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Buijsen, F.A. (author), Kassies, A. (author), Boerstoel, J.W. (author)The results of calculations of two and threedimensional flows on blocked grid domains consist of vast data collections with a simple, regular structure. The inspection of these results can only be done efficiently by graphical means, and by exploiting the regular structure of the data. There is a large similarity between the format of the...report 1988
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 Boerstoel, J.W. (author) report 1988
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Boerstoel, J.W. (author)In Eulerflow calculations based on cellcentered schemes, the number of equations required to determine the flowstate evaluation at grid points half a mesh outside the flow domain usually exceeds the number of boundarycondition equations provided by characteristic theory. Here, the required additional equations are obtained by a physically...report 1987
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Boerstoel, J.W. (author), Veldman, A.E.P. (author), van der Vooren, J. (author), van der Wees, A.J. (author)Current and midterm developments in computational 3D steady aerodynamics software at NLR, focusing on the efficient aerodynamic design of the next generation of transport aircraft, are surveyed on a global level. Following a brief review of the various levels of sophistication in physical flow modelling, and their relation to the aerodynamic...report 1986
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Boerstoel, J.W. (author)An analysis of various alternative approaches in grid generation is presented. A gridgeneration procedure for complex aircraft configurations could be based on a combination of three subprocesses, . decomposition of the flow domain into about 100 hexahedronal blocks, . trilineair transfinite interpolation to generate initial grid point...report 1986
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Boerstoel, J.W. (author)The technical concepts of a method for the generation of 3D blockstructured grids are presented. The generation process is decomposed in four more or less sequential steps. 1. Topological block decomposition. 2. Geometrical modeling of known and unknown coordinate functions. 3. Grid initialisation by multilinear transfinite interpolation. 4....report 1986
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Boerstoel, J.W. (author)Na inleidende opmerkingen betreffende de stateoftheart van het berekenen van stromingen op basis van de Euler vergelijkingen wordt voorgesteld rekenprogramma's te ontwikkelen voor de simulatie van propellor slipstroomeffecten over motorgondelvleugel configuraties. Verder zal aandacht worden geschonken aan de berekening van stromingen in het...report 1985
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Fray, J.M.J. (author), Slooff, J.W. (author), Boerstoel, J.W. (author), Kassies, A. (author)An engineering method for the design of airfoils having a prescribed pressure distribution in subsonic or transonic flow is described. The method is based on an iterative, "residualcorrection" type of procedure. In each iteration step, the difference between the current and a target pressure distributions (residual) is determined by means of a...report 1984
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Fray, J.M.J. (author), Slooff, J.W. (author), Boerstoel, J.W. (author), Kassies, A. (author)An engineering method for the design of airfoils having a prescribed pressure distribution in subsonic or transonic flow is described. The method is based on an iterative procedure of "residualcorrection" type. In each iteration step, the difference between a current and a target pressure distribution (residual) is determined by a fast (multi...report 1984
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 Boerstoel, J.W. (author) report 1983
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Boerstoel, J.W. (author)A survey of numerical methods for the calculation of inviscid Euler flows is presented. This survey has been prepared for AGAKD FDP WGOT: "Test cases for steady inviscid transonic or supersonic flows". The survey is augmented by a short assessment of the usefulness of the methods. For aerodynamic applications, the existing methods are in a...report 1983
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Wubs, F.W. (author), Boerstoel, J.W. (author), van der Wees, A.J. (author)An error analysis is presented of the numerical calculation of the steady flow on an infinite domain around a given airfoil by a domainsplitting (= zonal) method. This method combines a fully conservative finitedifference approximation on a finite domain around the airfoil with an approximate asymptotic solution outside this finite domain. The...report 1983
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Boerstoel, J.W. (author), Kassies, A. (author)A robust fastsolver for the calculation of transonic potential flows around lifting airfoils is presented. The solver is a combination of Newton iteration and CS (correction scheme) multigrid relaxation. This combination allows a simpler analysis of convergence properties than the PAS (full approximation storage) multigrid relaxation that is...report 1983
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Boerstoel, J.W. (author)TRAFS is a new fastsolver program for the calculation of steady subsonic and transonic inviscid flows around aerofoils. It uses a potentialflow model representing mass conservation in the flow. Potential users of TRAFS are given an impression of the user capabilities. These are illustrated by analyzing sixteen flow cases covering...report 1982
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Boerstoel, J.W. (author)The calculation of transonic flows with shocks with multigrid fastsolver algorithms is known to be not so efficient as in elliptic problems, because the appropriate treatment of shocks is a problem. As a first step to a solution, a few ideas concerning the design of finitedifference equations over shocks and the rapid calculation of such flows...report 1982
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Boerstoel, J.W. (author)The application of a combination of Newton iteration and multigrid line relaxation to transonic potentialflow calculations was investigated. Fully conservative potential flows around aerofoils were used as test problems. The multigrid process was used in each Newton iteration step to calculate correction potentials. It was found that the...report 1981
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Boerstoel, J.W. (author)The application of multigrid relaxation to transonic potentialflow 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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Boerstoel, J.W. (author)Within the scope of a study of efficient algortihms for the calculation of transonic potential flows, an interactive research computation system has . been developed, which permits numerical experimentation with a multigrid fast solver. This research system must be replaced by a production version having improved modularity. This concerns the...report 1981
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 Boerstoel, J.W. (author), Slooff, J.W. (author), van de Vooren, J. (author) report 1979
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Boerstoel, J.W. (author), Simons, J.L. (author)The twodimensional transonic smallperturbation equation is solved by a higherorder finite element method using a combination of a Galerkin orthogonalization procedure and a leastsquares method. It is shown that this higherorder method requires a nontrivial formulation of the discrete boundary conditions. The Galerkin orthogonalization...report 1978