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
Filter
Collection
Keywords
Publisher
Years
  • 1
    facet.materialart.
    Unknown
    Phase Space Boundary Conditions and Quantum Device Transport (1998)
    Hindawi
    Details
    Publication Date: 1998-01-01
    Description: Device-device interaction is described within the framework of the quantum Liouville equation. Approximations to treating this interaction, within the framework of alterations to phase space boundary conditions, are illustrated.
    Print ISSN: 1065-514X
    Electronic ISSN: 1563-5171
    Topics: Electrical Engineering, Measurement and Control Technology
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    A linear aerodynamic analysis for unsteady transonic cascades (1984)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A potential flow analysis to predict unsteady airloads produced by the vibrations of turbomachinery blades operating at transonic Mach numbers is presented. The unsteady aerodynamic model includes the effects of blade geometry, finite mean pressure variation across the blade row, high frequency blade motion, and shock motion within the framework of a linearized, frequency domain formulation. The unsteady equations are solved implicit, least squares, finite difference approximation which is applicable on arbitrary grids. A numerical solution for the entire unsteady field is determined by matching a solution determined on a rectilinear type cascade mesh, which covers an extended blade passage region, to a solution determined on a detailed polar type local mesh, which covers and extends well beyond the supersonic region(s) adjacent to a blade surface. Cascades of double circular arc and flat plate blades demonstrate the unsteady analysis, and partially illustrate the effects of blade geometry, inlet Mach number, blade vibration frequency and shock motion on unsteady response.
    Keywords: AERODYNAMICS
    Type: NASA-CR-3833 , E-2202 , NAS 1.26:3833 , R84-956393-8
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Development of an unsteady aerodynamic analysis for finite-deflection subsonic cascades (1981)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: An unsteady potential flow analysis, which accounts for the effects of blade geometry and steady turning, was developed to predict aerodynamic forces and moments associated with free vibration or flutter phenomena in the fan, compressor, or turbine stages of modern jet engines. Based on the assumption of small amplitude blade motions, the unsteady flow is governed by linear equations with variable coefficients which depend on the underlying steady low. These equations were approximated using difference expressions determined from an implicit least squares development and applicable on arbitrary grids. The resulting linear system of algebraic equations is block tridiagonal, which permits an efficient, direct (i.e., noniterative) solution. The solution procedure was extended to treat blades with rounded or blunt edges at incidence relative to the inlet flow.
    Keywords: AERODYNAMICS
    Type: NASA-CR-3455 , R81-914777-7
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    A linearized unsteady aerodynamic analysis for transonic cascades (1984)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: The unsteady airloads generated by the vibrations of turbomachine blades operating at transonic Mach numbers are predicted by a linearized potential flow analysis whose unsteady aerodynamics model encompasses the effects of blade geometry, nonzero mean pressure variation across the blade row, high frequency blade motion, and shock motion, all within the framework of a linearized frequency-domain formulation. A numerical solution for the entire unsteady flow field is determined by matching a solution covering an extended blade passage region to another covering, and extending beyond, the supersonic region(s) adjacent to a blade surface. Results are given for cascades of double circular arc and flat plate blades, in order to demonstrate the unsteady analysis and to partially illustrate the effects of blade geometry, inlet Mach number, vibration frequency and shock motion on unsteady response.
    Keywords: AERODYNAMICS
    Type: Journal of Fluid Mechanics (ISSN 0022-1120); 149; 403-429
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Applications of alternating direction methods to mildly nonlinear problems (1968)
    In:  CASI
    Details
    Publication Date: 2019-06-27
    Description: Alternating direction methods for solving mildly nonlinear equations, and iterative techniques for approximating solution
    Keywords: MATHEMATICS
    Type: NASA-CR-101121 , TR-68-83
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Development of a linear unsteady aerodynamic analysis for finite-deflection subsonic cascades (1981)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: A linear unsteady potential flow analysis, which accounts for the effects of blade geometry and steady turning, is being developed to predict the aerodynamic response to blade vibrations in the fan, compressor or turbine stages of modern jet engines. In previous work numerical solutions were restricted to cascades of sharp-edged blades aligned with the mean flow. Under the present effort the solution procedure has been extended to treat blades with rounded or blunt edges. As part of this effort an analytical model-problem study has been conducted to clarify the behavior of first-order perturbation solutions in the vicinity of airfoil edges. Further, a numerical approximation using concepts from singular perturbation theory has been developed to resolve the unsteady boundary value problem for cascades of blunt leading-edged blades. Numerical results for NACA 0012 cascades, including detailed results in the vicinity of a blade leading edge, are presented and evaluated.
    Keywords: AERODYNAMICS
    Type: AIAA PAPER 81-1290 , Fluid and Plasma Dynamics Conference; Jun 23, 1981 - Jun 25, 1981; Palo Alto, CA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Subsonic flow past an oscillating cascade with steady blade loading - Basic formulation (1975)
    In:  Other Sources
    Details
    Publication Date: 2019-07-13
    Description: A nonlinear boundary value problem governing the subsonic flow in a single, extended, blade passage region of a high-deflection, two dimensional, oscillating cascade is derived. The blades are assumed to be undergoing identical harmonic motions of small amplitude with constant phase angle between the motion of adjacent blades. An asymptotic perturbation approach is used to determine the velocity potential. This formulation can be used in the numerical determination of unsteady potential and thus the unsteady aerodynamic force and moment under various combinations of cascade and flow parameters.
    Keywords: AERODYNAMICS
    Type: Unsteady aerodynamics; Mar 18, 1975 - Mar 20, 1975; Tucson, AZ
    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...