Analysis for Engineers, Fourth Edition includes expanded coverage and new examples of applying the Monte Carlo Method (MCM) in performing uncertainty analyses. Presenting the current, internationally accepted methodology from ISO, ANSI, and ASME standards for propagating uncertainties using both the MCM and the Taylor Series Method (TSM), it provides a logical approach to experimentation and validation through the application of uncertainty analysis in the planning, design, construction, debugging, execution, data analysis, and reporting phases of experimental and validation programs. It also illustrates how to use a spreadsheet approach to apply the MCM and the TSM, based on the authors’ experience in applying uncertainty analysis in complex, large-scale testing of real engineering systems. Experimentation, Validation, and Uncertainty Analysis for Engineers, Fourth Edition includes examples throughout, contains end of chapter problems, and is accompanied by the authors’ website www.uncertainty-analysis.com. Guides readers through all aspects of experimentation, validation, and uncertainty analysis Emphasizes the use of the Monte Carlo Method in performing uncertainty analysis Includes complete new examples throughout Features workable problems at the end of chapters Experimentation, Validation, and Uncertainty Analysis for Engineers, Fourth Edition is an ideal text and guide for researchers, engineers, and graduate and senior undergraduate students in engineering and science disciplines. Knowledge of the material in this Fourth Edition is a must for those involved in executing or managing experimental programs or validating models and simulations.

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 Detailed film cooling effectiveness and three component velocity field measurements on a first stage turbine vane subject to high freestream turbulence written by Marcus Damian Polanka and published by . This book was released on 1999 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Prediction and Measurement of Film Cooling Effectiveness for a First stage Turbine Vane Shroud written by D. Granser and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: After compressor discharge air has initially been used to cool the heat shields of the hot gas inlet casing, it can subsequently be employed for film cooling of the first-stage vane shrouds. Since the flow field near these shrouds is three-dimensional, the film cooling effectiveness cannot be predicted correctly by common two-dimensional codes. The secondary flow transports the film from the pressure side to the suction side where it can even climb up the airfoil to cool its trailing section. Such film cooling effectiveness was first investigated experimentally in a linear vane cascade at atmospheric pressure. The temperatures and static pressure levels at the adiabatic shrouds, as well as the temperature measurements within the vane cascade, are reported for different cooling film blowing rates. In addition, the secondary flow was analysed numerically using a partially-parabolic computer code for 3D viscous flows. It involves mutual interaction of the boundary layer with the mainstream. The secondary flow can also be modelled with this algorithm, which requires less numerical effort than solving the fully 3D elliptic flow equations. The numerical results of the experiment and numerical predictions are compared. In addition, the application of these results to a high-temperature gas turbine is presented.

Download or read book Flow Visualization of Discrete hole Film Cooling with Spanwise Injection Over a Cylinder written by Louis M. Russell and published by . This book was released on 1979 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: