Download or read book Prediction of Flow and Heat Transfer Inside Turbine Blades Using EARSM kappa epsilon and kappa omega Turbulence Models written by and published by . This book was released on 1999 with total page 119 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 Prediction of Relaminarization Effects on Turbine Blade Heat Transfer written by and published by . This book was released on 2001 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Turbine Blade Heat Transfer Prediction in Flow Transition Using K w Two equation Model written by R.-J. Yang and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Two dimensional Navier Stokes Heat Transfer Analysis for Rough Turbine Blades written by and published by . This book was released on 1991 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A quasi-three-dimensional thin-layer Navier-Stokes analysis was used to predict heat transfer to rough surfaces. Comparisons are made between predicted and experimental heat transfer for turbine blades and flat plates of known roughness. The effect of surface Toughness on heat transfer was modeled using a mixing length approach. The effect of near-wall grid spacing and convergence criteria on the accuracy of the heat transfer predictions are examined. An eddy viscosity mixing length model having an inner and outer layer was used. A discussion of the appropriate model for the crossover between the inner and outer layers is included. The analytic results are compared with experimental data for both flat plates and turbine blade geometries. Comparisons between predicted and experimental heat transfer showed that a modeling roughness effects using a modified mixing length approach results in good predictions of the trends in heat transfer due to roughness. Turbine, Heat transfer, Rough surface.

Download or read book Prediction of Relaminarization Effects on Turbine Blade Heat Transfer written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-19 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: An approach to predicting turbine blade heat transfer when turbulent flow relaminarizes due to strong favorable pressure gradients is described. Relaminarization is more likely to occur on the pressure side of a rotor blade. While stators also have strong favorable pressure gradients, the pressure surface is less likely to become turbulent at low to moderate Reynolds numbers. Accounting for the effects of relaminarization for blade heat transfer can substantially reduce the predicted rotor surface heat transfer. This in turn can lead to reduced rotor cooling requirements. Two-dimensional midspan Navier-Stokes analyses were done for each of eighteen test cases using eleven different turbulence models. Results showed that including relaminarization effects generally improved the agreement with experimental data. The results of this work indicate that relatively small changes in rotor shape can be utilized to extend the likelihood of relaminarization to high Reynolds numbers. Predictions showing how rotor blade heat transfer at a high Reynolds number can be reduced through relaminarization are given. Boyle, R. J. and Giel, P. W. Glenn Research Center NASA/TM-2001-210978, NAS 1.15:210978, E-12832, Rept-2001-GT-0162

Download or read book Comparison of Two equation Turbulence Models for Prediction of Heat Transfer on Film cooled Turbine Blades written by Vijay K. Garg and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine & Aeroengine Congress & Exhibition, Orlando, FL, Jun 2-Jun 5, 1997.

Download or read book Blade Heat Transfer Measurements and Prediction in a Transonic Turbine Cascade written by and published by . This book was released on 1999 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Prediction of Turbine Blade Heat Transfer with a Turbulence Model Including Surface Curvature Effects written by Fernando M. Ferreira and published by . This book was released on 1993 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three dimensional Navier Stokes Heat Transfer Predictions for Turbine Blade Rows written by Robert J. Boyle and published by . This book was released on 1992 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Heat Transfer Measurements and Predictions on a Power Generation Gas Turbine Blade written by and published by . This book was released on 2000 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed heat transfer measurements and predictions are given for a power generation turbine rotor with 129 deg of nominal turning and an axial chord of 137 mm. Data were obtained for a set of four exit Reynolds numbers comprised of the design point of 628,000, -20%, +20%, and +40%. Three ideal exit pressure ratios were examined including the design point of 1.378, -10%, and +10%. Inlet incidence angles of 0 deg and +/-2 deg were also examined. Measurements were made in a linear cascade with highly three-dimensional blade passage flows that resulted from the high flow turning and thick inlet boundary layers. Inlet turbulence was generated with a blown square bar grid. The purpose of the work is the extension of three-dimensional predictive modeling capability for airfoil external heat transfer to engine specific conditions including blade shape, Reynolds numbers, and Mach numbers. Data were obtained by a steady-state technique using a thin-foil heater wrapped around a low thermal conductivity blade. Surface temperatures were measured using calibrated liquid crystals. The results show the effects of strong secondary vortical flows, laminar-to-turbulent transition, and also show good detail in the stagnation region.

Download or read book Prediction of Turbine Blade Heat Transfer by a Two equation Turbulence Model written by Le Trong Tran and published by . This book was released on 1987 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Inlet Turbulence and Rotor stator Interactions on the Aerodynamics and Heat Transfer of a Large scale Rotating Turbine Model Volume 1 written by Robert P. Dring and published by . This book was released on 1987 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Procedure for Calculating Turbine Blade Temperatures and Comparison of Calculated with Observed Values for Two Stationary Air cooled Blades written by W. Byron Brown and published by . This book was released on 1952 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Local and average blade temperatures were calculated for two stationary air-cooled turbine blades with 10 tubes and 13 fins forming the internal heat-transfer surfaces. These temperatures were calculated using previously published NACA temperature-distribution equations and the most recent theories for determining heat-transfer coefficients, including for the first time the allowance for effects of variable wall temperature on gas-to-blade heat-transfer coefficients at the leading and trailing sections of turbine blades. Comparison of calculated and experimental blade temperatures, for gas temperatures of 300° and 1000°F, resulted in good agreement.

Download or read book Experimental Investigation of the Heat transfer Characteristics of an Air cooled Sintered Porous Turbine Blade written by Louis J. Schafer (Jr.) and published by . This book was released on 1952 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurements and Computational Analysis of Heat Transfer and Flow in a Simulated Turbine Blade Internal Cooling Passage written by Louis M. Russell and published by . This book was released on 1993 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Turbine Blade Relative Cooling Flow Factor Used in the Subroutine Coolit Based on Film Cooling Correlations written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2019-01-14 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat transfer correlations of data on flat plates are used to explore the parameters in the Coolit program used for calculating the quantity of cooling air for controlling turbine blade temperature. Correlations for both convection and film cooling are explored for their relevance to predicting blade temperature as a function of a total cooling flow which is split between external film and internal convection flows. Similar trends to those in Coolit are predicted as a function of the percent of the total cooling flow that is in the film. The exceptions are that no film or 100 percent convection is predicted to not be able to control blade temperature, while leaving less than 25 percent of the cooling flow in the convection path results in nearing a limit on convection cooling as predicted by a thermal effectiveness parameter not presently used in Coolit. Schneider, Steven J. Glenn Research Center WBS 475122.02.03.02.02