Experimental Investigation of the Pressure Distribution about a Yawed Circular Cylinder in the Critical Reynolds Number Range
Experimental Investigation of the Pressure Distribution about a Yawed Circular Cylinder in the Critical Reynolds Number Range

Author: William J. Bursnall

Publisher:

Published: 1951

Total Pages: 34

ISBN-13:

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An experimental investigation was made of the pressure distribution about a circular cylinder at various angles of yaw. The results indicate that the flow and force characteristics in the range of Reynolds number based on the normal velocity component near and above critical cannot be determined only by the component of flow normal to the cylinder axis. Localized regions of laminar separation which were present in the 0 degrees yaw case in the supercritical Reynolds number range became less distinct as the yaw angle was increased and completely disappeared for yaw angles from 45 and 60 degrees.

An Experimental Investigation on the Flow Around a Circular Cylinder in the First Critical Subregion
An Experimental Investigation on the Flow Around a Circular Cylinder in the First Critical Subregion

Author: Hyun Jin Kim

Publisher:

Published: 1986

Total Pages: 506

ISBN-13:

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An experimental investigation has been carried out on the flow transitions around a smooth circular cylinder in the initial stage of the critical Reynolds number region, where drag coefficient starts to decrease. In this Reynolds number region, intermitent reattachment of the separated boundary layer was found, while only initial separation position excursion was observed in the subcritical region. Large spanwise variations in the surface pressure and wake velocity observed in the first critical subregion were associated with local wake width pulsations caused by spanwise phase variations in the unsteady flow reattachment.

Aerodynamic Characteristics of Vehicle Bodies at Crosswind Conditions in Ground Proximity
Aerodynamic Characteristics of Vehicle Bodies at Crosswind Conditions in Ground Proximity

Author: Kalman J. Grunwald

Publisher:

Published: 1970

Total Pages: 148

ISBN-13:

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A series of force tests was conducted on unpowered, high-speed ground-vehicle model configurations to provide information on shapes of this type very near the ground. Of particular interest were the crosswind effects on the aerodynamic forces and moments of the six models tested. These tests were conducted over the moving-belt ground plane in the 17-foot (5.18-m) test section of the Langley 300-MPH 7-by 10-foot tunnel at free-stream dynamic pressure values of 10 lb/ft2 (478.8 N/m2). The results indicate that the half-circle configuration is desirable because of the low rolling moments it experienced; however, it did have higher lift values than the other configurations and, from a utility standpoint, could be impractical. The half-circle configurations with extended sides may make good compromise configurations. All the ground-simulation techniques employed -moving ground belt, fixed ground belt, and image model -gave reasonable representations of the overall aerodynamic trends.

Method of Matching Components and Predicting Performance of a Turbine-propeller Engine
Method of Matching Components and Predicting Performance of a Turbine-propeller Engine

Author: Alois T. Sutor

Publisher:

Published: 1951

Total Pages: 706

ISBN-13:

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Analytical expressions are derived to show the geometric, thermodynamic, and aerodynamic relations among compressor, turbine, and exhaust nozzle for a gas-turbine engine. For a known compressor performance map, a matching method is described to show some of the design compromises that must be made when the components are to be combined into a turbine-propeller engine. A method of predicting engine performance for a range of operating conditions from known component maps is presented. An illustrative example of the matching method and the performance analysis is presented, showing some of the practical limitations of engine operation.

A Method for Calculating the Subsonic Steady-state Loading on an Airplane with a Wing of Arbitrary Plan Form and Stiffness
A Method for Calculating the Subsonic Steady-state Loading on an Airplane with a Wing of Arbitrary Plan Form and Stiffness

Author: W. L. Gray

Publisher:

Published: 1953

Total Pages: 704

ISBN-13:

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A method for computing the steady-state span load distribution on an elastic airplane wing for specified airplane weights and load factors is given. The method is based on a modification of the Weissinger L-method and applies at subcritical Mach numbers. It includes the effects of external stores and fuselage on the spanwise loading. Modifications are outlined for treating tail-boom and tailless airplane configurations and for calculating the divergence dynamic pressure of a swept wing with a large external store. A method is also outlined for reducing wind-tunnel data to obtain effective aerodynamic coefficients which are free of model flexibility effects. The effects of Mach number can readily be evaluated from the aerodynamic coefficients thus obtained.