Download or read book Computational Simulation and Analysis of Film Cooling for the Leading edge Model of a Turbine Blade written by and published by . This book was released on 2007 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of interest is the cooling of turbine blades in large gas combustion engines where hot gases from the combustor cause thermal deterioration of the metal turbine blades. A thin-film of coolant flow buffers the hottest parts of the blade surface. Heat transfer on a bluff body and, subsequently, a single-hole cooling problem is solved numerically in two-dimensions. The flow is assumed to be incompressible, and the laminar, steady Navier-Stokes equations are used to obtain the flow solution. Results for the bluff-body heat transfer agree very well with experimental data up to the separation point, and are within 20% of the data thereafter. The film-cooling simulation yielded higher cooling effectiveness due in large part to the use of the two-dimensional model, which treats the hole as a slot with higher coolant mass. Results from the simulations indicate that the Cobalt flow solver is capable of solving complex heat transfer problems.

Download or read book Numerical Simulation of a Film Cooled Turbine Blade Leading Edge Including Heat Transfer Effects written by Laurene D. Dobrowolski and published by . This book was released on 2009 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computations and experiments were run to study heat transfer and overall effectiveness for a simulated turbine blade leading edge. Computational predictions were run for a film cooled leading edge model using a conjugate numerical method to predict the normalized "metal" temperatures for the model. This computational study was done in conjunction with a parallel effort to experimentally determine normalized metal temperatures, i.e. overall effectiveness, using a specially designed high conductivity model. Predictions of overall effectiveness were higher than experimentally measured values in the stagnation region, but lower along the downstream section of the leading edge. Reasons for the differences between computational predictions and experimental measurements were examined. Also of interest was the validity of Taw as the driving temperature for heat transfer into the blade, and this was examined via computations. Overall, this assumption gave reasonable results except near the stagnation line. Experiments were also conducted on a leading edge with no film cooling to gain a better understanding of the additional cooling provided by film cooling. Heat flux was also measured and external and internal heat transfer coefficients were determined. The results showed roughly constant overall effectiveness on the external surface.

Download or read book Computations of Film Cooling for the Leading Edge Region of a Turbine Blade Model written by Pingfan He and published by . This book was released on 1995 with total page 0 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 Three dimensional Numerical Simulation of Film Cooling on a Turbine Blade Leading edge Model written by Douglas Stenger and published by . This book was released on 2009 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present study is a three-dimensional numerical investigation of the effectiveness of film cooling for a turbine blade leading-edge model with both a single and a three-hole cooling configuration. The model used has the same dimensions as those in the experimental investigation of Ou and Rivir (2006). It consists of a half cylinder with a flat after-body, and well represents the leading edge of a turbine blade. The single coolant hole is situated approximately at the spanwise center of the cylindrical model, and makes an angle of 21.5 degrees to the leading edge and 20 degrees to the spanwise direction. For the three-hole configuration, the center hole is positioned the same as the single hole in the single-hole configuration, with the adjacent holes located at a spanwise distance of 37.4 mm on either side of the center hole. Multi-block grids were generated using GridGen, and the flows were simulated using the flow solver Fluent. A highly clustered structured C-grid was developed around the leading edge of the model. The outer unstructured-grid domain represents the wind tunnel as used in the experimental study of Ou and Rivir (2006), and the leading-edge model is located at the center of the domain. Simulations were carried out for blowing ratios, M, ranging from 0.75 to 2.0. Turbulence was represented using the k-? shear-stress transport (SST) model, and the flow was assumed to have a free-stream turbulence intensity of 0.75%. Two types of boundary conditions were used to represent the blade wall: an adiabatic surface, and a conductive surface. The adiabatic-wall results over-predicted the film-cooling effectiveness in the far downstream region for low blowing ratios. Also, in the vicinity of the cooling hole, an increase in blowing ratio resulted in higher film cooling effectiveness than observed in the experiments. It should be noted that the steady RANS-based turbulence model used under-predicts the interaction between the coolant and mainstream flow near the cooling-pipe exit. The conductive-wall results show a much closer agreement with experimental data for film effectiveness as compared to the adiabatic-wall predictions. Simulations were also performed with higher values of turbulence intensity at the cooling-hole inlet, and these predicted the coolant-mainstream interaction and the film-cooling effectiveness more accurately. Finally, a novel concept of pulsing the coolant flow was implemented so as to achieve film-cooling effectiveness equivalent to that with constant cooling, but with reduced overall coolant air, thereby enhancing turbine efficiency. Pulsed cooling with pulsing frequency PF = 5 and 10Hz, and duty cycle DC = 50%, shows the greatest cooling effects. The three-hole cooling results indicate that the 49 mm spanwise distance used for computing the spanwise-averaged values for film-cooling effectiveness accounts for all of the film-coolant spreading provided by the single hole. Also, the neighboring cooling holes contribute little film cooling to the 49 mm spanwise distance. The most significant new finding in this work is that the inclusion of wall conductance is the main factor responsible for reproducing the experimental data.

Download or read book Theoretical Computational and Experimental Solutions to Thermo Fluid Systems written by Muthukumar Palanisamy and published by Springer Nature. This book was released on 2021-03-09 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents select proceedings of the International Conference on Innovations in Thermo-Fluid Engineering and Sciences (ICITFES 2020). It covers topics in theoretical and experimental fluid dynamics, numerical methods in heat transfer and fluid mechanics, different modes of heat transfer, multiphase flow, fluid machinery, fluid power, refrigeration and air conditioning, and cryogenics. The book will be helpful to the researchers, scientists, and professionals working in the field of fluid mechanics and machinery, and thermal engineering.

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 Single hole Film Cooling on a Turbine blade Leading edge Model written by and published by . This book was released on 2008 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Survey of Advantages and Problems Associated with Transpiration Cooling and Film Cooling of Gas turbine Blades written by Ernst Rudolf Georg Eckert and published by . This book was released on 1951 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary: Transpiration and film cooling promise to be effective methods of cooling gas-turbine blades; consequently, analytical and experimental investigations are being conducted to obtain a better understanding of these processes. This report serves as an introduction to these cooling methods, explains the physical processes, and surveys the information available for predicting blade temperatures and heat-transfer rates. In addition, the difficulties encountered in obtaining a uniform blade temperature are discussed, and the possibilities of correcting these difficulties are indicated. Air is the only coolant considered in the application of these cooling methods.

Download or read book Numerical Simulations of Leading Edge Film Cooling Flows for Gas Tubine Airfoils written by Cheryl A. Martin and published by . This book was released on 1997 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computational Methods and Experimental Measurements XVI written by G. M. Carlomagno and published by WIT Press. This book was released on 2013-07-02 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the results of the sixteenth in a biennial series of meetings organised by the Wessex Institute of Technology to facilitate that communication between scientists who perform experiments, researchers who develop computer codes, and those who carry out measurements on prototypes. The conference was first held in 1984. While computer models are now more reliable and better able to represent more realistic problems, experimental measurements need to be conditioned to the requirements of the computational models. Progress of engineering sciences depends on the orderly and progressive concurrent development of all three fields.The papers contained in the book cover such topics as: Computational and experimental methods; Computer interaction and control of experiments; Fluid flow; Structural and stress analysis; Computer methods; Materials characterization; Heat transfer and thermal processes; Data acquisition and signal processing; Advances in measurements and data acquisition; Multiscale modelling; Industrial applications.

Download or read book A Numerical Analysis of Heat Transfer and Effectiveness on Film Cooled Turbine Blade Tip Models written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-15 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational study has been performed to predict the distribution of convective heat transfer coefficient on a simulated blade tip with cooling holes. The purpose of the examination was to assess the ability of a three-dimensional Reynolds-averaged Navier-Stokes solver to predict the rate of tip heat transfer and the distribution of cooling effectiveness. To this end, the simulation of tip clearance flow with blowing of Kim and Metzger was used. The agreement of the computed effectiveness with the data was quite good. The agreement with the heat transfer coefficient was not as good but improved away from the cooling holes. Numerical flow visualization showed that the uniformity of wetting of the surface by the film cooling jet is helped by the reverse flow due to edge separation of the main flow. Ameri, A. A. and Rigby, D. L. Glenn Research Center NASA/CR-1999-209165, NAS 1.26:209165, E-11756

Download or read book A Simulation of Film Cooling in the Leading Edge Region of a Turbine Blade trench Effect on Film Effectiveness from Cylinder in Crossflow written by and published by . This book was released on 2012 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recueil factice d articles de presse concernant Antoni dit de Sceaux funambule written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Turbomachinery written by Earl Logan, Jr. and published by CRC Press. This book was released on 2003-05-01 with total page 829 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building on the success of its predecessor, Handbook of Turbomachinery, Second Edition presents new material on advances in fluid mechanics of turbomachinery, high-speed, rotating, and transient experiments, cooling challenges for constantly increasing gas temperatures, advanced experimental heat transfer and cooling effectiveness techniques, and propagation of wake and pressure disturbances. Completely revised and updated, it offers updated chapters on compressor design, rotor dynamics, and hydraulic turbines and features six new chapters on topics such as aerodynamic instability, flutter prediction, blade modeling in steam turbines, multidisciplinary design optimization.

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 Systematic Study of Shaped hole Film Cooling at the Leading Edge of a Scaled up Turbine Blade written by Jacob Damian Moore and published by . This book was released on 2020 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: The leading-edge regions of turbine vanes and blades require careful attention to their cooling designs because of the high heat loads. External cooling is typically accomplished with dense "showerhead" arrangements of film cooling holes surrounding the stagnation point at the airfoil leading edge. In modern film cooling studies, shaped holes are prevalent in downstream areas of turbine airfoils; however, the literature contains few studies of shaped holes in the showerhead. This leads to a lack of physics-based insight that would lead to the design of high-performing showerhead arrays. This study examined the performance and physical behavior of several showerhead arrangements at the leading edge of a scaled-up turbine blade. A low-speed linear cascade test section was used to simulate the blade environment, and experiments were conducted at scaled engine-realistic conditions. First, the cooling performances of baseline cylindrical and shaped hole designs were compared. The shaped hole design mimicked a standard design in the literature for flat plate studies but with some modifications expected to improve performance specifically at the leading edge. The result was a novel off-center, elliptically-expanding hole. Adiabatic effectiveness and thermal field measurements revealed that the baseline shaped hole had 20-100% performance due to better jet attachment, stemming from its diffuser, which effectively decreased the exit momenta of the coolant jets. The expansion area ratio was increased by 40% for a subsequent design to gauge sensitivity to this parameter; but, surprisingly, the performances of the new design and of the baseline one were nearly identical. A third shaped hole design with a 45% larger breakout area but an identical expansion area resulted in slightly worse performance than either, highlighting the detrimental effect of increasing breakout area and expansion angle. These experiments informed a new proposed scaling parameter incorporating both of these areas and their counteracting effects to predict shaped hole performance in the showerhead. The highest performing design of the group was then tested with an engine-realistic impingement coolant feed, for which performance was overall similar. Supplemental thermal fields using this configuration were performed to construct a 3D representation of the flow field in the showerhead region

Download or read book Modelling and Simulation of Turbulent Heat Transfer written by B. Sundén and published by WIT Press. This book was released on 2005-02-21 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing invaluable information for both graduate researchers and R & D engineers in industry and consultancy, this book focuses on the modelling and simulation of fluid flow and thermal transport phenomena in turbulent convective flows. Its overall objective is to present state-of-the-art knowledge in order to predict turbulent heat transfer processes in fundamental and idealized flows as well as in engineering applications. The chapters, which are invited contributions from some of the most prominent scientists in this field, cover a wide range of topics and follow a unified outline and presentation to aid accessibility.