Download or read book Three Dimensional Unsteady Simulation of Aerodynamics and Heat Transfer in a Modern High Pressure Turbine Stage written by Vikram Shyam and published by BiblioGov. This book was released on 2013-06 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unsteady 3-D RANS simulations have been performed on a highly loaded transonic turbine stage and results are compared to steady calculations as well as to experiment. A low Reynolds number k-epsilon turbulence model is employed to provide closure for the RANS system. A phase-lag boundary condition is used in the tangential direction. This allows the unsteady simulation to be performed by using only one blade from each of the two rows. The objective of this work is to study the effect of unsteadiness on rotor heat transfer and to glean any insight into unsteady flow physics. The role of the stator wake passing on the pressure distribution at the leading edge is also studied. The simulated heat transfer and pressure results agreed favorably with experiment. The time-averaged heat transfer predicted by the unsteady simulation is higher than the heat transfer predicted by the steady simulation everywhere except at the leading edge. The shock structure formed due to stator-rotor interaction was analyzed. Heat transfer and pressure at the hub and casing were also studied. Thermal segregation was observed that leads to the heat transfer patterns predicted by steady and unsteady simulations to be different.

Download or read book 3 D Unsteady Simulation of a Modern High Pressure Turbine Stage written by Vikram Shyam and published by . This book was released on 2010 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This is the first 3-D unsteady RANS simulation of a highly loaded transonic turbine stage and results are compared to steady calculations and experiments. A low Reynolds number [kappa]-[epsilon] turbulence model is employed to provide closure for the RANS system. Phase-lag is used in the tangential direction to account for stator-rotor interaction. Due to the highly loaded characteristics of the stage, inviscid effects dominate the flowfield downstream of the rotor leading edge minimizing the effect of segregation to the leading edge region of the rotor blade. Unsteadiness was observed at the tip surface that results in intermittent 'hot spots'. It is demonstrated that unsteadiness in the tip gap is governed by both inviscid and viscous effects due to shock-boundary layer interaction and is not heavily dependent on pressure ratio across the tip gap. This is contrary to published observations that have primarily dealt with subsonic tip flows. The high relative Mach numbers in the tip gap lead to a choking of the leakage flow that translates to a relative attenuation of losses at higher loading. The efficacy of a new tip geometry is discussed to minimize heat flux at the tip while maintaining choked conditions. Simulated heat flux and pressure on the blade and hub agree favorably with experiment and literature. The time-averaged simulation provides a more conservative estimate of heat flux than the steady simulation. The shock structure formed due to stator-rotor interaction is analyzed. A preprocessor has also been developed as a conduit between the unstructured multi-block grid generation software GridPro and the CFD code TURBO.

Download or read book Three dimensional Unsteady Parallel Simulation of a Multi stage Turbine with Conjugate Heat Transfer written by Daryl Yao-Wah Lee and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational fluid dynamics (CFD) procedure has been developed to predict the three-dimensional unsteady flow through a multi-stage axial turbine including the effects of heat transfer. This procedure simultaneously solves the unsteady Reynold's-averaged Navier-Stokes equations for the flow along with the heat conduction equation for the solid. Solution time is minimized through the use of multiple central processing units (CPUs).The blades of the multi-stage turbine move in time and the flow interacts with adjacent vane (stationary) passages through the use of a parallel, sliding-grid, inter-blade-row treatment. Described are the techniques used to solve the governing equations, the inter-blade-row treatment, and the parallelization of the overall approach. The uniqueness of this prediction method lies in the unsteady, multi-stage conjugate solution and the use of multiple combined cores. The approach is validated for the High Impact Technology Turbine designed and tested at the Air Force Research Laboratory.

Download or read book An Experimental Investigation of Clocking Effects on Turbine Aerodynamics Using a Modern 3 D One and One half Stage High Pressure Turbine for Code Verification and Flow Model Development written by Charles W. Haldeman and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: A modern 1 and 1/2 stage high-pressure (HP) turbine operating at the proper design corrected speed, pressure ratio, and gas to metal temperature ratio is used to generate a detailed data set containing aerodynamic, heat-transfer and aero-performance information. The data was generated using the Ohio State University Gas Turbine Laboratory Turbine Test Facility (TTF), a short-duration shock tunnel facility. The research program utilizes an uncooled turbine stage for which all three airfoils are heavily instrumented at multiple spans and on the HPV and LPV endwalls and HPB platform and tips. Heat-flux and pressure data are obtained using traditional shock-tube and blowdown facility operational modes. The aerodynamic (pressure) data obtained is the same in both modes when the corrected conditions are matched. Various experimental conditions and configurations were performed, including LPV clocking positions, off-design corrected speed conditions, pressure ratio changes, and Reynolds number changes. The main focus of this dissertation is the LPV clocking experiments, where the LPV was clocked relative to the HPV at several different passage locations and at different Reynolds numbers. Various methods were used to evaluate the effect of clocking on both the aeroperformance (efficiency) and aerodynamics (pressure loading) on the LPV, including time-resolved measurements, time-averaged measurements and stage performance measurements. A general improvement in overall efficiency of approximately 2% is demonstrated and could be observed using a variety of independent methods. Maximum efficiency is obtained when the time-average pressures are highest on the LPV, and the time-resolved data both in the time domain and frequency domain show the least amount of variation. The gain in aeroperformance is obtained by integrating over the entire airfoil as the three-dimensional effects on the LPV surface are significant.

Download or read book Aerodynamic and Mechanical Performance written by Geoff Sheard and published by LAP Lambert Academic Publishing. This book was released on 2011-01 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unsteady three-dimensional flow phenomena have major effects on the aerodynamic performance of, and heat transfer to, gas-turbine blading. Investigation of the mechanisms associated with these phenomena requires an experimental facility that is capable of simulating a gas turbine, but at lower levels of temperature and pressure to allow conventional measurement techniques. This book reports on the design, development and commissioning of a new experimental facility that models these unsteady three-dimensional flow phenomena. The new facility, which consists of a 62%-size, high-pressure gas- turbine stage mounted in a transient wind tunnel, simulates the turbine design point of a full-stage turbine. The book describes the aerodynamic and mechanical design of the new facility, a rigorous stress analysis of the facility's rotating system and the three-stage commissioning of the facility. The book concludes with an assessment of the turbine stage performance.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unsteady Three Dimensional Navier Stokes Analysis of a Hot Streak Transport Through an Axial High Pressure Turbine Stage written by L. Castillon and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aerodynamics and Heat Transfer for a Modern Stage and One half Turbine written by Matthew Lee Krumanaker and published by . This book was released on 2003 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 ASME Technical Papers written by and published by . This book was released on 1984 with total page 670 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 Three Dimensional Flow and Temperature Profile Attenuation in an Axial Flow Turbine written by David H. Joslyn and published by . This book was released on 1989 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: While strongly three dimensional and highly unsteady nature of the flow in axial turbines has, until recently, defied in-depth analysis, the benefits that can be realized from an improved capability to predict the aerodynamics and heat transfer in turbines are numerous. These benefits include improved performance through higher efficiency, higher thrust-to-weight ratio through higher turbine inlet temperature, and improved durability through more precise predictions of local heat load. This program was particularly interested in the aerodynamic mechanisms affecting attenuation of a radial temperature profile in the flow as it passed through the turbine. The radial temperature profile in the flow exiting a combustor and entering a turbine can range from compressor exit temperature (approx = 1100 F) near the hub and tip end walls to a maximum (as high as 3200 F) in the midspan region. The heat load at any location on the turbine airfoils or end walls depends strongly on the local gas temperature at that location; hence the mixing, or attenuation, of the inlet temperature profile is of critical importance. This program has advanced the state-of-the-art by providing: 1) an exhaustive aerodynamic data base for the three dimensional flow in a large scale axial turbine; 2) an exhaustive data base documenting the mixing of a simulated combustor exit temperature profile as it passed through the turbine; and 3) an assessment of sota three dimensional time accurate, Navier-Stokes prediction of the flow in the turbine stage. Keywords: Temperature redistribution. (EDC).

Download or read book Turbomachinery Flow Physics and Dynamic Performance written by Meinhard T. Schobeiri and published by Springer Science & Business Media. This book was released on 2004-11-12 with total page 535 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past three decades turbomachines experienced a steep increase in efficiency and performance. Based on fundamental principles of turbomachinery thermo-fluid mechanics, numerous CFD based calculation methods are being developed to simulate the complex 3-dimensional, highly unsteady turbulent flow within turbine or compressor stages. The objective of this book is to present the fundamental principals of turbomachinery fluid-thermodynamic design process of turbine and compressor components, power generation and aircraft gas turbines in a unified and compact manner. The book provides senior undergraduate students, graduate students and engineers in the turbomachinery industry with a solid background of turbomachinery flow physics and performance fundamentals that are essential for understanding turbomachinery performance and flow complexes.

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1048 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeronautical Engineering written by and published by . This book was released on 1991 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unsteady Aerodynamics and Heat Transfer in a Transonic Turbine Stage written by D. A. Ashworth and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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: