Download or read book Comparison of Steady and Time accurate Predictions with Experiment for the Aerodynamics of a Fully Cooled Single stage High pressure Turbine written by Suzanne A. Southworth and published by . This book was released on 2006 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The aerodynamics of a fully cooled single stage high-pressure turbine operating at design corrected conditions has been the subject of a thorough study involving experimental and computational work. The experimental configuration included a fully cooled, full-stage high-pressure turbine stage operating at design corrected conditions of corrected speed, flow function, and stage pressure ratio. The data reported in this thesis were obtained for a relatively low vane inlet Reynolds number condition in order to test the limits of the experimental system. The vanes and blades of the turbine and the stationary shroud immediately above the blade were instrumented. The vanes were instrumented with heat-flux gauges and pressure transducers at one span wise external location and two internal locations. The blades were instrumented with heat-flux gauges and pressure transducers at three different span wise external locations to provide external heat-flux and surface-pressure distributions, and internally with pressure transducers and miniature thermocouples to provide pressure and temperature histories within the airfoil cooling cavities. The stationary shroud was instrumented with heat-flux gauges and pressure transducers at several axial chord locations. Kulite pressure transducers were used to obtain all of the pressure data and double-sided Kapton heatflux gages were used for the heat transfer measurements on the vanes and blades while button-type gauges were used in the stationary shroud. Aerodynamic predictions were obtained using the computational fluid dynamics (CFD) codes Numeca's FINE/Turbo and Mississippi State University (MSU) Turbo, but for both calculations the addition of the film cooling gas was ignored. Further calculations are in progress that do include the film cooling, but results from those calculations are not reported herein. Both of these codes are 3D viscous codes, but FINE/Turbo was used to obtain both steady and time-accurate results while MSUTURBO was used to obtain only time-accurate results. Both FINE/Turbo and MSU Turbo utilize phase lagged boundary conditions to simplify the model and significantly reduce computing time and resources. The unsteady loadings, as predicted and measured, are compared for the blade, vane, and shroud as time-averaged, time series, and power series data. The steady CFD prediction was also obtained so as to provide the initial boundary conditions for the unsteady prediction. Therefore, comparisons of the steady CFD predictions and the time- averaged data were also made. The blade included a recessed tip geometry, which was included in the CFD model, and the CFD analysis also investigated different tip/shroud clearances to investigate the influence of the tip cap height on the downstream flow field. The analysis shows that both the steady state and time-accurate pressure predictions compare quite well with the experimental results. The steady and timeaveraged vane predictions are closer to the data than the steady prediction for the blade, but that is to be expected with the unsteady nature of the flow over the blade. The timeaccurate prediction for the blade is in very good agreement with the experimental results. The FINE/Turbo heat transfer predictions (MSU Turbo doesn't do heat-transfer predictions at the present time) are not showing similar trends as the data but this is likely due to the fact that the film cooling was ignored and due to the grid density utilized for these calculations. Since this work is meant to be a true prediction without any model optimization, it is interesting to see where the CFD produces the best results and where it has the most difficulty. It is also important to keep in mind that this work compares an uncooled CFD prediction to data obtained for a fully cooled turbine stage. This is the first time such data has been available and the uncooled CFD predictions will lend insight into the importance of cooling modeling, which has yet to become developed to a point that it is widely used in CFD predictions. Overall, the comparisons made here demonstrate the ability of two different CFD codes to successfully capture the unsteady flow physics on the blade surface and in the blade tip/stationary shroud region.

Download or read book Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Steady and Harmonic Predictions for a Single stage Fully Cooled Turbine written by Mark Brody Wishart and published by . This book was released on 2010 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: Several modeling details are considered when performing these computations; attention to detail is shown to be especially important when attempting to acquire heat-transfer predictions. A y+ sensitivity study shows that surface static-pressure predictions are relatively insensitive to y+, but heat-transfer predictions are very sensitive to changes in the y+ range. All computations utilize y+ values in the range of 1 to 10, which is required by the Spalart-Allmaras turbulence model. This study uses the distributed source term injection approach to model film cooling.

Download or read book Time accurate Predictions for the Aerodynamics of A 1 and 1 2 Stage HP Transonic Turbine written by Eric A. Crosh and published by . This book was released on 2008 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Multi-frequency signals exist in turbomachinery due to a variety of reasons from different periodicities of vanes and blades to manufacturing tolerances. The effects of different frequencies can vary depending on a number of variables, such as which frequency dominates and the associated amplitude. The ability of CFD to predict the flow physics for a specific case is examined with the intent to compare to the predictions with previously available measurements.

Download or read book ASME Technical Papers written by and published by . This book was released on 1998 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Heat Transfer in the Blade Row and Tip Region of a Modern Transonic High Pressure Turbine with and Without Forward Cavity Purge Flow written by Stephen M. Molter and published by . This book was released on 2006 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: A full scale rotating turbine rig operated at design corrected conditions has been used to study the heat transfer mechanisms affecting the flowpath surfaces within a modem single stage high-pressure (HP) turbine. The experimental rig was first run completely un-cooled and is currently being re-constructed to accommodate HP vane airfoil and endwall cooling and inner-stage cavity purge flow injection. Heat flux and pressure data were measured for both a flat and recessed, or squealer, HP blade tip and the stationary shroud above. The measurements indicate that the recessed tip, used in the majority of modem turbines to minimize blade damage from rubs, increases the blade heat load overall, and creates several hot spots on the floor of the recess for an un-cooled airfoil. The tip data also showed there were significant unsteady variations in the heat load at the vane passing frequency. Steady state CFD calculations were completed for both flat and squealer tip configurations to examine if the analysis could capture the details that were measured. The CFD, while not capable of estimating the unsteady heat load component and generally over predicting the overall heat flux by 10-25%, did capture the measured heat flux trends in the recessed tip. The steady state CFD prediction did show good agreement with the time-accurate data along the stationary shroud. These results show that steady-state CFD analysis can be useful in predicting the complex flow field and heat load distribution in turbine blade tips to help guide future blade designs. Pre-test CFD predictions were also performed for the upcoming series of experiments that include replacing the un-cooled vane row with a fully cooled HP vane row and the introduction of HP blade forward cavity purge flow, while leaving the HP blade un-cooled. The focus of the steady state predictions for the HP blade row was two fold; to assist in guiding the placement of new heat flux and pressure instrumentation and to study the cold flow migration through the HP blade row. Adiabatic wall temperature and Nusselt number predictions along the blade surface showed large radial, or spanwise, gradients, mostly along the suction side of the blade. Surface visualization on the suction side of the blade revealed two bands of cooler regions located at the upper and lower spans, with the middle spans being hotter, comparable to the pressure side. The lower band of cool flow is a result of the forward cavity purge flow, which mostly migrates to the suction side of the blade passage. By the trailing edge of the blade the purge flow has migrated upwards to an extent of approximately 20% of the blade span surface. The upper band of cool flow is a result of the cooling flow from the HP vane outer endwall. Blade tip secondary flows and the tip leakage vortex act to entrain this cool flow into the tip gap, resulting in its migration to the suction side of the blade. Due to a downward migration of the tip vortex along the suction side through the blade row, this cool band along the airfoil surface affects the upper 20% of the blade span. Results from the pre-test CFD predictions were also analyzed along the blade platform and rim seal surfaces. Migration of the forward cavity purge flow towards the suction side increases the Nusselt number along the rim seal and platform in these areas. Adiabatic wall temperatures on the platform surface were reasonably constant and lower than those on the blade surface, an effect of a portion of the purge flow being entrained into the platform boundary layer. Pressure asymmetries along the rim seal created circumferential variations in the local purge mass flow rates, with the leading edge of blade being the location of highest pressure and thus lower purge injection. Results also indicate the possibility of hot gas ingestion into the upper region of the rim seal at the leading edge. When data is available from the updated turbine rig, the comparisons will help to further validate this code as a useful design tool.

Download or read book Paper written by and published by . This book was released on 1998 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Steady Heat Transfer Predictions for a Highly Loaded Single Stage Turbine with Flat Tip written by Daniel H. Luk and published by . This book was released on 2008 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This thesis presents steady computational predictions for a single stage (2-blade-row), highly loaded, turbine. Computational predictions and experimental measurements of heat flux are compared for both the stator vane and the rotor blade with a flat tip. Comparisons for both blade rows are presented at three different spanwise locations as well as on the hub and casing endwalls and rotor tip. The experimental measurements were taken from earlier experiments conducted at the Ohio State University Gas Turbine Laboratory Test Facility. The computational predictions were achieved using TURBO. This CFD code is a 3D, Reynolds-Averaged Navier-Stokes (RANS), computational fluid dynamics code capable of handling unsteady flows. The CFD solutions were steady and computed as two separate computations. First, the stator vane simulation was performed using known inlet and exit boundary conditions. Then, inlet boundary conditions for the rotor blade simulation were taken from radial exit profiles of the steady stator vane solution and exit boundary conditions for the rotor blade was taken from previous CFD solutions which involved a 3-blade row simulation. The CFD heat transfer predictions compared well with the stator vane experimental values. The CFD heat flux prediction comparisons with the experimental measurements for the rotor blade were only fair. The largest percent error between the computation and the experimental measurements was 25%. The predictions for the hub of the rotor blade had good agreement with the experimental data. Most of the predictions were within the tight scatter of experimental data. The CFD heat transfer prediction for the rotor tip had good agreement with previous computational predictions but only fair agreement with experimental data. The rotor tip predictions for heat transfer were on average 15.5% greater than the experimental measurements. The rotor blade casing surface heat transfer results are presented in this thesis, however there were no other data for the results to be compared to. Detailed analysis and discussion over the CFD predictions and results are contained in this thesis.

Download or read book Off design Performance Prediction with Experimental Verification for a Radial inflow Turbine written by Samuel M. Futral and published by . This book was released on 1965 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Turbine Aerodynamics written by Ronald H. Aungier and published by American Society of Mechanical Engineers. This book was released on 2006 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a thorough description of actual, working aerodynamic design and analysis systems, for both axial-flow and radial-flow turbines. It describes the basic fluid dynamic and thermodynamic principles, empirical models and numerical methods used for the full range of procedures and analytical tools that an engineer needs for virtually any type of aerodynamic design or analysis activity for both types of turbine. The book includes sufficient detail for readers to implement all or part of the systems. The author provides practical and effective design strategies for applying both turbine types, which are illustrated by design examples. Comparisons with experimental results are included to demonstrate the prediction accuracy to be expected. This book is intended for practicing engineers concerned with the design and development of turbines and related machinery.

Download or read book NASA SP written by and published by . This book was released on 1992 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aerodynamic Pressure and Flow visualization Measurement from a Rotating Wind Turbine Blade written by Charles P. Butterfield and published by . This book was released on 1988 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1997 with total page 940 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 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Commercial Aircraft Propulsion and Energy Systems Research written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2016-08-09 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary human activities that release carbon dioxide (CO2) into the atmosphere are the combustion of fossil fuels (coal, natural gas, and oil) to generate electricity, the provision of energy for transportation, and as a consequence of some industrial processes. Although aviation CO2 emissions only make up approximately 2.0 to 2.5 percent of total global annual CO2 emissions, research to reduce CO2 emissions is urgent because (1) such reductions may be legislated even as commercial air travel grows, (2) because it takes new technology a long time to propagate into and through the aviation fleet, and (3) because of the ongoing impact of global CO2 emissions. Commercial Aircraft Propulsion and Energy Systems Research develops a national research agenda for reducing CO2 emissions from commercial aviation. This report focuses on propulsion and energy technologies for reducing carbon emissions from large, commercial aircraftâ€" single-aisle and twin-aisle aircraft that carry 100 or more passengersâ€"because such aircraft account for more than 90 percent of global emissions from commercial aircraft. Moreover, while smaller aircraft also emit CO2, they make only a minor contribution to global emissions, and many technologies that reduce CO2 emissions for large aircraft also apply to smaller aircraft. As commercial aviation continues to grow in terms of revenue-passenger miles and cargo ton miles, CO2 emissions are expected to increase. To reduce the contribution of aviation to climate change, it is essential to improve the effectiveness of ongoing efforts to reduce emissions and initiate research into new approaches.

Download or read book Aerodynamic Design Performance Predictions of a Single Stage Axial flow Turbine written by Angel Santos and published by . This book was released on 1993 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Two stage Air cooled Turbine Suitable for Flight at Mach Number of 2 5 written by James W. Miser and published by . This book was released on 1956 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: