Download or read book Turbulent Spot Characterization and the Modeling of Transitional Heat Transfer in Turbines written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimum design of gas turbine blades depends on accurate prediction of boundary layer transition. The purpose of this research is to obtain more information on the generation. propagation and coalescence of turbulent spots in a transitional boundary layer and examine the effects of free stream turbulence pressure gradient and cross flow. Experimental data from this study may be used to improve existing CFD models, allowing designers to make more accurate predictions of transitional heat transfer in turbines.
Download or read book Modeling of the Heat Transfer in Bypass Transitional Boundary layer Flows written by Frederick F. Simon and published by . This book was released on 1991 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Progress in Modeling of Laminar to Turbulent Transition on Turbine Vanes and Blades written by and published by . This book was released on 1996 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Research Program for Improving Heat Transfer Prediction for the Laminar to Turbulent Transition Region of Turbine Vanes blades written by Frederick F. Simon and published by . This book was released on 1993 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mach Number Effects on Turbine Blade Transition Length Prediction written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-12-29 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of a Mach number correction on a model for predicting the length of transition was investigated. The transition length decreases as the turbulent spot production rate increases. Much of the data for predicting the spot production rate comes from low speed flow experiments. Recent data and analysis showed that the spot production rate is affected by Mach number. The degree of agreement between analysis and data for turbine blade heat transfer without film cooling is strongly dependent of accurately predicting the length of transition. Consequently, turbine blade heat transfer data sets were used to validate a transition length turbulence model. A method for modifying models for the length of transition to account for Mach number effects is presented. The modification was made to two transition length models. The modified models were incorporated into the two-dimensional Navier-Stokes code, RVCQ3D. Comparisons were made between predicted and measured midspan surface heat transfer for stator and rotor turbine blades. The results showed that accounting for Mach number effects significantly improved the agreement with the experimental data. Boyle, R. J. and Simon, F. F. Glenn Research Center NASA/TM-1998-208404, NAS 1.15:208404, E-11237, Rept-98-GT-367 RTOP 523-26-13...
Download or read book Modeling of the Heat Transfer in Bypass Transitional Boundary layer Flows written by Frederick F. Simon and published by . This book was released on 1991 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two equation Low Reynolds number Turbulence Modeling of Transitional Boundary Layer Flows Characteristic of Gas Turbine Blades written by Rodney C. Schmidt and published by . This book was released on 1988 with total page 344 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 NASA Technical Paper written by United States. National Aeronautics and Space Administration and published by . This book was released on 1991 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Paper written by and published by . This book was released on 1991 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transition in Turbines written by and published by . This book was released on 1985 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer Augmentation in Turbulent Flows written by Antanas Pedišius and published by . This book was released on 1995 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent flow is the most common form of motion of liquids and gases playing the role of the heat-transfer medium in thermal systems. The complexity of turbulent flow and the importance of hydrodynamics and heat transfer in practice inspired continuing research for methods of efficient heat augmentation by the Lithuanian Energy Institute. The solution of this problem was directly linked with the determination of the reaction of flow in the boundary layer to the effect of various factors and heat transfer rate under given conditions. The investigated factors included elevated degree of turbulence of the external flow as well as strong acceleration and turbulization of flow near the wall by surface roughness. The material in this volume shows that it is possible to control the efficiency of turbulent transfer when the vortical structure of the turbulent flow is known.
Download or read book Application of Turbulence Modeling to Predict Surface Heat Transfer in Stagnation Flow Region of Circular Cylinder written by Chi-Rong Wang and published by . This book was released on 1987 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Navier Stokes Analysis of Turbine Blade Heat Transfer written by Robert J. Boyle and published by . This book was released on 1990 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Turbulent Flow and Heat Transfer on a Flat Plate at High Mach Numbers with Variable Fluid Properties written by R. G. Deissler and published by . This book was released on 1959 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multiple Scale kappa epsilon Turbulence Modeling of the Transitional Boundary Layer for Elevated Freestream Turbulence Levels written by and published by . This book was released on 1996 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
