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
    On wake vortex alleviation (1975)
    In:  CASI
    Details
    Publication Date: 2006-01-11
    Description: Research within NASA relating to the nature of lift-induced vortex wakes behind large aircraft and the means whereby the hazard they represent to smaller aircraft can be alleviated is reviewed. The research, carried out in ground based facilities and in flight shows that more rapid dispersion of the wake can be effected by several means and that the modification of span-loading by appropriate flap deflection holds promise of early practical application.
    Keywords: AERODYNAMICS
    Type: NASA/Univ. Conf. on Aeron.; p 143-168
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    Interaction of a turbulent vortex with a lifting surface (1985)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: The impulsive noise due to blade-vortex-interaction is analyzing in the time domain for the extreme case when the blade cuts through the center of the vortex core with the assumptions of no distortion of the vortex path or of the vortex core. An analytical turbulent vortex core model, described in terms of the tip aerodynamic parameters, is used and its effects on the unsteady loading and maximum acoustic pressure during the interaction are determined.
    Keywords: AERODYNAMICS
    Type: Anal. of Selected Probl. Involving Vortical Flows; p 18-28
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    On the structure of the turbulent vortex (1985)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: The trailing vortex generated by a lifting surface, the structure of its turbulent core and the influence of axial flow within the vortex on its initial persistence and on its subsequent decay are described. Similarity solutions of the turbulent diffusion equation are given in closed form and results are expressed in sufficiently simple terms that the influence of the lifting surface parameters on the length of persistence and the rate of decay of the vortex can be evaluated.
    Keywords: AERODYNAMICS
    Type: Anal. of Selected Probl. Involving Vortical Flows; p 6-17
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Persistence and decay of wake vorticity (1976)
    In:  CASI
    Details
    Publication Date: 2017-10-02
    Description: Some recent research relating to the nature of the lift-induced vortex wakes behind large aircraft was reviewed and the scaling laws that permit a comparison of results from ground facilities with those from flight test were provided. The maximum rotational velocities in the wake are shown to depend on a span loading shape parameter and on a characteristic length of persistence behind the aircraft. The effects of Reynolds number are also shown.
    Keywords: AERODYNAMICS
    Type: AGARD Flight(Ground Testing Fac. Correlation; 10 p
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    A theory for lateral wing-tip blowing (1985)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The concept of lateral blowing consists in utilizing thin jets of air, which are ejected in the spanwise direction from slots at the tips of straight and swept wings, or along the leading edges of delta wings, to generate aerodynamic forces without the assistance of deflecting solid surfaces. For weak intensities of blowing the so-generated forces could be used for roll and lateral control of aircraft. In this work a theory for this concept as applied to straight wings is presented, revealing the analytical relationship between blowing and aerodynamic forces. The approach is based on perturbing the span of an elliptically loaded wing. Scaling laws involving blowing intensity, aspect ratio, and angle of attack are derived and compared with experiments. It is concluded that this concept has potential as a novel roll and lateral control device.
    Keywords: AERODYNAMICS
    Type: NASA-CR-176931 , NAS 1.26:176931 , JIAA-TR-60
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Theoretical studies on flapped delta wings (1988)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: The effects of leading edge flaps on the aerodynamic characteristics of a low aspect-ratio delta wing are studied theoretically. As an extension of the classical crossflow plane analysis and in order to include separated shear layers, an analogy between three dimensional steady conical and two dimensional unsteady self-similar flows is explored. This analogy provides a simple steady-unsteady relationship. The criteria for the validity of the steady-unsteady analogy are also examined. Two different theoretical techniques are used to represent the separated shear layers based on the steady-unsteady analogy, neglecting the trailing edge effect. In the first approach, each vortex system is represented by a pair of concentrated vortices connected to the separation points by straight feeding sheets. In the second approach, the vortex cloud method is adopted for simulating the flow field in the crossflow plane. The separated shear layers are replaced with a cloud of discrete vortices and the boundary element method is employed to represent the wing trace by a vorticity distribution. A simple merging scheme is used to model the core region of the vortical flow as a single vortex by imposing a restriction on the shear layer rotation angle. The results are compared with experiments and with results from 3-D panel calculations.
    Keywords: AERODYNAMICS
    Type: NASA-CR-184795 , NAS 1.26:184795 , JIAA-TR-85
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Analysis of selected problems involving vortical flows (1985)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Three selected problems involving vortical flows are analyzed and discussed including: the trailing vortex behind a wing; rotor blade-vortex interaction; and the leading edge vortex on a flat plate.
    Keywords: AERODYNAMICS
    Type: NASA-CR-177347 , NAS 1.26:177347
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    An experimental investigation of straight and curved annular wall jets (1987)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Accurate turbulence measurements taken in wall jet flows are difficult to obtain, due to high intensity turbulence and problems in achieving two-dimensionality. The problem is compounded when streamwise curvature of the flow is introduced, since the jet entrainment and turbulence levels are greatly increased over the equivalent planar values. In this experiment, two-dimensional straight and curved incompressible wall jet flows are simulated by having a jet blow axially over a cylinder. Hot wire measurements and some Laser Doppler Velocimetry measurements are presented for straight and curved wall jet flows. The results for the straight wall showed good agreement between the annular flow data and the rectangular data taken by previous researchers. For the jets with streamwise curvature, there was agreement between the annular and corresponding rectangular jets for the flow region closest to the slot exit. An integral analysis was used as a simple technique to interpret the experimental results. Integral momentum calculations were performed for both straight and curved annular and two dimensional wall jets. The results of the calculation were used to identify transverse curvature parameters and to predict the values of those parameters which would delineate the region where the annular flow can satisfactorily simulate two dimensional flow.
    Keywords: AERODYNAMICS
    Type: NASA-CR-182546 , NAS 1.26:182546 , JIAA-TR-79
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    A numerical and experimental study of tangential jet blowing applied to bodies at high angles of attack (1991)
    In:  Other Sources
    Details
    Publication Date: 2019-07-27
    Description: The effects of tangential jet blowing on the vortical structures developing about the fuselage of a missile or aircraft at high angle of attack are investigated numerically and experimentally. Computations are carried out for fully laminar and fully turbulent flows, and the results are compared with flow visualization data. It is shown that turbulent computations are more accurate in describing the flow behavior. The actuator plane method is shown to be sufficiently accurate in modeling the essential flow physics of a tangential jet.
    Keywords: AERODYNAMICS
    Type: AIAA PAPER 91-3253 , AIAA Applied Aerodynamics Conference; Sept. 23-25, 1991; Baltimore, MD; United States
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Viscous-inviscid aerodynamic analysis of two-dimensional thrust augmentors (1984)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: A theory for the computation of two-dimensional thrust augmentor performance is developed. The flow field is assumed to be incompressible, of uniform density and statistically steady. The flow in and around the augmentor is assumed to consist of an outer, inviscid part and an inner, viscous part. The outer field is calculated analytically and then matched with the inner, viscous field, which is computed by means of integral methods. This form of analysis leads to a simple and economical approach, particularly useful for conducting parametric studies. The theoretical results are compared with recently acquired experimental data.
    Keywords: AERODYNAMICS
    Type: NASA-CR-177321 , NAS 1.26:177321
    Format: application/pdf
    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...