Download or read book Aerodynamic Loss Models and Multi dimensional Prediction of Discrete Hole Film Cooling on Gas Turbine Blades written by İlker Topçuoğlu and published by . This book was released on 2013 with total page 145 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 NASA Scientific and Technical Publications written by and published by . This book was released on 1987 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Three Dimensional Aero Thermal Optimization of Film Cooling in a High Pressure Turbine written by Carole El Ayoubi and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Film Cooling and Aerodynamic Loss in a Gas Turbine Cascade written by Sadasuke Ito and published by . This book was released on 1976 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Heat Transfer in Gas Turbines written by Bengt Sundén and published by Witpress. This book was released on 2001 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: This title presents and reflects current active research on various heat transfer topics and related phenomena in gas turbine systems. It begins with a general introduction to gas turbine heat transfer, before moving on to specific areas.
Download or read book Gas Turbine Blade Cooling written by Chaitanya D Ghodke and published by SAE International. This book was released on 2018-12-10 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas turbines play an extremely important role in fulfilling a variety of power needs and are mainly used for power generation and propulsion applications. The performance and efficiency of gas turbine engines are to a large extent dependent on turbine rotor inlet temperatures: typically, the hotter the better. In gas turbines, the combustion temperature and the fuel efficiency are limited by the heat transfer properties of the turbine blades. However, in pushing the limits of hot gas temperatures while preventing the melting of blade components in high-pressure turbines, the use of effective cooling technologies is critical. Increasing the turbine inlet temperature also increases heat transferred to the turbine blade, and it is possible that the operating temperature could reach far above permissible metal temperature. In such cases, insufficient cooling of turbine blades results in excessive thermal stress on the blades causing premature blade failure. This may bring hazards to the engine's safe operation. Gas Turbine Blade Cooling, edited by Dr. Chaitanya D. Ghodke, offers 10 handpicked SAE International's technical papers, which identify key aspects of turbine blade cooling and help readers understand how this process can improve the performance of turbine hardware.
Download or read book Paper written by and published by . This book was released on 2001 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Scientific and Technical Publications written by and published by . This book was released on 1987 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Prediction of Film Cooling on Gas Turbine Airfoils written by and published by . This book was released on 1994 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Film Cooling and End Wall Heat Transfer in Small Turbine Blade Passages written by and published by . This book was released on 1978 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two topics have been studied related to the cooling of the end wall of a turbine passage. The first concerns the development of a method for measuring the adiabatic wall effectiveness and heat transfer coefficient of a film cooling system for protecting a surface from high heating derived from a hot compressible flow. The second concerns the measurement of the heat transfer rate distribution to a turbine cascade end wall in order to choose an appropriate film cooling system. These are related to providing the background to the final phase of the study in which the effectiveness of a film cooling system to cool a turbine end wall will be made combined with the measurement of the aerodynamic losses incurred by such a system. (Author).
Download or read book NASA SP written by and published by . This book was released on 1962 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Curvature Effects on the Heat Transfer Performance of Three Dimensional Film Cooling of Gas Turbine Blades written by E. R. G. Eckert and published by . This book was released on 1982 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Film cooling is used extensively for the blades of high-performance, high-temperature gas turbines, especially for aircraft turbines. In this method, a film of coolant is injected into the boundary layer covering the skin of the blades and creating a cool layer which separates the blade surface from the hot gas stream and, in this way, reduces the blade temperature. For best performance the coolant should be injected through a slot or a strip of porous material. This, however, is not possible for turbine blades because of strength considerations, and the coolant is injected through one or several rows of holes. For aircraft gas turbines, air is used as a coolant. The present investigation, therefore, is concerned with the cooling performance of film cooling when cooling air is injected into the boundary through one or two rows of holes. A standard configuration of the coolant holes is used because it has been used in previous investigations and because configurations in actual turbine blades are close to it. The cooling holes are arranged at a distance apart equal to three times the hole diameter. For injection through two rows of holes, the two rows are staggered and the centers of the holes are on the corners of equilateral triangles. The channels which end at the blade skin in the cooling holes are inclined by an angle of 35 deg against the skin surface in the downstream direction.
Download or read book Experimental Study of Gas Turbine Blade Film Cooling and Heat Transfer written by Diganta P. Narzary and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern gas turbine engines require higher turbine-entry gas temperature to improve their thermal efficiency and thereby their performance. A major accompanying concern is the heat-up of the turbine components which are already subject to high thermal and mechanical stresses. This heat-up can be reduced by: (i) applying thermal barrier coating (TBC) on the surface, and (ii) providing coolant to the surface by injecting secondary air discharged from the compressor. However, as the bleeding off of compressor discharge air exacts a penalty on engine performance, the cooling functions must be accomplished with the smallest possible secondary air injection. This necessitates a detailed and systematic study of the various flow and geometrical parameters that may have a bearing on the cooling pattern. In the present study, experiments were performed in three regions of a non-rotating gas turbine blade cascade: blade platform, blade span, and blade tip. The blade platform and blade span studies were carried out on a high pressure turbine rotor blade cascade in medium flow conditions. Film-cooling effectiveness or degree of cooling was assessed in terms of cooling hole geometry, blowing ratio, freestream turbulence, coolant-to-mainstream density ratio, purge flow rate, upstream vortex for blade platform cooling and blowing ratio, and upstream vortex for blade span cooling. The blade tip study was performed in a blow-down flow loop in a transonic flow environment. The degree of cooling was assessed in terms of blowing ratio and tip clearance. Limited heat transfer coefficient measurements were also carried out. Mainstream pressure loss was also measured for blade platform and blade tip film-cooling with the help of pitot-static probes. The pressure sensitive paint (PSP) and temperature sensitive paint (TSP) techniques were used for measuring film-cooling effectiveness whereas for heat transfer coefficient measurement, temperature sensitive paint (TSP) technique was employed. Results indicated that the blade platform cooling requires a combination of upstream purge flow and downstream discrete film-cooling holes to cool the entire platform. The shaped cooling holes provided wider film coverage and higher film-cooling effectiveness than the cylindrical holes while also creating lesser mainstream pressure losses. Higher coolant-to-mainstream density ratio resulted in higher effectiveness levels from the cooling holes. On the blade span, at any given blowing ratio, the suction side showed better coolant coverage than the pressure side even though the former had two fewer rows of holes. Film-cooling effectiveness increased with blowing ratio on both sides of the blade. Whereas the pressure side effectiveness continued to increase with blowing ratio, the increase in suction side effectiveness slowed down at higher blowing ratios (M=0.9 and 1.2). Upstream wake had a detrimental effect on film coverage. 0% and 25% wake phase positions significantly decreased film-cooling effectiveness magnitude. Comparison between the compound shaped hole and the compound cylindrical hole design showed higher effectiveness values for shaped holes on the suction side. The cylindrical holes performed marginally better in the curved portion of the pressure side. Finally, the concept tip proved to be better than the baseline tip in terms of reducing mainstream flow leakage and mainstream pressure loss. The film-cooling effectiveness on the concept blade increased with increasing blowing ratio and tip gap. However, the film-coverage on the leading tip portion was almost negligible.
Download or read book Prediction of Heat Transfer Characteristics for Discrete Hole Film Cooling for Turbine Blade Applications written by Daneshmund K. Tafti and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
