Test Sections for Small Theoretical Wind-tunnel-boundary Interference on V/STOL Models

Test Sections for Small Theoretical Wind-tunnel-boundary Interference on V/STOL Models PDF Author: Ray H. Wright
Publisher:
ISBN:
Category : Interference (Aerodynamics)
Languages : en
Pages : 92

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Book Description
A wind-tunnel test section with closed upper wall, slotted side walls, and open lower boundary was found theoretically to produce zero tunnel-boundary lift interference on a small wing with horizontal wake mounted at the center of the test section. For this test section the variation of the interference with angle of the vortex wake behind a high-lift-coefficient model was not large. Because of the small slot widths required for zero interference and of the effects of boundary layer, the theory is regarded as unreliable for predicting the slot widths required; however, the variation of the interference with the slot width for widths somewhat greater than those needed for zero interference was found to be small. The interference in the region likely to be occupied by the tall of a model was investigated in some detail and was found to change with slot width and with wake angle more strongly than did the interference at the lifting element. A limited investigation of the lift interference in a test section with closed upper wall and slotted side and lower boundaries was made to obtain the theoretically indicated slot width required for zero lift interference at a center-mounted wing with the wake horizontal.

Test Sections for Small Theoretical Wind-tunnel-boundary Interference on V/STOL Models

Test Sections for Small Theoretical Wind-tunnel-boundary Interference on V/STOL Models PDF Author: Ray H. Wright
Publisher:
ISBN:
Category : Interference (Aerodynamics)
Languages : en
Pages : 92

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Book Description
A wind-tunnel test section with closed upper wall, slotted side walls, and open lower boundary was found theoretically to produce zero tunnel-boundary lift interference on a small wing with horizontal wake mounted at the center of the test section. For this test section the variation of the interference with angle of the vortex wake behind a high-lift-coefficient model was not large. Because of the small slot widths required for zero interference and of the effects of boundary layer, the theory is regarded as unreliable for predicting the slot widths required; however, the variation of the interference with the slot width for widths somewhat greater than those needed for zero interference was found to be small. The interference in the region likely to be occupied by the tall of a model was investigated in some detail and was found to change with slot width and with wake angle more strongly than did the interference at the lifting element. A limited investigation of the lift interference in a test section with closed upper wall and slotted side and lower boundaries was made to obtain the theoretically indicated slot width required for zero lift interference at a center-mounted wing with the wake horizontal.

Analytical Study of Ventilated Wind Tunnel Boundary Interference on V/STOL Models Including Wake Curvature and Decay Effects

Analytical Study of Ventilated Wind Tunnel Boundary Interference on V/STOL Models Including Wake Curvature and Decay Effects PDF Author: E. M. Kraft
Publisher:
ISBN:
Category : Short take-off and landing aircraft
Languages : en
Pages : 74

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Book Description
The wind tunnel boundary interference on a V/STOL model is calculated in a rectangular test section with solid vertical walls and ventilated (perforated or slotted) horizontal walls. The interference is found by applying the small perturbation theory of an incompressible fluid to the boundary value problem. The theory uses an image method in addition to Fourier transforms with an equivalent homogeneous boundary condition on the ventilated wall. The mathematical representation of the V/STOL model accounts for the curvature and decay of the wake. The assumption of a constant wake strength produces a paradox in that the maximum value of the interference factors increases as the initial jet velocity decreases. The most significant aspect of the analysis shows that nonlinear cross-flow effects at the tunnel boundary are important in the V/STOL case, and a quasi-linear approximation to these effects is introduced into the solution providing good agreement with experimental data.

Analytical Study of Ventilated Wind Tunnel Boundary Interference on V/STOL Models Including Wake Curvature and Decay Effects

Analytical Study of Ventilated Wind Tunnel Boundary Interference on V/STOL Models Including Wake Curvature and Decay Effects PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The wind tunnel boundary interference on a V/STOL model is calculated in a rectangular test section with solid vertical walls and ventilated (perforated or slotted) horizontal walls. The interference is found by applying the small perturbation theory of an incompressible fluid to the boundary value problem. The theory uses an image method in addition to Fourier transforms with an equivalent homogeneous boundary condition on the ventilated wall. The mathematical representation of the V/STOL model accounts for the curvature and decay of the wake. The assumption of a constant wake strength produces a paradox in that the maximum value of the interference factors increases as the initial jet velocity decreases. The most significant aspect of the analysis shows that nonlinear cross-flow effects at the tunnel boundary are important in the V/STOL case, and a quasi-linear approximation to these effects is introduced into the solution providing good agreement with experimental data.

Analytical Study of Ventilated Wind Tunnel Boundary Interference on V/STOL Models Including Wake Curvature and Decay Effects

Analytical Study of Ventilated Wind Tunnel Boundary Interference on V/STOL Models Including Wake Curvature and Decay Effects PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The wind tunnel boundary interference on a V/STOL model is calculated in a rectangular test section with solid vertical walls and ventilated (perforated or slotted) horizontal walls. The interference is found by applying the small perturbation theory of an incompressible fluid to the boundary value problem. The theory uses an image method in addition to Fourier transforms with an equivalent homogeneous boundary condition on the ventilated wall. The mathematical representation of the V/STOL model accounts for the curvature and decay of the wake. The assumption of a constant wake strength produces a paradox in that the maximum value of the interference factors increases as the initial jet velocity decreases. The most significant aspect of the analysis shows that nonlinear cross-flow effects at the tunnel boundary are important in the V/STOL case, and a quasi-linear approximation to these effects is introduced into the solution providing good agreement with experimental data.

Wind Tunnel Wall Interference in V/STOL and High Lift Testing: A Selected, Annotated Bibliography

Wind Tunnel Wall Interference in V/STOL and High Lift Testing: A Selected, Annotated Bibliography PDF Author: Marie H. Tuttle
Publisher:
ISBN:
Category :
Languages : en
Pages : 60

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Book Description


Wind Tunnel Boundary Interference on a V/STOL Model

Wind Tunnel Boundary Interference on a V/STOL Model PDF Author: Ching-Fang Lo
Publisher:
ISBN:
Category : Lift (Aerodynamics)
Languages : en
Pages : 10

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Book Description


Wind-tunnel Testing of VTOL and STOL Aircraft

Wind-tunnel Testing of VTOL and STOL Aircraft PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 86

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Book Description


Theoretical Study of Conditions Limiting V/STOL Testing in Wind Tunnels with Solid Floor

Theoretical Study of Conditions Limiting V/STOL Testing in Wind Tunnels with Solid Floor PDF Author: Harry H. Heyson
Publisher:
ISBN:
Category : Short take-off and landing aircraft
Languages : en
Pages : 340

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Book Description
Under sufficiently large wake deflections, the forward portion of the wake is found to flow forward along the floor leading to a vortex pattern which results in Rae's limits (Journal of Aircraft, May-June 1967). Although wind-tunnel data cannot normally be corrected successfully beyond these limits, it may be possible to obtain ground-effect data for conditions more severe than those implied by Rae.

Linearized Theory of Wind-tunnel Jet-boundary Corrections and Ground Effect for Vtol-Stol Aircraft

Linearized Theory of Wind-tunnel Jet-boundary Corrections and Ground Effect for Vtol-Stol Aircraft PDF Author: Harry H. Heyson
Publisher:
ISBN:
Category : Helicopters
Languages : en
Pages : 280

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Book Description


Monthly Catalog of United States Government Publications

Monthly Catalog of United States Government Publications PDF Author: United States. Superintendent of Documents
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages :

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Book Description
February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index