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Qiu, Y. (author), Van Gijzen, M.B. (author), Van Wingerden, J. (author), Verhaegen, M. (author), Vuik, C. (author)This paper studies a new preconditioning technique for sparse systems arising from discretized partial differential equations (PDEs) in computational fluid dynamics (CFD), which exploit the multilevel sequentially semiseparable (MSSS) structure of the system matrix. MSSS matrix computations give a data-sparse way to approximate the LU...report 2013
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Romero-Valle, M.A. (author), Pisaroni, M. (author), Van Puyvelde, D. (author), Lahaye, D.J.P. (author), Sadi, R. (author)Rotary kilns are used in many industrial processes ranging from cement manufacturing to waste incineration. The operating conditions vary widely depending on the process. While there are many models available within the literature and industry, the wide range of operating conditions justifies further modeling work to improve the understanding of...report 2013
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Verwer, J. (author), Loeve, W. (author), Snijdoodt, E. (author), ten Dam, A. (author)In The Netherlands as a result of a national HPCN initiative a Foundation HPCN was established in 1995. The purpose of this Foundation is to stimulate structural and lasting cooperation of universities, technological institutes and industry in economically relevant applications of HPCN. Projects have been selected and since the beginning of 1996...report 1997
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van der Wees, A.J. (author), van den Berg, J.I. (author)NLR mainly performs applied scientific research for use in the aerospace industry. In many cases the product has the form of an information system for the design, production and usage of aerospace vehicles. Within this context, the mathematician contributes, in cooperation with specialists from other disciplines such as aerodynamics, structures,...report 1990
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Spekreijse, S.P. (author), Venis, A.C.J. (author)An efficient Roe-type flux-difference scheme for chemically reacting inviscid compressible flow in thermal equilibrium is presented. The numerical scheme is validated. Three well known chemical models are compared. The set of testcases concerned quasi one-dimensional hypersonic nozzle flows, with and without strong normal Shockwaves.report 1990
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Hoeijmakers, H.W.M. (author)The physical aspects, the mathematical modeling, the development and application of computational methods for the simulation of vertical flows are described. The high-Reynolds number vortex flows considered are assumed to be steady, sub-critical and such that the structure of the flow is well-ordered and consists of thin shear layers and slender...report 1989
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Hounjet, M.H.L. (author)A description is given of the method CAR88 for the calculation of steady and time-linearized unsteady subsonic and supersonic flow about complex 2-D and 3-D configurations. The method belongs to the category of the socalled panel methods. Results of applications in supersonic flow are shown which have been made to a 2-D oscillating flat plate, a...report 1988
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van den Dam, R.F. (author)The central issue discussed in this paper is how a designer may profit from the use of mathematical simulation and optimization techniques. These techniques can be useful tools to support the designer in solving his design problem. The place and the potential of these techniques in the design process, as well as their use by the designer, are...report 1985
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Chen, C.J. (author), Singh, K. (author)The use of second order closure turbulence model in predicting turbulent flows is known to be more successful than the classical mixing length model. However, it is found that if the turbulence constants are not altered or modified, the second order closure turbulence model is unable to predict satisfactorily f or some flows such as round jet...report 1985
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Koppenol, P.J. (author)A computational method for solving the 3D Euler equations is studied. The method is based upon an upwind flux-difference splitting scheme by Osher, exhibiting an implicit mechanism for numerical viscosity, in connection with an explicit time-marching finite-volume technique. The computer program is developed to run efficiently on both a scalar...report 1985
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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
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Smith, J. (author)The applicability of two-dimensional flexible solid wall test sections for three-dimensional testing is theoretically investigated for linearized subsonic flow. The method uses known interference velocity distributions along a targer line (derived from a method of images for this particular study). From these, wall shapes are calculated that...report 1984
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Slooff, J.W. (author)A discussion is given of the physical mechanisms governing the hydrodynamics of sailing yacht keels and the parameters that, through these mechanisms, determine keel performance. It is concluded that due to the presence of the free water surface optimum keel shapes differ from optimum shapes for aircraft wings, a fact that does not seem to have...report 1984
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de Bruin, A.C. (author)The three dimensional flow field around delta wings with leading-edge vortex flow can be computed with panel methods. However, secondary flow separation may occur on the leeward surface of the wing. The associated free vortex sheet can be modeled in the potential flow calculation method, if the location of the secondary separation is provided by...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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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)Examples are discussed of the application of computational methods in aerodynamic design problems involving interference. Amongst these are: subsonic wing-body, sting support, pylon-nacelle and pylon-store interference, high-lift devices, induced drag minimization through constrained optimization in the Treftz-plane and transonic wing-fuselage...report 1983
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van der Vooren, J. (author), van der Kolk, J.T. (author), Slooff, J.W. (author)A description will be presented of a computer program system that is being used for the prediction of aircraft steady aerodynamic characteristics. Properties of the system are described from two different viewpoints. One is that of the aerodynamic designer, who needs an information system to predict lift, moment and drag characteristics and to...report 1982
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Lindhout, J.P.F. (author), van den Berg, B. (author), Elsenaar, A. (author)At the workshop nine participants presented the results of their calculations for a practical test case. The test case deals with the 3D turbulent boundary layer development, including separation, on the root section of a swept wing. The employed calculation methods comprise 3D integral methods as well as field methods. A short description of...report 1981