Download or read book Flow Visualization and Leakage Measurements of Worn Labyrinth Seals written by Brian Frank Allen and published by . This book was released on 1997 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Scale Test Rig for Flow Visualization and Leakage Measurement of Labyrinth Seals written by Daniel Harold Broussard and published by . This book was released on 1991 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flow Visualization and Leakage Measurments of Stepped Labyrinth Seals Part 2 Sloping Surfaces written by David L. Rhode and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine and Aeroengine Congress &Exhibition Birmingham, UK - June 10-13, 1996.
Download or read book Flow Visualization and Leakage Measurments of Stepped Labyrinth Seals Part 1 Annular Groove written by David L. Rhode and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine and Aeroengine Congress &Exhibition Birmingham, UK - June 10-13, 1996.
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 Visualization and measurements of rub groove leakage effects on straight through labyrinth seals ASME 98 GT 506 written by David L. Rhode and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine & Aeroengine Congress & Exhibition, Stockholm, Sweden, Jun 2-5, 1998.
Download or read book Comparison of Experimental and Ideal Leakage Flows Through Labyrinth Seals for Very Small Pressure Differences written by Frederick C. Yeh and published by . This book was released on 1970 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Labyrinth Seal Analysis Volume 3 Analytical and Experimental Development of a Design Model for Labyrinth Seals written by and published by . This book was released on 1986 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: A thorough review of the literature concerning labyrinth seals was conducted and the significant geometric and aerodynamic parameters influencing leakage were identified. An extensive data base was accumulated from published and in-house experimental results as the foundation for the development of a design model for labyrinth seals. Full-size two-dimensional seal geometries were tested to extend the data range in key areas. The empirically based model was developed using statistical methods to define correlating equations based the seal parameters. Comparison of the resulting model to experimental data revealed an accuracy of + or - 5%. Flow visualization studies yielded qualitative descriptions of the internal flow fields and loss mechanisms at work in both straight and stepped labyrinth seals. Measurement of pressures and temperatures in the seal cavities provided data for comparison with theoretical predictions. Hot-wire anemometer data for internal velocity profiles were in qualitative agreement with the Navier-Stokes analyses. Volume I summarizes the labyrinth seal analysis model. Volume II presents the user's manual for the analysis model computer code. Volume III contains the experimental results and summarizes the design model based on these empirical data. Volume IV presents the user's manual for the design model computer code. Keywords: Rotating seals, Contactless seals, Gas path seals, Interstage seals, Air leakage in gas turbines.
Download or read book The Prediction and Measurement of Incompressible Flow in a Labyrinth Seal written by Jonathan Alexander Demko and published by . This book was released on 1986 with total page 338 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 2000 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Land Wear Upon Flow Leakage Through Labyrinth Seals written by David Rex Ek and published by . This book was released on 1984 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Paper written by and published by . This book was released on 2000 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Leakage and Rotordynamic Effects of Pocket Damper Seals and See through Labyrinth Seals written by Ahmed Mohamed Gamal Eldin and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation discusses research on the leakage and rotordynamic characteristics of pocket damper seals (PDS) and see-through labyrinth seals, presents and evaluates models for labyrinth seal and PDS leakage and PDS force coefficients, and compares these seals to other annular gas seals. Low-pressure experimental results are used alongside previously-published high-pressure labyrinth and PDS data to evaluate the models. Effects of major seal design parameters; blade thickness, blade spacing, blade profile, and cavity depth; on seal leakage, as well as the effect of operating a seal in an off-center position, are examined through a series of non-rotating tests. Two reconfigurable seal designs were used, which enabled testing labyrinth seals and PDS with two to six blades. Leakage and pressure measurements were made with air as the working fluid on twenty-two seal configurations. Increasing seal blade thickness reduced leakage by the largest amount. Blade profile results were more equivocal, indicating that both profile and thickness affected leakage, but that the influence of one factor partially negated the influence of the other. Seal leakage increased with increased eccentricity at lower supply pressures, but that this effect was attenuated for higher pressure drops. While cavity depth effects were minor, reducing depths reduced leakage up to a point beyond which leakage increased, indicating that an optimum cavity depth existed. Changing blade spacing produced results almost as significant as those for blade thickness, showing that reducing spacing can detrimentally affect leakage to the point of negating the benefit of inserting additional blades. Tests to determine the effect of PDS partition walls showed that they reduce axial leakage. The pressure drop was found to be highest across the first blade of a seal for low pressure drops, but the pressure drop distribution became parabolic for high pressure drops with the largest drop across the last blade. Thirteen leakage equations made up of a base equations, a flow factor, and a kinetic energy carryover factor were examined. The importance of the carryover coefficient was made evident and a modified carryover coefficient is suggested. Existing fully partitioned PDS models were expanded to accommodate seals of various geometries.
Download or read book Analysis of Compressible and Incompressible Flows Through See through Labyrinth Seals written by Jeng Won Woo and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The labyrinth seal is a non-contact annular type sealing device used to reduce the internal leakage of the working fluid which is caused by the pressure difference between each stage in a turbomachine. Reducing the leakage mass flow rate of the working fluid through the labyrinth seal is desirable because it improves the efficiency of the turbomachine. The carry-over coefficient, based on the divergence angle of the jet, changed with flow parameters with fixed seal geometry while earlier models expressed the carry-over coefficient solely as a function of seal geometry. For both compressible and incompressible flows, the Reynolds number based on clearance was the only flow parameter which could influence the carry-over coefficient. In the case of incompressible flow based on the simulations for various seal geometries and operating conditions, for a given Reynolds number, the carry-over coefficient strongly depended on radial clearance to tooth width ratio. Moreover, in general, the lower the Reynolds number, the larger is the divergence angle of the jet and this results in a smaller carry-over coefficient at lower Reynolds numbers. However, during transition from laminar to turbulent, the carry-over coefficient reduced initially and once the Reynolds number attained a critical value, the carry-over coefficient increased again. In the case of compressible flow, the carry-over coefficient had been slightly increased if radial clearance to tooth width ratio and radial clearance to tooth pitch ratio were increased. Further, the carry-over coefficient did not considerably change if only radial clearance to tooth width ratio was decreased. The discharge coefficient for compressible and incompressible flows depended only on the Reynolds number based on clearance. The discharge coefficient of the tooth in a single cavity labyrinth seal was equivalent to that in a multiple tooth labyrinth seal indicating that flow downstream had negligible effect on the discharge coefficient. In particular, for compressible fluid under certain flow and seal geometric conditions, the discharge coefficient did not increase with an increase in the Reynolds number. It was correlated to the pressure ratio, Pr. Moreover, it was also related to the fact that the flow of the fluid through the constriction became compressible and the flow eventually became choked. At low pressure ratios (less than 0.7), Saikishan's incompressible model deviated from CFD simulation results. Hence, the effects of compressibility became significant and both the carry-over coefficient compressibility factor and the discharge coefficient compressibility factor needed to be considered and included into the leakage model. The carry-over coefficient compressibility factor, phi, had two linear relationships with positive and negative slopes regarding the pressure ratios. This result was not associated with the seal geometry because the seal geometry ratios for each instance were located within the nearly same ranges. Further, the phi-Pr relationship was independent of the number of teeth regardless of single and multiple cavity labyrinth seals. The discharge coefficient compressibility factor, psi, was a linear relationship with pressure ratios across the tooth as Saikishan predicted. However, in certain flow and seal geometric conditions, Saikishan's model needed to be modified for the deviation appearing when the pressure ratios were decreased. Hence, a modified psi-Pr relationship including Saikishan's model was presented in order to compensate for the deviation between the simulations and his model.
Download or read book Leakage Flow in Labyrinth Seals written by Mohammed Ajaz Khan and published by . This book was released on 1991 with total page 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 1994 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
