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Variable Incidence Angle Film Cooling Experiments On A Scaled Up Turbine Airfoil Model
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Book Synopsis Variable Incidence Angle Film Cooling Experiments on a Scaled Up Turbine Airfoil Model by : Kyle Feliciano Chavez
Download or read book Variable Incidence Angle Film Cooling Experiments on a Scaled Up Turbine Airfoil Model written by Kyle Feliciano Chavez and published by . This book was released on 2016 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study focused on three main areas of research - the development of a new type of low-speed, closed-loop wind tunnel design to test at varying incidence angles, the investigation of film cooling for gas turbine components at varying incidence angles, and the analysis of the heat transfer and flow field predictive capability of RANS models. In order to develop the closed loop wind tunnel, a rigorous design and validation process was followed. This validated design is unique for low-speed closed-loop facilities. The development of this wind tunnel enabled measurements of adiabatic and overall effectiveness of two highly realistic airfoil models with shaped holes at varying incidence angles. This was accomplished through application of the appropriate aerodynamic and heat transfer scaling parameters for all measurements. Among other results, it was found that the shaped holes at the stagnation row of holes significantly enhanced film cooling effectiveness in the high curvature region of the showerhead depending on the incidence angle tested, and that the incidence angle effect persisted on the matched Biot number model. No previous studies had experimentally investigated the effects of incidence angle effects on overall effectiveness of a full-coverage airfoil. Furthermore, no previous studies had investigated the effect of shaped holes in the showerhead region of a realistic airfoil model such as the one used in this study. Finally, the computational predictive capability of various RANS turbulence models were analyzed by predicting the heat transfer coefficient of the model as well as the turbulence production and turning angle of a vertical array of rods used to generate turbulence in the tunnel. It was found that the computational predictions of leading-edge heat transfer were under-predicted due to the shape of the model leading edge. It was also found that the SST-Transition model appropriately predicted downstream turbulence and turning angle of the vertical rod array when compared to experimental results and empirical correlations in the literature. This is the first study to experimentally and computationally investigate the turning angle of a vertical grid array over a range of zero and non-zero inlet flow angles.
Book Synopsis Experimental Measurement of Overall Effectiveness and Internal Coolant Temperatures for a Film Cooled Gas Turbine Airfoil with Internal Impingement Cooling by : Randall Paul Williams
Download or read book Experimental Measurement of Overall Effectiveness and Internal Coolant Temperatures for a Film Cooled Gas Turbine Airfoil with Internal Impingement Cooling written by Randall Paul Williams and published by . This book was released on 2012 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: A scaled-up gas turbine vane model was constructed in such a way to achieve a Biot number (Bi) representative of an actual engine component, and experiments were performed to collect temperature data which may be used to validate computational fluid dynamics (CFD) codes used in the design of gas turbine cooling schemes. The physical model incorporated an internal impingement plate to provide cooling on the inner wall surface, and film cooling over the external surface was provided by a single row of holes located on the suction side of the vane. A single row of holes was chosen to simplify the operating condition and test geometry for the purpose of evaluating CFD predictions. Thermocouples were used to measure internal gas temperatures and internal surface temperatures over a range of coolant flow rates, while infra-red thermography was used to measure external surface temperatures. When Bi is matched to an actual engine component, these measured temperatures may be normalized relative to the coolant temperature and mainstream gas temperature to determine the overall cooling effectiveness, which will be representative of the real engine component. Measurements were made to evaluate the overall effectiveness resulting from internal impingement cooling alone, and then with both internal impingement cooling and external film cooling as the coolant flow rate was increased. As expected, with internal impingement cooling alone, both internal and external wall surfaces became colder as the coolant flow rate was increased. The addition of film cooling further increased the overall effectiveness, particularly at the lower and intermediate flow rates tested, but provided little benefit at the highest flow rates. An optimal jet momentum flux ratio of I=1.69 resulted in a peak overall effectiveness, although the film effectiveness was shown to be low under these conditions. The effect of increasing the coolant-to-mainstream density ratio was evaluated at one coolant flow rate and resulted in higher values of overall cooling effectiveness and normalized internal temperatures, throughout the model. Finally, a 1-dimensional heat transfer analysis was performed (using a resistance analogy) in which overall effectiveness with film cooling was predicted from measurements of film effectiveness and overall effectiveness without film cooling. This analysis tended to over-predict overall effectiveness, at the lowest values of the jet momentum flux ratio, while under-predicting it at the highest values.
Book Synopsis Procedure for Scaling of Experimental Turbine Vane Airfoil Temperatures from Low to High Gas Temperatures by : Herbert J. Gladden
Download or read book Procedure for Scaling of Experimental Turbine Vane Airfoil Temperatures from Low to High Gas Temperatures written by Herbert J. Gladden and published by . This book was released on 1971 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of procedure for scaling of experimental turbine vane airfoil temperatures from low to high gas temperatures.
Book Synopsis An Experimental Investigation of the Effects of Massive Film Cooling on the Aerodynamics of a Turbine Airfoil by : James Edward Hartsel
Download or read book An Experimental Investigation of the Effects of Massive Film Cooling on the Aerodynamics of a Turbine Airfoil written by James Edward Hartsel and published by . This book was released on 1970 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis An Experimental Investigation of the Effects of Massive Film Cooling on the Aerodynamics of a Turbine Airfoil by : James Edward Hartsel
Download or read book An Experimental Investigation of the Effects of Massive Film Cooling on the Aerodynamics of a Turbine Airfoil written by James Edward Hartsel and published by . This book was released on 1970 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Experimental Investigation of Overall Effectiveness and Coolant Jet Interactions on a Fully Cooled C3X Turbine Vane by : John W. McClintic
Download or read book Experimental Investigation of Overall Effectiveness and Coolant Jet Interactions on a Fully Cooled C3X Turbine Vane written by John W. McClintic and published by . This book was released on 2013 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study focused on experimentally measuring the performance of a fully cooled, scaled up C3X turbine vane. Experimental measurements focused on investigating row-to-row interactions of coolant jets and the contributions of external film cooling and internal impingement cooling to overall cooling effectiveness. Overall effectiveness was experimentally measured using a thermally scaled, matched Biot number vane model featuring a realistic internal impingement scheme and had normalized surface temperatures that were representative of those found on engine components. A geometrically identical vane was also constructed out of low conductivity polystyrene foam to measure the normalized adiabatic wall temperature, or adiabatic effectiveness of the film cooling configuration. The vanes featured a full coverage film-cooling scheme with a five-row showerhead and 13 total rows of holes containing 149 total coolant holes. This study was the first study to make highly detailed measurements of overall effectiveness on a fully-cooled vane model and expands on previous studies of adiabatic and overall effectiveness on the showerhead and single rows of holes on a matched Biot vane by considering a fully cooled configuration to determine if the results from these previous studies also hold for a fully cooled configuration. Additionally, velocity and thermal fields were measured just upstream of two different suction side rows of holes in order to study the effect of introducing upstream coolant injection. The effects of mainstream turbulence and span-wise location were examined and at the downstream row of holes, the contributions of different rows of holes to the approach flow were compared. This study was the first to measure mean and fluctuating velocity data on the suction side of a turbine vane with upstream coolant injection. Understanding the effects of how upstream injection affects the performance of downstream rows of holes is critical to understanding the film cooling performance on a fully cooled turbine airfoil.
Book Synopsis Prediction of Film Cooling on Gas Turbine Airfoils by :
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:
Book Synopsis Experimental and Computational Studies of Film Cooling with Compound Angle Injection by :
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.
Book Synopsis Experimental and Computational Investigation of Film Cooling on a Large Scale C3X Turbine Vane Including Conjugate Effects by : Thomas Earl Dyson
Download or read book Experimental and Computational Investigation of Film Cooling on a Large Scale C3X Turbine Vane Including Conjugate Effects written by Thomas Earl Dyson and published by . This book was released on 2012 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study focused on the improvement of film cooling for gas turbine vanes using both computational and experimental techniques. The experimental component used a matched Biot number model to measure scaled surface temperature (overall effectiveness) distributions representative of engine conditions for two new configurations. One configuration consisted of a single row of holes on the pressure surface while the other used numerous film cooling holes over the entire vane including a showerhead. Both configurations used internal impingement cooling representative of a 1st vane. Adiabatic effectiveness was also measured. No previous studies had shown the effect of injection on the mean and fluctuating velocity profiles for the suction surface, so measurements were made at two locations immediately upstream of film cooling holes from the fully cooled cooling configuration. Different blowing conditions were evaluated. Computational tools are increasingly important in the design of advanced gas turbine engines and validation of these tools is required prior to integration into the design process. Two film cooling configurations were simulated and compared to past experimental work. Data from matched Biot number experiments was used to validate the overall effectiveness from conjugate simulations in addition to adiabatic effectiveness. A simulation of a single row of cooling holes on the suction side also gave additional insight into the interaction of film cooling jets with the thermal boundary layer. A showerhead configuration was also simulated. The final portion of this study sought to evaluate the performance of six RANS models (standard, realizable, and renormalization group k-[epsilon]; standard k-[omega]; k-[omega] SST; and Transition SST) with respect to the prediction of thermal boundary layers. The turbulent Prandtl number was varied to test a simple method for improvement of the thermal boundary layer predictions.
Book Synopsis Airfoil, Platform, and Cooling Passage Measurements on a Rotating Transonic High-pressure Turbine by : Jeremy B. Nickol
Download or read book Airfoil, Platform, and Cooling Passage Measurements on a Rotating Transonic High-pressure Turbine written by Jeremy B. Nickol and published by . This book was released on 2016 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experiment was performed at The Ohio State University Gas Turbine Laboratory for a film-cooled high-pressure turbine stage operating at design-corrected conditions, with variable rotor and aft purge cooling flow rates. Several distinct experimental programs are combined into one experiment and their results are presented. Pressure and temperature measurements in the internal cooling passages that feed the airfoil film cooling are used as boundary conditions in a model that calculates cooling flow rates and blowing ratio out of each individual film cooling hole. The cooling holes on the suction side choke at even the lowest levels of film cooling, ejecting more than twice the coolant as the holes on the pressure side. However, the blowing ratios are very close due to the freestream massflux on the suction side also being almost twice as great. The highest local blowing ratios actually occur close to the airfoil stagnation point as a result of the low freestream massflux conditions. The choking of suction side cooling holes also results in the majority of any additional coolant added to the blade flowing out through the leading edge and pressure side rows.
Book Synopsis Film Cooling Effectiveness on a Turbine Vane in Transonic Conditions by : Isabella Gayoso
Download or read book Film Cooling Effectiveness on a Turbine Vane in Transonic Conditions written by Isabella Gayoso and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this experiment, measurements of the overall cooling effectiveness for a film cooled turbine vane airfoil in a high-speed cascade were obtained using infrared thermography. The vane used was the NASA C3X with impingement holes (showerhead cooling) and convective cooling holes on both the suction and pressure side. This work was done in the Mechanical Engineering Department's Experimental and Computational Convection Lab and used the high-speed cascade capability of the lab. The rationale for conducting this work was to obtain experimental data on film cooling effectiveness in a turbine vane in engine-like conditions at transonic speeds. Previous work has been done at subsonic speeds, but few pieces of literature examine this parameter at transonic speeds. The data can then be used to validate or compare to CFD models and to better understand what happens to the vane temperature distribution during engine operation. This understanding could inform the design of film cooling holes to reduce thermal strain "hot spots" which lead to failure of the vane. The results showed that trends for values of overall film effectiveness were as expected in this experiment, such as increases in blowing ratio correlating to increases in overall film effectiveness. However, the blowing ratios used in this study were not as high as values studied previously, indicating a need for more data on overall film effectiveness at transonic speeds.
Book Synopsis Active Control of Transverse Jets for Film Cooling Applications: A Limited Statement of Work by :
Download or read book Active Control of Transverse Jets for Film Cooling Applications: A Limited Statement of Work written by and published by . This book was released on 2006 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this project was to initiate investigation of film cooling flow control in order to improve its performance through active excitation of the film-cooling jet. A theoretical analysis was conducted and mechanisms that can play a defining role in film cooling control were identified on the basis of fundamental fluid-dynamics, prior experiments and preliminary numerical simulations. A cold flow wind-tunnel experiment incorporating a scaled-up, single film-cooling jet on a flat wall with a 90 deg injection angle was designed and built. The theoretical analysis was used to identify a window of essential flow-modulation parameters (frequency, duty cycle, mean blowing ratio, blowing ratio amplitude) within which film-cooling flow performance is expected to improve. A flow-pulsing system was designed, built and dynamically characterized. Both the wind tunnel boundary layer and jet exit flows were characterized using constant temperature anemometry. A series of preliminary experiments were conducted using reactive, Mie-scattering, laser-sheet visualizations for three mean blowing ratios with nearly zero low blowing ratio in the cycle, two duty cycles and four pulsing frequencies. The visualization results indicate that for the transverse jet with 90 deg injection angle, low frequency pulsations of the jet flow tend to increase the lateral coverage of the jet relative to the benchmark steady case without causing substantial lift-off at a blowing ratio of 0.5 and duty cycle of 50%. The observations are encouraging as to the feasibility of controlling the film cooling jet through mass flow pulsation and are consistent with predictions from fundamental analysis in terms of anticipated favorable operating conditions.
Book Synopsis Effects of Upstream Synfuel Deposition on Film Cooling Effectiveness and Convective Heat Transfer Coefficient Near Industrial Gas Turbine Film Cooling Holes by : Scott Dudley Lewis
Download or read book Effects of Upstream Synfuel Deposition on Film Cooling Effectiveness and Convective Heat Transfer Coefficient Near Industrial Gas Turbine Film Cooling Holes written by Scott Dudley Lewis and published by . This book was released on 2008 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: An experimental film cooling study was performed to understand heat transfer effects due to upstream synfuel deposition. A scaled up model incorporating actual synfuel deposition topography was used. The model contained six cylindrical holes inclined at 300. A flat model with the same film cooling hole geometry was used for comparison. An infrared camera was used to obtain both the film cooling effectiveness from a steady state test and heat transfer coefficient from a transient test. The roughness model had deposition valleys along the centerline of the holes, which caused the flow to accelerate around the peaks and helped to keep the coolant jet down on the surface. This flow acceleration caused large film cooling effectiveness improvements for the 1 and 1.5 blowing ratio cases. The heat transfer coefficient showed both cooling benefits as well as cooling losses due to deposit roughness. The roughness model showed no kidney vortices as opposed to the flat model, which produced a beneficial localized reduction in heat transfer coefficient around the film cooling holes. Although a sharp detrimental rise in heat transfer coefficient occurred on the rough model for the 1.5 blowing ratio case. The heat flux ratio shows the overall cooling effect and a substantial cooling benefit compared to the flat model occurred at blowing ratios of 1 and 1.5. It is concluded that the film cooling effects of upstream deposition on actual turbine blades can be highly beneficial.
Book Synopsis Sweeping Jet Film Cooling by : Mohammad Arif Hossain
Download or read book Sweeping Jet Film Cooling written by Mohammad Arif Hossain and published by . This book was released on 2020 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas turbine is an integrated part of modern aviation and power generation industry. The thermal efficiency of a gas turbine strongly depends on the turbine inlet temperature (TIT), and the turbine designers are continuously pushing the TIT to a higher value. Due to the increased freedom in additive manufacturing, the complex internal and external geometries of the turbine blade can be leveraged to utilize innovative cooling designs to address some of the shortcomings of current cooling technologies. The sweeping jet film cooling has shown some promise to be an effective method of cooling where the coolant can be brought very close to the blade surface due to its sweeping nature. A series of experiments were performed using a row of fluidic oscillators on a flat plate. Adiabatic cooling effectiveness, convective heat transfer coefficient, thermal field, and discharge coefficient were measured over a range of blowing ratios and freestream turbulence. Results were compared with a conventional shaped hole (777-hole), and the sweeping jet hole shows improved cooling performance in the lateral direction. Numerical simulation also confirmed that the sweeping jet creates two alternating vortices that do not have mutual interaction in time. When the jet sweeps to one side of the hole exit, it acts as a vortex generator as it interacts with the mainstream ow. This prevents the formation of the counter-rotating vortex pair (CRVP) and allows the coolant to spread in the lateral direction. The results obtained from the low speed at plate tests were utilized to design the sweeping jet film cooling hole for more representative turbine vane geometry. Experiments were performed in a low-speed linear cascade facility. Results showed that the sweeping jet hole has higher cooling effectiveness in the near hole region compared to the shaped hole at high blowing ratios. Next, a detailed experimental investigation of sweeping jet film cooling on the suction surface of a near engine scale transonic nozzle guide vane at an engine relevant Mach number (Ma = 0.8) and Reynolds number (Re = 1x10e6) to determine the effect of compressibility. The heat transfer measurements were conducted with a transient IR method, and the convective heat transfer coefficient (HTC) and adiabatic film cooling effectiveness were estimated using a dual linear regression technique (DLRT). Aerodynamic loss measurements were also performed at an exit plane downstream of the vane cascade. Finally, a comprehensive design integration of sweeping jet film hole was carried out in a Direct Metal Laser Sintering (DMLS) enabled engine scale nozzle guide vane and experimental investigation of overall cooling effectiveness at engine relevant temperature conditions were assessed. The systematic evolution of a sweeping jet film cooling hole design from a large scale flat plate to an engine scale nozzle guide vane has been presented.
Book Synopsis Scientific and Technical Aerospace Reports by :
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 1134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Experimental Study on Film Cooling of Gas Turbine Airfoils Using Shaped Holes by : Hans Claudius Reiss
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:
Book Synopsis Evaluation of Film Cooling Superposition Method on the Suction Side of a Blade Model by : Christopher Yoon
Download or read book Evaluation of Film Cooling Superposition Method on the Suction Side of a Blade Model written by Christopher Yoon and published by . This book was released on 2018 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Film cooling is often used for turbine airfoil cooling, and there are numerous studies of the performance of a single row of holes. Typically, blades and vanes in gas turbine engines have multiple rows of holes that interact. Consequently, there is a need to develop techniques to predict film cooling performance with multiple rows of holes. One of the method is to superposition single row cooling effectiveness to predict combined effectiveness. Although there have been many studies of superposition techniques with multiple rows of cylindrical holes, there have been very few in which shaped holes were used with a typical turbine airfoil model. In this study, film effectiveness was measured on the suction side of a turbine blade model using two rows of 7-7-7 shaped holes, with pitch to diameter ratio of 6, and the two rows were more than 40 diameters apart. Measurements were made with each row operating independently, which provided the experimental data for superposition predictions. These predictions were evaluated with effectiveness measurements with both rows operational. For these combined row tests, two different upstream blowing ratios and a wide range of downstream blowing ratios were selected. The superposition predictions were reasonably accurate when the upstream blowing ratio was high with a corresponding smaller film effectiveness downstream (due to jet separation). However, when the upstream coolant holes were operated at optimum blowing ratio with maximum film effectiveness downstream, the superposition analysis predicted film effectiveness levels slightly lower than actual levels. These results indicate that there was an interaction between jets that resulted in higher film effectiveness than what the superposition method had predicted
