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Numerical Simulation Of The Flow Field In 3d Eccentric Annular And 2d Centered Labyrinth Seals For Comparison With Experimental Lda Data
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Book Synopsis Numerical Simulation of the Flow Field in 3D Eccentric Annular and 2D Centered Labyrinth Seals for Comparison with Experimental LDA Data by : Anand Vijaykumar
Download or read book Numerical Simulation of the Flow Field in 3D Eccentric Annular and 2D Centered Labyrinth Seals for Comparison with Experimental LDA Data written by Anand Vijaykumar and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The flow field in an annular seal is simulated for synchronous circular whirl orbits with 60Hz whirl frequency and a clearance/radius ratio of 0.0154 using the Fluent Computational Fluid Dynamics (CFD) code. Fluent's Moving Reference Frame model (MRF) is used to render the flow quasi-steady by making transformations to a rotating frame. The computed flow fields for velocity, pressure and shear stress measurements are compared with the experimental data of Winslow, Thames and Cusano. The CFD predictions are found to be in good agreement with the experimental results. The present CFD methodology can be extended to other whirl frequencies and clearances. The dynamic wall pressure distributions in an annular seal for non-circular whirl orbits were obtained using CFD. The simulations were performed using a time dependant solver utilizing Fluent's Dynamic Mesh model and User Defined Functions (UDFs). The wall pressure distributions obtained from the simulations are compared with data of Cusano. The CFD simulations over predicted the pressure field when compared to experimental results however the general trends in pressure contours are similar. The flow fields for varying rotor eccentricities are also studied by performing coordinate transformations and rendering the flow quasi-steady at set eccentricities using Fluent's MRF model. The computed velocity and pressure fields are compared with the time dependant solution obtained using Fluent's Dynamic Mesh model and UDFs for the same eccentricity. Good agreement in the velocity fields is obtained; however the pressure fields require further investigation. 2D Labyrinth seal simulations were performed for comparisons with experimental LDA data from Johnson. The velocity fields match the experimental LDA data to a fair degree of extent; however, Fluent simulations under predicted the secondary recirculation zones in Labyrinth Backward Swirl (LBS) case.
Book Synopsis Numerical Simulation of Flow in a Whirling Annular Seal and Comparison With Experiments by :
Download or read book Numerical Simulation of Flow in a Whirling Annular Seal and Comparison With Experiments written by and published by . This book was released on 1996 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Labyrinth Seal Analysis. Volume 3. Analytical and Experimental Development of a Design Model for Labyrinth Seals by :
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.
Book Synopsis Comparison of Experimental and Ideal Leakage Flows Through Labyrinth Seals for Very Small Pressure Differences by :
Download or read book Comparison of Experimental and Ideal Leakage Flows Through Labyrinth Seals for Very Small Pressure Differences written by and published by . This book was released on 1970 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Glossary of Prosthodontic Terms by :
Download or read book The Glossary of Prosthodontic Terms written by and published by . This book was released on 1994 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Numerical Simulation of Incompressible Viscous Flow by : Roland Glowinski
Download or read book Numerical Simulation of Incompressible Viscous Flow written by Roland Glowinski and published by Walter de Gruyter GmbH & Co KG. This book was released on 2022-09-20 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book on finite element-based computational methods for solving incompressible viscous fluid flow problems shows readers how to apply operator splitting techniques to decouple complicated computational fluid dynamics problems into a sequence of relatively simpler sub-problems at each time step, such as hemispherical cavity flow, cavity flow of an Oldroyd-B viscoelastic flow, and particle interaction in an Oldroyd-B type viscoelastic fluid. Efficient and robust numerical methods for solving those resulting simpler sub-problems are introduced and discussed. Interesting computational results are presented to show the capability of methodologies addressed in the book.
Download or read book Modelling Fluid Flow written by János Vad and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modelling Fluid Flow presents invited lectures, workshop summaries and a selection of papers from a recent international conference CMFF '03 on fluid technology. The lectures follow the current evolution and the newest challenges of the computational methods and measuring techniques related to fluid flow. The workshop summaries reflect the recent trends, open questions and unsolved problems in the mutually inspiring fields of experimental and computational fluid mechanics. The papers cover a wide range of fluids engineering, including reactive flow, chemical and process engineering, environmental fluid dynamics, turbulence modelling, numerical methods, and fluid machinery.
Book Synopsis Numerical Simulation of Mechanical and Thermal Fluid-structure Interaction in Labyrinth Seals by : Yu Du
Download or read book Numerical Simulation of Mechanical and Thermal Fluid-structure Interaction in Labyrinth Seals written by Yu Du and published by . This book was released on 2010 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Experimental Measurement and Analysis of Wall Pressure Distribution for a 50% Eccentric Whirling Annular Seal by : Arun Suryanarayanan
Download or read book Experimental Measurement and Analysis of Wall Pressure Distribution for a 50% Eccentric Whirling Annular Seal written by Arun Suryanarayanan and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In any rotating machinery, the geometry of the seal influences the extent of systemleakage. The path taken by the flow in the clearance volume is dependent on the seal and rotor profile. The clearance between a new "seal-rotor" combination is uniform except for small variations during manufacturing and assembly. With time this annular cross section undergoes further physical changes causing non-uniform flow in the annular volume. This azimuthally varying leakage through the seal-rotor annulus creates unbalanced forces on the rotor causing it to whirl. It is essential to identify the reasons for these unwanted forces. Velocity profiling of the clearance volume flow was performed by Morrison et al. (1992) using 3-D LDA measurements on annular and labyrinth seals operating with 50% dynamic eccentricities and a whirl ratio of one. However, this alone does not provide a complete matrix of data for the conditions prevailing in the clearance zone. Additional information of mean and instantaneous wall pressure distributions for 0%, 10%, 25% and 50% rotor dynamic eccentricity for whirl ratios of zero and one, with positive pre-swirl, no pre-swirl and negative pre-swirl conditions were measured by Robic (1999). The data collected showed that the pressure field on the seal walls reversed itself between the whirling and non-whirling conditions. As a continuance of the earlier works, the present effort investigates the effect of whirl ratio variation for a 50% eccentric smooth annular seal at a leakage Reynolds number of 24000. An attempt has been made to collect pressure data for negative whirl ratios also under similar test conditions. A seal test rig capable of handling different eccentricities and whirl ratios simultaneously was designed and constructed for this purpose. Mean and instantaneous wall pressure data were recorded for 50% eccentricity with whirl ratios between ł 1 for a rotor speed of 1800. For a rotor speed of 2700, whirl ratios tested were between ł 0.6 and for 3600 rotor speed, whirl ratios ranging between ł 0.5 were tested. From the collected data a detailed analysis of wall pressures along the seal surface is performed following the technique described by Winslow (1994) and Robic (1999).
Book Synopsis Experimental and Numerical Analysis of the Effect of Swirl on the Pressure Field in Whirling Annular and Labyrinth Seals by : Bernard Francois Robic
Download or read book Experimental and Numerical Analysis of the Effect of Swirl on the Pressure Field in Whirling Annular and Labyrinth Seals written by Bernard Francois Robic and published by . This book was released on 1999 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Numerical Simulation of 3-D Incompressible Unsteady Viscous Laminar Flows by : Michel Deville
Download or read book Numerical Simulation of 3-D Incompressible Unsteady Viscous Laminar Flows written by Michel Deville and published by Vieweg+Teubner Verlag. This book was released on 1992-01-01 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt: The GAMM-Commi ttee for Numerical Methods in Fluid Mechanics (GAMM-Fachausschuss für Numerische Methoden in der Strömungsmechanik) has sponsored the organization of a GAMM Workshop dedicated to the numerical simulation of three dimensional incompressible unsteady viscous laminar flows to test Navier-Stokes solvers. The Workshop was held in Paris from June 12th to June 14th, 1991 at the Ecole Nationale Superieure des Arts et Metiers. Two test problems were set up. The first one is the flow in a driven-lid parallelepipedic cavity at Re = 3200 . The second problem is a flow around a prolate spheroid at incidence. These problems are challenging as fully transient solutions are expected to show up. The difficulties for meaningful calculations come from both space and temporal discretizations which have to be sufficiently accurate to resol ve detailed structures like Taylor-Görtler-like vortices and the appropriate time development. Several research teams from academia and industry tackled the tests using different formulations (veloci ty-pressure, vortici ty velocity), different numerical methods (finite differences, finite volumes, finite elements), various solution algorithms (splitting, coupled, ... ), various solvers (direct, iterative, semi-iterative) with preconditioners or other numerical speed-up procedures. The results show some scatter and achieve different levels of efficiency. The Workshop was attended by about 25 scientists and drove much interaction between the participants. The contributions in these proceedings are presented in alphabetical order according to the first author, first for the cavi ty problem and then for the prolate spheroid problem. No definite conclusions about benchmark solutions can be drawn.
Author :Gabriel Sottas Publisher :Notes on Numerical Fluid Mechanics and Multidisciplinary Design ISBN 13 : Total Pages :252 pages Book Rating :4.F/5 ( download)
Book Synopsis 3D-Computation of Incompressible Internal Flows by : Gabriel Sottas
Download or read book 3D-Computation of Incompressible Internal Flows written by Gabriel Sottas and published by Notes on Numerical Fluid Mechanics and Multidisciplinary Design. This book was released on 1993 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of the 1989 GAMM Workshop on 3D-Computation of Incompressible Internal Flows was the simulation of a realistic incompressible flow field in an important industrial application. In view of the difficulties involved in formulating such a test case, requiring the availability of an experimental data base, extreme care had to be taken in the selection of the proper one. Professor I. L. Ryhming's proposal, that the flow through a Francis turbine configuration or parts thereof would be feasible as a test case, because of the numerical challenges as well as the possibility to produce an experimental data base by using the experimental facilities of the Hydraulic Machines and Fluid Mechanics Institute (IMHEF) at the Swiss Federal Institute of Technology in Lausanne (EPFL), was accepted by the GAMM Committee in April 1987. A scientific committee, formed under the chairmanship of Professor I. L. Ryhming, met a few times to decide on the Francis turbine configuration, the test case specifications, etc. , whereby the design input came from the water turbine experts. This committee decided to restrict the studies to the three following typical applications for the best operating point of the turbine: • simulation of the 3D flow in a Francis runner in rotation • simulation of the 3D flow in the distributor (stay and guide vane rings) of this turbine • simulation of the 3D flow in an elbow draft tube The simultaneous computation of two or three of these geometries was encouraged.
Book Synopsis Numerical Simulation of 3-D Incompressible Unsteady Viscous Laminar Flows by : Michel Deville
Download or read book Numerical Simulation of 3-D Incompressible Unsteady Viscous Laminar Flows written by Michel Deville and published by . This book was released on 2014-01-15 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Numerical Simulation of Mechanical and Thermal Fluidstruckture Interaction Ind Labyrinth Seals by : Yu Du
Download or read book Numerical Simulation of Mechanical and Thermal Fluidstruckture Interaction Ind Labyrinth Seals written by Yu Du and published by . This book was released on 2010 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Comparative Investigation of Corresponding Annular and Labyrinth Seal Flowfields by : D. L. Rhode
Download or read book A Comparative Investigation of Corresponding Annular and Labyrinth Seal Flowfields written by D. L. Rhode and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A previous Navier-Stokes finite difference computer code is extended in order to compute seal leakage directly from given upstream and downstream reservoir pressures. The numerical results are in excellent agreement with previous measurements, the discrepancy being less than eight percent. Annual seals are found to leak approximately twenty percent more than corresponding labyrinths over the entire range of realistic clearance. A rather unexpected finding is that a dramatic increase of swirl velocity occurs near the discharge of small clearance annular seals, which does not arise in corresponding labyrinth seals. The results, which are used to explain this finding, show that a large density drop occurs near the small clearance annular seal exit, which provides the swirl velocity increase in accordance with angular momentum conservation.
Book Synopsis Numerical and Experimental Evaluation of a New Low-leakage Labyrinth Seal by : D.L. Rhode
Download or read book Numerical and Experimental Evaluation of a New Low-leakage Labyrinth Seal written by D.L. Rhode and published by . This book was released on 1988 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Parameters Defining Flow Resistance and the Friction Factor Behavior in Liquid Annular Seals with Deliberately Roughened Surfaces by : Larry Alfonso Villasmil Urdaneta
Download or read book Parameters Defining Flow Resistance and the Friction Factor Behavior in Liquid Annular Seals with Deliberately Roughened Surfaces written by Larry Alfonso Villasmil Urdaneta and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Non-contacting annular seals are internal sealing devices used in rotating machinery, such as multistage centrifugal pumps and compressors. Their design affects both efficiency and rotor stability. Traditional plain and labyrinth seals are being replaced with stators containing different roughness patterns to reduce leakage and enhance rotor response. Several roughened seal experiments with liquid and air have produced leakage data indicating that the friction factor increases as the seal clearance is increased. Simplified models based on bulk flow theory and Moody's approach to characterize wall friction in pipes cannot explain this outcome. This research is an extension of a 2-D numerical analysis of flat plate experiments with water which found that friction factor of these surfaces is governed by the roughness' ability to develop high static pressures. An exhaustive 3-D numerical analysis of several experiments with liquid annular seals has been performed using a CFD code. Direct numerical simulations (DNS) of turbulent channel flow and smooth seals were replicated within 1% using Reynolds-averaged Navier-Stokes (RANS) equations and turbulence modeling. Similarly, measured groove seal leakage rates were reproduced within 2%. On the other hand, no turbulence model combination predicts the leakage in most 3-D pattern roughened seals with the same accuracy. Present results reproduce the friction factor "plateau" behavior predicted with the 2-D analysis and observed in the flat plate experiments. They also reproduce the friction-factor-to-clearance indifference behavior, the maximum friction factor observed in a specific roughness pattern size is independent of the actual clearance in a certain Reynolds number range, but clarify the role of the roughness length-to-clearance ratio and the actual roughness size in defining the friction-factor-to clearance proportionality. All simulations indicate that roughened surface area and roughness aspect ratios are the parameters defining the friction factor at a given seal clearance. The roughness pattern size, relevant in determining the friction-factor-to-clearance proportionality, plays a moderate role once the above cited ratios are defined. In any shape and size, shallow patterns arepredicted and observed to provide larger friction factors than deep patterns. Predictions also confirm limited experimental data showing that friction factor is affected by the mean flow orientation relative to the roughness pattern. Solving RANS equations is sufficient to model simple seal geometries but might not be enough to replicate turbulent flow in liquid annular seals with roughened surfaces.
