Download or read book Numerical and Experimental Study of Trenched Hole Film Cooling with Forward and Backward Injection Angles written by Kunal M. Gharat and published by . This book was released on 2013 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical and Experimental Study of Film Cooling with Backward Injection Angle written by Ganesh Subbuswamy and published by . This book was released on 2012 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Film Cooling with Ejection from a Row of Inclined Circular Holes written by Christian Liess and published by . This book was released on 1973 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Computational Studies of Film Cooling with Compound Angle Injection written by and published by . This book was released on 1995 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: The thermal efficiency of gas turbine systems depends largely on the turbine inlet temperature. Recent decades have seen a steady rise in the inlet temperature and a resulting reduction in fuel consumption. At the same time, it has been necessary to employ intensive cooling of the hot components. Among various cooling methods, film cooling has become a standard method for cooling of the turbine airfoils and combustion chamber walls. The University of Minnesota program is a combined experimental and computational study of various film-cooling configurations. Whereas a large number of parameters influence film cooling processes, this research focuses on compound angle injection through a single row and through two rows of holes. Later work will investigate the values of contoured hole designs. An appreciation of the advantages of compound angle injection has risen recently with the demand for more effective cooling and with improved understanding of the flow; this project should continue to further this understanding. Approaches being applied include: (1) a new measurement system that extends the mass/heat transfer analogy to obtain both local film cooling and local mass (heat) transfer results in a single system, (2) direct measurement of three-dimensional turbulent transport in a highly-disturbed flow, (3) the use of compound angle and shaped holes to optimize film cooling performance, and (4) an exploration of anisotropy corrections to turbulence modeling of film cooling jets.
Download or read book A Numerical Study of Discrete hole Film Cooling written by Mulugeta K. Berhe and published by . This book was released on 1997 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental and Numerical Study of Heat Transfer Augmentation Near the Entrance to a Film Cooling Hole written by Gerard Scheepers and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Developments regarding internal cooling techniques have allowed the operation of modern gas turbine engines at turbine inlet temperatures which exceed the metallurgical capability of the turbine blade. This has allowed the operation of engines at a higher thermal efficiency and lower specific fuel consumption. Modern turbine blade-cooling techniques rely on external film cooling to protect the outer surface of the blade from the hot gas path and internal cooling to remove thermal energy from the blade. Optimization of coolant performance and blade-life estimation require knowledge regarding the influence of cooling application on the blade inner and outer surface heat transfer. The following study describes a combined experimental and computational study of heat transfer augmentation near the entrance to a film-cooling hole. Steady-state heat transfer results were acquired by using a transient measurement technique in an 80 x actual rectangular channel, representing an internal cooling channel of a turbine blade. Platinum thin-film gauges were used to measure the inner surface heat transfer augmentation as a result of thermal boundary layer renewal and impingement near the entrance of a film-cooling hole. Measurements were taken at various suction ratios, extraction angles and wall temperature ratios with a main duct Reynolds number of 25? 103. A numerical technique, based on the resolution of the unsteady conduction equation, using a Crank-Nicholson scheme, was used to obtain the surface heat flux from the measured surface temperature history. Computational data was generated with the use of a commercial CFD solver.
Download or read book Experimental and Numerical Study of Endwall Film Cooling written by Srikrishna Mahadevan and published by . This book was released on 2015 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research work investigates the thermal performance of a film-cooled gas turbine endwall under two different mainstream flow conditions. In the first part of the research investigation, the effect of unsteady passing wakes on a film-cooled pitchwise-curved surface (representing an endwall without airfoils) was experimentally studied for heat transfer characteristics on a time-averaged basis. The temperature sensitive paint technique was used to obtain the local temperatures on the test surface. The required heat flux input was provided using foil heaters. Discrete film injection was implemented on the test surface using cylindrical holes with a streamwise inclination angle of 35° and no compound angle relative to the mean approach velocity vector. The passing wakes increased the heat transfer coefficients at both the wake passing frequencies that were experimented. Due to the increasing film cooling jet turbulence and strong jet-mainstream interaction at higher blowing ratios, the heat transfer coefficients were amplified. A combination of film injection and unsteady passing wakes resulted in a maximum pitch-averaged and centerline heat transfer augmentation of [approximately equal to] 28% and 31.7% relative to the no wake and no film injection case.
Download or read book Velocity Distributions and Heat Transfer with Film Cooling Near a Single Angled Spanwise continuous Injection Slot a Numerical and Experimental Study written by Herbert Jackson Carper and published by . This book was released on 1969 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical and Experimental Study of Flow and Heat Transfer from a Flush Inclined Film Cooling Slot microform written by David M. (David Murray) Sinitsin and published by National Library of Canada. This book was released on 1988 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Study of Heat Transfer Inside Film Cooling Hole Models written by Faysal Baty and published by . This book was released on 1993 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Film Cooling with Forward and Backward Injection for Cylindrical and Fan shaped Holes Using PSP Measurement Technique written by Andrew F. Chen and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A systematic study was performed to investigate the combined effects of hole geometry, blowing ratio, density ratio and free-stream turbulence intensity on flat plate film cooling with forward and backward injection. Detailed film cooling effectiveness distributions were obtained using the steady state pressure sensitive paint (PSP) technique. Four common film-hole geometries with forward injection were used in this study: simple angled cylindrical holes and fan-shaped holes, and compound angled (ß= 45°) cylindrical holes and fan-shaped holes. Additional four film-hole geometries with backward injection were tested by reversing the injection direction from forward to backward to the mainstream. There are seven holes in a row on each plate and each hole is 4 mm in diameter. The blowing ratio effect is studied at 10 different blowing ratios ranging from M = 0.3 to M = 2.0. The coolant to main stream density ratio (DR) effect is studied by using foreign gases with DR = 1 (N2), 1.5 (CO2), and 2 (15% SF6 + 85% Ar). The free stream turbulence intensity effect is tested at 0.5% and 6%. The results of the parametric effects to the film cooling effectiveness with forward injection agreed with open literatures. In general, the results show the film cooling effectiveness with backward injection is greatly reduced for shaped holes as compared with the forward injection. However, significant improvements can be seen in simple angled cylindrical hole at higher blowing ratios. Backward injection also shows improvements at near film-hole regions for compound angled cylindrical holes at higher blowing ratios. Comparison was made between the experimental data and empirical correlation for simple angled fan-shaped holes. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151849
Download or read book Computational and Experimental Study of Film Cooling Performance Including Shallow Trench Configurations written by Katharine Lee Harrison and published by . This book was released on 2006 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Film cooling computations and experiments were performed to study heat transfer and adiabatic effectiveness for several geometries. Various assumptions commonly made in film cooling experiments were computationally simulated to test the validity of using these assumptions to predict the heat flux into conducting walls. The validity of these assumptions was examined via computational simulations of film cooling on adiabatic, heated, and conducting flat plates using the commercial code FLUENT. The assumptions were found to be reasonable overall, but certain regions in the domain suffered from poor predictions. Film cooling adiabatic effectiveness and heat transfer coefficients for axial holes embedded in a 1 [hole diameter] transverse trench on the suction side of a simulated turbine vane were experimentally investigated as well to determine the net heat flux reduction. Heat transfer coefficients were determined with and without upstream heating both with and without a tripped boundary layer approach flow. The net heat flux reduction for the trench was found to be much higher than for the baseline row of holes. Two transverse trench geometries and a baseline row of holes geometry were also simulated using FLUENT and the results were compared to experiments by Waye and Bogard (2006). Trends between simulated trench configurations and baseline cylindrical holes without a trench were found to be largely in agreement with experimental trends, suggesting that FLUENT can be used as a tool for studying new trench configurations.
Download or read book Effect on Gaseous Film Cooling of Coolant Injection Through Angled Slots and Normal Holes written by S. Stephen Papell and published by . This book was released on 1960 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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:
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 Streakline flow visualization of discrete hole film cooling with normal slanted and compound angle injection written by Raymond S. Colladay and published by . This book was released on 1976 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Study on Film Cooling of Gas Turbine Airfoils Using Shaped Holes written by Hans Claudius Reiss and published by . This book was released on 2000 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
