ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Measured effect of step axial location on labyrinth seal leakage (1992)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: An advanced, finite volume code has been extensively used in a parametric design study of simple stepped seals, in order to ascertain a leakage-minimizing optimal design and test it, in conjunction with the baseline case of the wear-ring seal of a high pressure pump. It is found that a significant leakage effect arises from this shifting of the rotor and stator sealing surfaces; at extremely low rpm, a significant shaft speed effect occurs for the optimized design in some shaft locations.
    Keywords: MECHANICAL ENGINEERING
    Type: Journal of Propulsion and Power (ISSN 0748-4658); 8; 6; p. 1129, 1130.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    Effect of shaft rotation on the incompressible flow in a labyrinth seal (1990)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Keywords: MECHANICAL ENGINEERING
    Type: Journal of Propulsion and Power (ISSN 0748-4658); 6; 171-176
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Numerical and experimental evaluation of a new low-leakage labyrinth seal (1988)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: The effectiveness of a recently developed leakage model for evaluating new design features of most seals is demonstrated. A preliminary assessment of the present stator groove feature shows that it gives approximately a 20 percent leakage reduction with no shaft speed effects. Also, detailed distributions of predicted streamlines, axial velocity, relative pressure and turbulence energy enhance one's physical insight. In addition, the interesting measured effect of axial position of the rotor/stator pair on leakage rate and stator wall axial pressure distribution is examined.
    Keywords: MECHANICAL ENGINEERING
    Type: AIAA PAPER 88-2884
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Mean flowfields in axisymmetric combustor geometries with swirl (1983)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: (Previously cited in issue 06, p. 860, Accession no. A82-17824)
    Keywords: FLUID MECHANICS AND HEAT TRANSFER
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    A Computer Code for Swirling Turbulent Axisymmetric Recirculating Flows in Practical Isothermal Combustor Geometries (1982)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A primitive pressure-velocity variable finite difference computer code was developed to predict swirling recirculating inert turbulent flows in axisymmetric combustors in general, and for application to a specific idealized combustion chamber with sudden or gradual expansion. The technique involves a staggered grid system for axial and radial velocities, a line relaxation procedure for efficient solution of the equations, a two-equation k-epsilon turbulence model, a stairstep boundary representation of the expansion flow, and realistic accommodation of swirl effects. A user's manual, dealing with the computational problem, showing how the mathematical basis and computational scheme may be translated into a computer program is presented. A flow chart, FORTRAN IV listing, notes about various subroutines and a user's guide are supplied as an aid to prospective users of the code.
    Keywords: AIRCRAFT PROPULSION AND POWER
    Type: NASA-CR-3442
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Predicting Leakage in Labyrinth Seals (1985)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: Analytical and empirical methods evaluated. 264-page report presents comprehensive information on leakage in labyrinth seals. Summarizes previous analyses of leakage, reviews leakage tests conducted by authors and evaluates various analytical and experimental methods of determining leakage and discusses leakage prediction techniques.
    Keywords: MACHINERY
    Type: MFS-27051 , NASA Tech Briefs (ISSN 0145-319X); 9; 2; P. 149
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Mean flowfields in axisymmetric combustor geometries with swirl (1982)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: Six flowfield configurations are investigated with sidewall angles of 90 and 45 deg, and swirl vane angles of 0, 45, and 70 deg. It is found that central recirculation zones occur for the swirling flow cases investigated, which extend from the inlet to x/D = 1.7, where x is the axial polar coordinate, and D is the test section diameter. Five-hole pitot probe pressure measurements are used to determine time-mean velocities, and corresponding flow situations are predicted and compared to results of experimental data. Excellent agreement is found for the nonswirling flow, although poor agreement is found for swirling flow cases, especially near the inlet. The discrepancy is attributed to the lack of realism in the turbulence model, and/or to inaccurate specification of time-mean velocity and turbulence energy distributions at the inlet.
    Keywords: FLUID MECHANICS AND HEAT TRANSFER
    Type: AIAA PAPER 82-0177 , Aerospace Sciences Meeting; Jan 11, 1982 - Jan 14, 1982; Orlando, FL
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    On the prediction of swirling flowfields found in axisymmetric combustor geometries (1981)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: The paper reports research restricted to steady turbulence flow in axisymmetric geometries under low speed and nonreacting conditions. Numerical computations are performed for a basic two-dimensional axisymmetrical flow field similar to that found in a conventional gas turbine combustor. Calculations include a stairstep boundary representation of the expansion flow, a conventional k-epsilon turbulence model and realistic accomodation of swirl effects. A preliminary evaluation of the accuracy of computed flowfields is accomplished by comparisons with flow visualizations using neutrally-buoyant helium-filled soap bubbles as tracer particles. Comparisons of calculated results show good agreement, and it is found that a problem in swirling flows is the accuracy with which the sizes and shapes of the recirculation zones may be predicted, which may be attributed to the quality of the turbulence model.
    Keywords: AIRCRAFT PROPULSION AND POWER
    Type: In: Fluid mechanics of combustion systems; June 22, 23, 1981; Boulder, CO
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Effect of shaft rotation on the incompressible flow in a labyrinth seal (1987)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: The incompressible flow in a labyrinth seal at low leakage rates was computationally and experimentally investigated over a wide range of seal rotation rates. QUICK differencing was employed in the finite difference code to reduce the effects of false diffusion. The use of measured inlet boundary conditions for the axial and swirl velocity components and for the turbulent kinetic energy resulted in good agreement between velocity predictions and hot-film measurements. It was found that when the rotation rate is increased beyond a certain point, a second recirculation zone forms inside the seal cavity, altering the flow field in the cavity and resulting in a substantial increase in the pressure drop across it.
    Keywords: MECHANICAL ENGINEERING
    Type: Numerical methods in laminar and turbulent flow; Jul 06, 1987 - Jul 10, 1987; Montreal; Canada
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Design optimization and testing of a pump wear ring labyrinth seal (1988)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: It has been demonstrated that design optimization of labyrinth seals using the present numerical model is quite beneficial. The results shown include important, but previously unknown effects on the leakage rate, especially that of step height. Further, complete details are given of a very effective seal designed using this technique for the SSME high pressure hydrogen turbopump. Measurements using turbine flow meters revealed that the optimized configuration gives 67 percent leakage reduction over the original design. These measurements also reveal important leakage effects of the axial straining of the stator, which begins during pump start-up.
    Keywords: MECHANICAL ENGINEERING
    Type: AIAA PAPER 88-3693 , AIAA, ASME, SIAM, and APS, National Fluid Dynamics Congress; Jul 25, 1988 - Jul 28, 1988; Cincinnati, OH; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...