Download or read book Continued Investigation of Leakage and Power Loss Test Results for Competing Turbine Engine Seals written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-24 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Secondary seal leakage in jet engine applications results in power losses to the engine cycle. Likewise, seal power loss in jet engines not only result in efficiency loss but also increase the heat input into the engine resulting in reduced component lives. Experimental work on labyrinth and annular seals was performed at NASA Glenn Research Center to quantify seal leakage and power loss at various temperatures, seal pressure differentials, and surface speeds. Data from annular and labyrinth seals are compared with previous brush and finger seal test results. Data are also compared to literature. Annular and labyrinth seal leakage rates are 2 to 3 times greater than brush and finger seal rates. Seal leakage decreases with increasing speed but increases with increasing test temperature due to thermal expansion mismatch. Also seal power loss increases with surface speed, seal pressure differential, mass flow rate, and radial clearance. Annular and labyrinth seal power losses were higher than those of brush or finger seal data. The brush seal power loss was 15 to 30 percent lower than annular and labyrinth seal power loss. Delgado, Irebert R. and Proctor, Margaret P. Glenn Research Center NASA/TM-2006-214420, ARL-MR-0643, AIAA Paper 2006-4754, E-15638

Download or read book Leakage and Power Loss Test Results for Competing Turbine Engine Seals written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-21 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced brush and finger seal technologies offer reduced leakage rates over conventional labyrinth seals used in gas turbine engines. To address engine manufacturers concerns about the heat generation and power loss from these contacting seals, brush, finger, and labyrinth seals were tested in the NASA High Speed, High Temperature Turbine Seal Test Rig. Leakage and power loss test results are compared for these competing seals for operating conditions up to 922 K (1200 F) inlet air temperature, 517 KPa (75 psid) across the seal, and surface velocities up to 366 m/s (1200 ft/s). Proctor, Margaret P. and Delgado, Irebert R. Glenn Research Center NASA/TM-2004-213049, GT2004-53935, E-14452

Download or read book Leakage and Power Loss Test Results for Competing Turbine Engine Seals written by and published by . This book was released on 2004 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced brush and finger seal technologies offer reduced leakage rates over conventional labyrinth seals used in gas turbine engines. To address engine manufacturers' concerns about the heat generation and power loss from these contacting seals, brush, finger, and labyrinth seals were tested in the NASA High Speed, High Temperature Turbine Seal Test Rig. Leakage and power loss test results are compared for these competing seals for operating conditions up to 922 K (1200 degrees F) inlet air temperature, 517 KPa (75 psid) across the seal, and surface velocities up to 366 m/s (1200 ft/s).

Download or read book Advances in Mechanical Design written by Jianrong Tan and published by Springer Nature. This book was released on 2019-09-14 with total page 1154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focusing on innovation, these proceedings present recent advances in the field of mechanical design in China and offer researchers, scholars and scientists an international platform for presenting their research findings and exchanging ideas. Gathering outstanding papers from the 2019 International Conference on Mechanical Design (2019 ICMD) and the 20th Mechanical Design Annual Conference, the content is divided into six major sections: industrial design, reliability design, green design, intelligent design, bionic design and innovative design. Readers will learn about the latest trends, cutting-edge findings and hot topics in the field of design.

Download or read book Material Engineering And Mechanical Engineering Proceedings Of Material Engineering And Mechanical Engineering Meme2015 written by Huiyu Zhou and published by World Scientific. This book was released on 2016-05-26 with total page 1538 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of proceeding of International Conference on Material Engineering and Mechanical Engineering [MEME2015] is to provide a platform for researchers, engineers, and academicians, as well as industrial professionals, to present their research results and applications developed for Material Engineering and Mechanical Engineering. It provides an opportunities for the delegates to exchange new ideas and application experiences, to enhance business or research relations and to find global partners for future collaboration. The object is to strengthen national academic exchanges and cooperation in the field, promote the rapid development of machinery, materials science and engineering application, effectively improve China's machinery, materials science and engineering applications in the field of academic status and international influence.

Download or read book Research in Interactive Design Vol 4 written by Xavier Fischer and published by Springer. This book was released on 2016-03-02 with total page 637 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering key topics in the field such as technological innovation, human-centered sustainable engineering and manufacturing, and manufacture at a global scale in a virtual world, this book addresses both advanced techniques and industrial applications of key research in interactive design and manufacturing. Featuring the full papers presented at the 2014 Joint Conference on Mechanical Design Engineering and Advanced Manufacturing, which took place in June 2014 in Toulouse, France, it presents recent research and industrial success stories related to implementing interactive design and manufacturing solutions.

Download or read book The Experimental and Numerical Investigation of the Influence of Shaft Rotation on Leakage Rate of Non contacting Seals Found in Turbine Applications written by Jacobus Johannes Fourie Wiid and published by . This book was released on 2018 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project was initiated by ESKOM power generation. ESKOM loses up to 22% of their steam energy in the HP turbines due to leakage at the turbine labyrinth seals. Therefore the need was expressed their need to implement improved sealing configurations. The aim of this study is to investigate the effect that shaft rotation has on the leakage rate of labyrinth and brush seals. This is done by means of experimental and numerical methods. For many decades it was assumed that the shaft rotation has no or little effect on seal performance and therefore it was neglected in seal design. It was decided to investigate this subject, in order to assist and improve in future seal design and operation. Both labyrinth and brush seals were investigated experimentally on a test rig. A real life application of the labyrinth or brush seals can be found in the power generation industry where a turbine shaft has a diameter of 300 mm and rotates at 3 000 rpm. The test rig was designed to assist in this application. Therefor the test rig had a shaft diameter of 150 mm with shaft speeds ranging between 0-10 000 rpm and with five different upstream pressures ranging from 1-5 bar. The same seals were then simulated using the commercial Computational Fluid Dynamics (CFD) package STAR-CCM+ with the bristle pack of the brush seal modelled as a porous medium. The coefficients of resistance for the porous medium were experimentally obtained. The two investigation methods are compared for the labyrinth and brush seals. The labyrinth and brush seals are also compared against each other. The results show that the experimental leakage rates have a good correlation with those predicted by CFD. The CFD simulation provided detailed leakage flow fields and pressure distributions of both seals. It was found that shaft rotation has an influence on the leakage rate of both seals. The leakage rate increased at higher shaft speeds, with the brush seal performing better than the labyrinth seal. An increase of up to 1.7% was found at 10 000 rpm for the labyrinth seal and 1.45% for the brush seal at 10 000 rpm. Guidelines were created based on these results to assist with advanced seal design. It is recommended that these guidelines are used in future seal design and other research aspects of non-contacting seals in turbo machinery.

Download or read book Performance and Analysis of Seals for Inerted Lubrication Systems of Turbine Engines written by Robert L. Johnson and published by . This book was released on 1968 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Power Dissipation in Smooth and Honeycomb Labyrinth Seals written by and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The surface frictional characteristics of a labyrinth seal can result in significant windage power dissipation for high speed seals. Recent advances in seal design have produced high speed, high pressure labyrinth seals which operate at very low leakage rates. The reduced leakage is beneficial to gas turbine efficiency, but seal discharge temperatures can approach material design limits with high windage power dissipation. Also, a high air temperature rise can influence seal leakage flow. Consequently, the general assumption of negligible rotational effect on leakage is not always valid. A method is presented for the prediction of seal power dissipation and leakage flow over a wide range of design parameters. Results are compared to available test data and several approaches examined for the reduction of seal windage.

Download or read book Gas Seal Leakage at High Temperature written by Alain Anderson and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Reducing secondary leakage is a common challenge in numerous machines, particularly in steam and gas turbines. Too large leakage in seals produces a substantial loss in efficiency and power delivery with an increase in specific fuel consumption. Various seal types exist, each with unique advantages and disadvantages as per leakage, power loss, and wear. Labyrinth seals are most common due to their simple design and low cost. Their main drawback is a too high leakage due to enlarged (worn) clearances when a rotor vibrates. More complicated seal types, such as brush seals can withstand rotor excursions and ensure lower leakage rates than with labyrinth seals. Brush seals utilize a bristle bed which contacts the rotor and wears out thereby reducing leakage performance. The HALO[superscript TM] seal, an all-metal seal with flexibly supported shoes, is engineered as a clearance control seal to reduce leakage even more, in particular for operation with high pressure differentials and with high surface rotor speeds. Static leakage tests with hot air at a high temperature (max. 300°C) conducted in a test rig holding a labyrinth seal and a novel all-metal seal (HALO[superscript TM] seal), both of the same diameter, length and clearance, show the novel seal leaks ~1/5 the flow of a labyrinth seal for pressure ratios (P[subscript s]/P[subscript a]) > 3.5. The savings in leakage are maximized during operation at high pressure differentials. Leakage measurements with a rotor spinning to a maximum speed of 2,700 rpm (surface speed = 23.6 m/s) produce a slight decrease in leakage with increasing rotor speed. The research product is a reliable leakage data base enabling the application of a state of the art sealing technology that increases system efficiency by reducing leakage and extends maintenance intervals by eliminating wear of components. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151242

Download or read book Exploratory Investigation for Reducing Labyrinth Seal Leakage in High Pressure Ratio Gas Turbines written by H. L. Stocker and published by . This book was released on 1973 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The attendant problem of labyrinth seal air leakage in current and advanced high pressure ratio gas turbines is directly related to the limitations of current gas turbine dynamic seal technology. A method of improving the efficiency of labyrinth seals which does not violate mechanical design constraints involves increasing the internal cavity turbulence of the seal. Therefore, an exploratory investigation was undertaken to conceive, design, fabricate, and test several unique labyrinth seal configurations. (Modified author abstract).

Download or read book Pressure Balanced Low Hysteresis Finger Seal Test Results written by Gul K. Arora and published by . This book was released on 1999 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The finger seal is a revolutionary new technology in air to air sealing for secondary flow control and gas path sealing in gas turbine engines. Though the seal has been developed for gas turbines, it can be easily used in any machinery where a high pressure air cavity has to be sealed from a low pressure air cavity, for both static and rotating applications. This seal has demonstrated air leakage considerably less than a conventional labyrinth seal and costs considerably less than a brush seal. A low hysteresis finger seal design was successfully developed and tested in a seal rig at NASA Glenn Research Center. A total of thirteen configurations were tested to achieve the low hysteresis design. The best design is a pressure balanced finger seal with higher stiffness fingers. The low hysteresis seal design has undergone extensive rig testing to assess its hysteresis, leakage performance and life capabilities. The hysteresis, performance and endurance test results are presented. Based on this extensive testing, it is determined that the finger seal is ready for testing in an engine.

Download or read book Static and Rotating Air Gas Seal Evaluation written by W. Paladini and published by . This book was released on 1971 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report describes an evaluation of the leakage characteristics of current gas turbine engine air/gas seals and sealing surfaces of small gas turbine engines. The evaluation included definition of probable air/gas leakage sources and paths in an engine possessing variable compressor and power turbine stator geometry, identification of sealing concepts currently in use, prediction of seal leakage in the small engine, rig testing of several static and rotating seals, and analysis of the effect of leakage on small engine performance. The rotating shaft seal tests were conducted on a fin-to-fin labyrinth seal and a carbon face contact seal. The casing flange seal tests were conducted on metal-to-metal surfaces and on four metal seals for flanges. The variable-geometry vane trunnion seal tests were conducted on a fluorocarbon bushing and a metal bushing for the compressor and power turbine locations, respectively. Testing included leakage calibrations, and thermal cyclic and mechanical cyclic operation. (Author).

Download or read book Labyrinth Seal Leakage Analysis written by Orcun Inam and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Annular seals are devices used in turbomachinery to avoid flow losses which reduce efficiency. The dynamic stability of the machine is also improved by the seal. Thus, it is an important subject to understand the flow behavior through the seal. Straight through triangular labyrinth seals are one of the most commonly used types of non-contacting annular seals. The energy dissipation through these seals is achieved by a series of teeth and cavities. As the flow passes above each tooth, a portion of its pressure energy is converted into kinetic energy. A portion of this kinetic energy is dissipated through turbulence-viscosity interaction in the cavity that follows. Moreover, some portion of the pressure energy is also lost through viscosity of the fluid. This research aims to understand the effects of flow parameters and seal geometry on these losses. This will make it possible to estimate the mass flow leakage through the seal. ANSYS Fluent is used to simulate the flow through the seal. The effect of seal geometry is studied by varying clearance, pitch, tooth height, tooth width and upstream side angle. It was found that, amongst other geometrical parameters, tooth clearance and pitch has a strong influence on carryover coefficient. Smaller values of c/s have better kinetic energy dissipation in the cavity. Carryover coefficient is also found to be a function of the Reynolds number and shaft speed. Discharge coefficient of the seal presents the overall efficiency while carryover coefficient only shows the cavity performance. Discharge coefficient is also found to be a strong function of tooth clearance, pitch, Reynolds number and shaft speed. Remaining parameters have smaller effects. It was observed that the discharge coefficient of first tooth is always lower than those of intermediate teeth. The compressibility effects are presented by using an expansion factor which is the ratio of compressible flow discharge coefficient to incompressible flow discharge coefficient. It was found that the expansion factor is fairly independent of geometrical parameters but a strong function of flow parameters. Considering the effects of seal geometry and flow parameters on carryover coefficient, discharge coefficient and expansion factor, the seal geometry is optimized to increase the kinetic energy dissipation and pressure head loss which in turn will reduce the mass flow leakage.

Download or read book An Investigation of the Performance of Compliant Finger Seals for Use in Gas Turbine Engines Using Navier stokes and Reynolds Equation Based Numerical Models and Experimental Evaluation written by Sara E. Kline and published by . This book was released on 2016 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work analyzed the performance of two foot pad designs for the compliant finger seal. The double wedge and Rayleigh step pad designs were tested numerically and experimentally. The numerical models were solved using ANSYS CFX and compared to the experimental results. A finite difference based two dimensional model of the fluid film under the pad solving the Reynolds equation coupled with the energy equation was also formulated.The double wedge and Rayleigh step seal pad designs were analyzed using ANSYS CFX. Models matching the design drawings for the actual seal, and models with increased gap heights were created. The models consisted of one or two non-padded feet, padded feet, and the interstices between subsequent feet. Cases were run at rotational speeds of 2 krpm to 12 krpm in 2 krpm increments and at pressures of 5, 20, 25, and 30 psig, which matches the experimental cases. The small gap geometry was run as laminar compressible while the large gap geometry was run as turbulent compressible, and all were run as isothermal. The mass leakage was found to increase with increasing pressure for all models tested. For the double wedge seal and the Rayleigh step seal with the larger gap, the leakage did not change significantly with increasing rotation, but the leakage is affected by the rotation in the Rayleigh step seal with the original gap. Previously unseen compressibility effects, such as potential choking of the flow, were witnessed in the numerical models for the geometries with the larger gaps. Both the double wedge and Rayleigh step seal pad designs were experimentally tested, and the experimental cases matched the parameters of the numerical cases. The results of the experiments on the double wedge seal indicated that as the high side pressure increased, the mass leakage remained relatively unchanged, and the mass leakage was found to decrease with increasing speed. The leakage of the Rayleigh step seal followed a similar trend as the double wedge seal as the high side pressure was increased, however, the leakage of the Rayleigh step seal increased slightly due to higher rotation. The temperature of the seal pads did not change significantly during testing for either seal pad design indicating there was no contact between the rotor and the seal.The results of the numerical models and the experiment were compared. The mass leakage values of the experimental results were an order of magnitude higher than those of the numerical models with the small gap, and compared much better with the large gap model. The higher mass leakage results are likely due to the higher leakage due to the actual seal being warped, and the actual seal possibly having a larger gap height than the model. These issues make comparing the experimental and numeric results difficult.A two dimensional Reynolds equation based solver was written to model the fluid film under a single foot pad. The Reynolds equation is coupled with the energy equation and solved using finite differences. The model was validated by comparing the results with those from a three dimensional Navier-Stokes based model run in ANSYS CFX. The Reynolds based model compared well with the Navier-Stokes model, both qualitatively and quantitatively. Thus, the Reynolds based model provides a fast, effective method of comparing foot pad designs.

Download or read book Labyrinth Seal Leakage Analysis written by Gaurav Chaudhary and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Seals are basic mechanical devices commonly used in machinery to avoid undesired flow losses of working fluids. To understand the working of these seals specifically those placed between relatively moving parts is still one of the major engineering challenges for the scientific community. Particularly Annular seals are one of the most widely used in rotating machinery comprising turbines, compressors and pumps. They are mounted on the shaft that rotates within a stationary case. These seal designs make an impact on (i) machinery energy conversion efficiency and (ii) rotor dynamic stability due to the interaction between rotor and stator through fluid flow leakage. Among all annular seals straight through rectangular labyrinth seals are the most commonly used ones. Their designs have not changed much a lot since its inception by C.J. Parsons [1] back in 1901. These seals provide resistance to the fluid flow through tortuous path comprising of series of cavities and clearances. The sharp tooth converts the pressure energy to the kinetic which is dissipated through turbulence viscosity interaction in the cavity. To understand the accurate amount of leakage the flow is modeled using the discharge coefficient and for each tooth and the kinetic energy carry over coefficients. This research work is aimed at understanding the fluid flow though labyrinth seals with tooth mounted on the rotor. A matrix of fluid flow simulations has been carried out using commercially available CFD software Fluent® where all parameters effecting the flow field has been studied to understand their effect on the coefficients defining the seal losses. Also the rotor surface speed has been used varied in a step by step manner to understand the fluid flow behavior in high speed turbo-machinery. The carry over coefficient is found to be the function of all the geometric elements defining the labyrinth tooth configuration. A relation between the flow parameters and the carry over coefficient has also been established. The discharge coefficient of the first tooth has been found to be lower and varying in a different manner as compared to a tooth from a multiple cavity seal. Its dependence upon flow parameters and dimensionless geometric constants has been established. The discharge coefficient of the first teeth is found to be increasing with increasing tooth width. Further the compressibility factor has been defined to incorporate the deviation of the performance of seals with compressible fluid to that with the incompressible flow. Its dependence upon pressure ratio and shaft speed has also been established. Using all the above the mentioned relations it would be easy decide upon the tooth configuration for a given rotating machinery or understand the behavior of the seal currently in use.

Download or read book Gas Turbine Engine Static Strip Seals written by Arash Farahani and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: