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van der Vooren, J. (author), Schippers, H. (author)
A thorough discussion of the mathematical modelling of unsteady transonic flow is presented. Starting from the Euler equations potential theory is derived and applied to the flow about a 2D airfoil. Motions considered include rigid body motions as well as deformations of the airfoil itself. The full-potential equation is formulated on...
report 1983
document
van der Wees, A.J. (author), van der Vooren, J. (author), Meelker, J.H. (author)
Two relaxation-algorithms and a number of restriction/prolongation-processes are compared within a non-linear FAS multi-grid research code. Paper focuses on the choice of relaxationalgorithm, which should be fast, robust (stable convergence for all local flow directions) and insensitive (good short wave damping for all possible mesh ratios). A...
report 1983
document
van der Vooren, J. (author), van der Wees, A.J. (author), Meelker, J.H. (author)
In the present document the pre-design will be presented of the system MATRICS (Multi-component Aircraft Transonic Inviscid Computation System). The system will be able to calculate the inviscid steady transonic flow about complex transport aircraft under cruise conditions; both jet-aircraft and propeller-aircraft can be simulated. As such the...
report 1985
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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
document
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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Boerstoel, J.W. (author), Veldman, A.E.P. (author), van der Vooren, J. (author), van der Wees, A.J. (author)
Current and mid-term developments in computational 3-D 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
document
van der Vooren, J. (author), Delil, A.A.M. (author), Sanderse, A. (author)
A new uniaxial model for a gas loaded variable conductance heat pipe (VCHP) is developed. This model takes into account the diffusion at the vapour-gas interface as well as the inertial effects of the moving vapour. Only steady-state conditions are considered. The generally accepted Edwards /Marcus model will be shown to be a first order...
report 1980
document
van der Vooren, J. (author)
A discussion is presented of an unsteady uniaxial theory for the description of transient phenomena in gas loaded variable conductance heat pipes. Flat front is recommended as a basis for calculations. To carry out these calculations, there should be devised so-called fully-conservative finite-difference schemes of the sort also used in the...
report 1980
document
van der Vooren, J. (author)
In studies concerning the sound transmitting properties of circular cylindrical shells the radial motions which propagate in the direction of the shell axis are of primary interest (ref 4). So-called coincidence occurs when the velocity of the sound waves along the cylinder equals the propagation speed of free travelling elastic flexural wavel...
report 1967
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van der Vooren, J. (author), Delil, A.A.M. (author)
A uniaxial model for the thermal performance of a variable conductance heat pipe (VCHP) has been developed at NLR. The model, so far, accounts for diffusion at the vapour/gas interface as well as for inertia! effects of the moving vapour, Calculations performed have shown that the diffusion effects are of minor importance in comparison with the...
report 1981
document
van der Vooren, J. (author)
report 1971
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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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van der Vooren, J. (author), van der Wees, . (author), Meelker, J.H. (author)
MATRICS is a system under development for the calculation of transonic (potential) flow about transport aircraft. The paper discusses the motivation for this development, as well as the basic concepts of the system. Details of the full potential flow solver, involving the newly developed ILU/SIP relaxation scheme, are given. A discussion on...
report 1986
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van der Vooren, J. (author), van der Wees, A.J. (author)
The mathematical background is described of a method that is currently being developed at NLR to calculated wave drag in transonic potential flow. The method is a generalization and extension of Garabedian's and McFadden's idea of determining wave drag by volume-integration of the artificial viscosity. The generalization of Garabedian's and...
report 1990
document
Labrujere, T.E. (author), Maarsingh, R.A. (author), van der Vooren, J. (author)
report 1972
document
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), Sanderse, A. (author)
A fully-conservative- finite difference algorithm is described to calculate the incompressible flow through a straight channel of varying rectangular cross section. Both the width and the height of the channel may vary independently. The algorithm has been used successfully in the design of the German-Dutch low speed wind tionel (DNW).
report 1977
document
van der Vooren, J. (author)
In dit memorandum zullen achtereenvolgens kort worden besproken: a. Het wiskundig model, waarop de methode is gebaseerd. b. De oplossing van dit model met behulp van een lijn-relaxatie/differentie methode. c. De stand van zaken per oktober 1975, geïllustreerd met enige voorbeelden van berekeningen. d. De noodzakelijke verdere ontwikkelingen.
report 1975
document
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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Posthuma de Boer, U. (author), Hameetman, G.J. (author), Heerema, F.J. (author), van der Vooren, J. (author)
Om haar taken doeltreffend te kunnen uitvoeren was in de zeventiger jaren voor het NLR een ver doorgevoerde centralisering nodig van funkties op de centrale computer in de Noordoostpolder. Deze centralisering werd mogelijk gemaakt door de opzet van een computernetwerk rondom deze centrale computer. Voor de jaren tachtig gelden de eisen, welke...
report 1980
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