Download or read book 3 D Numerical Simulation of the Flow Through a Turbine Blade Cascade with Cooling Injection at the Leading Edge written by Dieter Bohn and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine and Aeroengine Congress &Exhibition Birmingham, UK - June 10-13, 1996.

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 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 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 Influence of Blade Leading Edge Geometry and Upstream Blowing on the Heat mass Transfer in a Turbine Cascade written by Marco Papa and published by . This book was released on 2006 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Heat Transfer in a Turbine Cascade written by and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of Flow in Turbine Blade Film Cooling written by Saravanakanthan Rajendran and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of Turbine Blade Heat Transfer Using Two equation Turbulence Models written by Abdul Hafid M. Elfaghi and published by . This book was released on 2000 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of high performance gas turbines requires high turbine inlet temperatures that can lead to severe thermal stresses in the turbine blades, particularly in the first stages of the turbine. Therefore, the major objective of gas- turbine designers is to determine the thermal and aero-dynamical characteristics of the turbulent flow in the turbine cascade. This work is a numerical simulation of fluid flow and heat transfer in the turbine blade using different two-equation turbulence models. The turbulence models used here were based on the eddy viscosity concept, which determined the turbulent viscosity through time-averaged Navier-Stokes differential equations. The most widely accepted turbulence models are the two-equation models, which involves the solution of two transport equations for the turbulent kinetic energy, k, and its rate of dissipation, & or In the present simulation, four two-equation turbulence models were used, the standard k-& model, the modified Chen-Kim k-& model, RNG model and Wilcox standard k - OJ turbulence model. A comparison between the turbulence models and their predictions of the heat flux on the blade were carried out. The results were also compared with the available experimental results obtained from a research carried out by Arts et at. (1990) at the von Karman Institute of Fluid Dynamics (VKI). The simulation was performed using the general-purpose computational fluid dynamics code, PHOENICS, which solved the governing fluid flow and heat transfer equations. An H-type, body-fitted-co-ordinate (BFC) grid was used and upstream and downstream periodic conditions were specified. The grid system used was, sufficiently fine and the results were grid independent. All models demonstrated good heat transfer predictions for the pressure side except close to the leading edge. On the suction side, standard model over-predicted the heat transfer, whereas Chen-Kim, RNG and k - OJ models captured the overall behaviour quite well. Unlike k - OJ model, all k - & models generated very high turbulence levels in the stagnation point regions, which gave rise to the heat transfer rates close to the leading edge.

Download or read book Numerical Simulation of Turbine Blade Cooling with Respect to Blade Heat Conduction in Inlet Temperature Profiles written by A. Heselhaus 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 Cooling air Injection Into Secondary Flow and Loss Fields Within a Linear Turbine Cascade written by A. Yamamoto and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to understand overall performance and internal flows of air-cooled turbine blade rows, flows in a model linear cascade were surveyed with secondary air injection from various locations of the blade surfaces. The secondary air interacted with the cascade passage vortices and changed the loss distribution significantly. The cascade overall loss decreased when the air was injected along the mainstream and increased when the air was injected against the mainstream from some locations of the blade leading edge. Effects on overall kinetic energy of the secondary flows and on the cascade outlet flow angle were also discussed in this paper.

Download or read book ASME Technical Papers written by and published by . This book was released on 2001 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Investigation of Air cooled Turbine Blades in Turbojet Engine written by Herman H. Ellerbrock (Jr.) and published by . This book was released on 1951 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Low Reynold Number Turbine Blade Cascade Calculations written by Richard Byram Rivir and published by . This book was released on 1996 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Steady state Stress Relaxation Analysis of Turbine Blade Cooling Designs written by Albert Kaufman and published by . This book was released on 1969 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Numerical Analysis of 3D Flow in a Transonic Turbine Cascade Facility for Aerodynamic Loss Minimization written by Nicholas Herwig and published by . This book was released on 2013 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Investigation of Air cooled Turbine Blades in Turbojet Engine written by Vernon L. Arne and published by . This book was released on 1951 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: