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Piers, W.J. (author), Slooff, J.W. (author)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...report 1972
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- Zwaaneveld, J. (author), van Egmond, J.A. (author) report 1972
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Smith, J. (author)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....report 1974
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Tijdeman, H. (author)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...report 1975
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- Zwaaneveld, J. (author) report 1976
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Labrujere, T.E. (author)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...report 1976
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Boerstoel, J.W. (author)In this study, an algorithm for the computational design of supercritical shock-free aerofoils is developed and analyzed with hodograph theory. Such an algorithm may be based on the combination of two approaches for the construction of solutions of the flow equations for shock-free transonic flow. In the first approach, such solutions are...report 1977
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Tijdeman, H. (author)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...report 1977
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van Egmond, J.A. (author), Rozendal, D. (author)The design and experimental verification of a thick (18 %), shock free airfoil is described. The design was performed, using the NLR hodograph theory for transonic airfoil design. The airfoil was experimentally investigated in the NLR Pilot tunnel.report 1978
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Houwink, R. (author), van der Vooren, J. (author)Paper presented at AIAA 12th Fluid and Plasma Dynamics Conference held in Williamsburg, Virginia, 23-26 July 1979. Using an improved version of the NASA Ames code LTRAN2, unsteady airloads were computed for a flat plate and a lifting transonic NACA 6k A006 airfoil, for harmonic pitch and control surface motions at reduced frequencies based on...report 1979
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van der Vooren, J. (author), Huizing, G.H. (author)A method is discussed for the calculation of inviscid transonic flow about thin airfoils in moderately slow unsteady motion. It is an extension of a method which was developed by Ballhaus and Goorjian of NASA Ames and which is applicable for strictly slow unsteady motions only. The modifications involve extra unsteady terms in the boundary...report 1980
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Oskam, B. (author)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...report 1980
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Vaatstra, W. (author), Veldman, A.E.P. (author), van der Vooren, J. (author)The method of Glowinski, Periaux and Pironneau for the calculation of transonic flow, which is based on the constrained minimization of a cost function, is critically evaluated for a case in which the transonic small perturbation equation is used. The resulting minimization problem is discretized in finite element form and solved using a...report 1980
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van der Vooren, J. (author), Huizing, G.H. (author), van Essen, A. (author)A calculation method, based upon transonic small perturbation theory, is presented for the transonic flow about a semi-wing. The influence of a body can be simulated by prescribing appropriate transverse velocities in a vertical plane through the wing root. Due to the small perturbation assumption the wing should be thin and have little dihedral...report 1981
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Houwink, R. (author)An outline is given of a first version of the computer programme LTRAFV for coupled unsteady transonic flow/turbxilent boundary layer computations. It is a combination of the LTRAN2-NLR programme and the lagentrainment method of Green. A comparison is made of theoretical and experimental results for the NACA64A006 airfoil with oscillating flap...report 1981
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Boerstoel, J.W. (author)The application of multigrid relaxation to transonic potential-flow calculation was investigated. Fully conservative potential flows around aerofoils were taken as test problems. The solution algorithm was based on Newton iteration. In each Newton iteration step, multigrid relaxation was used to calculate correction potentials. It was found that...report 1981
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Vogelaar, H.L.J. (author)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...report 1983
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van Egmond, J.A. (author), van den Berg, B. (author), Labrujere, T.E. (author)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...report 1983
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Labruijere, T.E. (author)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...report 1983
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Slooff, J.W. (author)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,...report 1984