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 survey of computational methods for subsonic and transonic aerodynamic design

An overview is provided of computational methods that can be used in solving the design problem of aerodynamics; i.e. the problem of finding the detailed shape of (parts of) configurations of which the gross geometric characteristics have already been determined in a preliminary, overall design process, and that, subject to certain constraints,...

Application of a constrained inverse method in the aerodynamic design of a low speed wing-slat configuration

At NLR a system for the computational design on multi-element airfoil has been developed. This design system solves the inverse aerodynamic problem in an approximate way. A priori specified aerodynamic requirements (surface pressure distribution) and geometric requirements are minimized in a least-squares way, introducing weight factors to...

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...

Investigations of the transonic flow around oscillating airfoils

Exploratory wind-tunnel experiments in high-subsonic and transonic flow on a conventional airfoil with oscillating flap and a supercritical airfoil oscillating in pitch are described. In the analysis of the experimental results, emphasis is placed upon the typical aspects of transonic flow, namely the interaction between the steady and unsteady...

Airfoil design by the method of singularities via parametric optimization of a geometrically constrained least squares object function

The present report describes a method for the design of airfoils in incompressible flow which, subject to geometrical constraints generate approximately a given distribution of the pressure coefficient along the projection of the airfoil chord on an axis parallel to the onset flow. The flow is simulated by means of a distribution of...

Calculation of the displacement effect in two-dimensional subsonic attached flow around aerofoils: examples of calculations using measured displacement thicknesses

Using measured displacement thicknesses the classical displacement effect on lift and pressure distribution has been calculated for a number of aerofoils in viscous attached flow. For this purpose the displacement concept boundary condition (in its "leak flow" form) has been incorporated in a potential flow calculation method that uses a...