The response of aircraft to two-dimensional vertical turbulence

Equations for the response of an aircraft to two-dimensional vertical atmospheric turbulence have been derived, both for an aircraft regarded as a continuous system and for an aircraft split up into a number of panels. These equations have been applied to an aircraft model with two degrees of freedom of the size of the Fokker 100, respectively....

A Transonic model representation for two-dimensional wall interference assessment

2D wall interference assessment using "Calspan Pipes"

The applicability of a multi-velocity-component static pipe, proposed by CALSPAN ATC, for measuring boundary velocity vector distributions in behalf of wall interference assessment, has been explored in two-dimensional flow. Comparisons with alternative methods to derive the local flow angle from measured pipe pressures as well as analyses of...

Correction for wall-interference by means of a measured-boundary-condition method

A description is given of a method for the determination of global corrections for wall interference in both solid- and ventilated wall windtunnels, 2D as well as 3D. The method is based on the assumption that the flow velocity is known at a control surface surrounding the model and that the main part of the flow field may be considered...

A system for computer aided analysis and design of multi-element airfoils

A program system has been developed as a tool for interactive analysis and design of multi-element airfoils in incompressible viscous flow. A global description of the system is given. It involves the application of three computational methods, one for the analysis of viscous flow and one for the analysis of inviscid flow around multi-element...

Description and validation of the two-dimensional test setup for multiple airfoils in the pressurized wind tunnel HST

A description is given of the two-dimensional test setup in the pressurized wind tunnel HST of the NLR, for the testing of multiple airfoils at high Reynolds numbers. Results of the first tests with this setup are validated. For this validation a number of additional tests were performed in the HST as well as in the atmospheric wind tunnel HST 3...

A quasi-simultaneous calculation method for strongly interacting viscous flow around an infinite swept wing

An outline is presented of a new code, called VISIAN, for the analysis of aerodynamic flows with strong viscous-inviscid interaction. The code is based on the recently developed quasi-simultsuieous method for the calculation of strongly interacting boundary layers. The feasibility of this method has already been demonstrated liy means of a...

A method for determining 2D wall interference on an aerofoil from measured pressure distributions near the walls and on the model

A "measured-boundary-condition" method for determining 2D wall interference has been developed. It applies measured "wall" pressure distributions and a model representation to determine the 2D interference flow field associated with the presence of the test section walls. Special attention has been paid to the model representation. The...

A calculation method of the viscous flow around multi-component airfoils

The viscous flow around multi-component airfoils has been calculated by solving incompressible potential flow and boxindary layer problems iteratively. The potential flow problem is solved by a revised version of the 2D NLR panel method. A model transport equation of turbulent stress is employed to calculate the turbulent boundary layer. The...

Evaluation of Thing's method for the calculation of the lift discription on a wing in propulsive jets

The calculation method presented by Ting, Liu and Kleinstein in reference 3 has been subjected to an evaluation study, principally on the basis of experimental data obtained from special experiments on a half wing immersed in two jets. Very satisfactory results were found for the unflapped wing lying centrally within the jets. Both flap...

Aerodynamic data and off-design characteristics of the modified quasi-elliptical airfoil section NLR 7101

High subsonic and transonic effects in unsteady aerodynamics

Based on experimental observations an illustration is given of typical effects occiirring in high subsonic and transonic flow around oscillating airfoils and wings. It is shown that in this speed regime the unsteady airloads are influenced considerably by the interaction of the steady and unsteady flow fields. Moreover the periodical motion of...

Computations with the Garabedian and Korn program for two-dimensional transonic flows with embedded shocks

The report describes experiences with the Garabedian and Korn program for the computation of compressible potential flows, with or without shocks, both supercritical shockless flows and flows with shock waves. Computations for a number of quasi-elliptical aerofoils indicated that the conformal mapping procedure should be handled with care....

Experimental results around the design condition of a quasi-elliptical aerofoil modified for rear loading