Searched for: subject%3A%22computer%255C+programs%22
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de Pagter, P.J. (author), Renes, J.J. (author)
This report describes the results of a feasibility study on image data compression using spline approximation and image segmentation, with emphasis on earth observation applications. The main subjects dealt with, are: the data compression method, implementation aspects, the test software and test results. It appears that a reduction factor of 5...
report 1985
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Daniels, H.A.M. (author)
In this paper the CAD system DESTIP is described. DESTIP is developed at the NLR for designing compression panels in wing box structures. Application of the system yields optimal panels in the sense that they meet all the requirements imposed by the designer and have minimum weight per unit width. Weight reductions ranging from 0 to 10% have...
report 1985
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Pietersen, O.B.M. (author), Klinker, F. (author), Roefs, H.F.A. (author), Lucas, A.M.G.M. (author)
report 1984
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van der Linden, H.H. (author)
The GARTEUR Group of Responsables for Structures and Materials identified the need for an evaluation of fatigue crack propagation models. This resulted in a collaborative GARTEUR activity in which 13 variations of the F-27 transport spectrum were evaluated by 7 institutes and companies using in total 13 crack propagation prediction methods and...
report 1983
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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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Rienstra, S.W. (author)
A study is made of sound propagation through axially varying ducts with mean flow. Several analytical and numerical approaches are considered, and discussed with respect to their possibilities and limitations. Two new analytical theories, relevant for low and for high frequencies, are worked out in some detail. A fortuitously available *)...
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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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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Best, M.R. (author)
In NLR TR 82075 U, a method has been developed to reconstruct the flight-path of a symmetric flight, by representing this path by a set of splines. In the present report, the same method is being applied to a three-dimensional flight over a rotating earth. Preliminary results are comparable in accuracy and computing time to the Kalman (Square...
report 1983
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van Popta, R.G. (author)
Since mid 1982, the Royal Netherlands Meteorological Institute KNMI has to its possession a ground station (KOSMOSS), which receives and processes high resolution imagery, acquired from Tiros-N type weather satellites. To determine the weather positions in the images, the ground station is equipped with the capability to superpose, in real time,...
report 1983
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Vlieger, H. (author)
This report presents results of residual strength calculations, carried out on cracked panel configurations of various designs and provided with bonded stiffeners. The calculations were carried out using the computer program BOND. The results of these calculations are compared with results of residual strength tests, performed on panels of...
report 1983
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Loeve, W. (author), van den Dam, R.F. (author)
The NLR in the Netherlands renders scientific support and technical assistance for the design and operation of aircraft and spacecraft. The approach of NLR can be characterized by integration of experimental and theoretical investigations. For this an integrated computer and terminal network has been developed that links both NLR laboratory...
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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Fokkema, J.T. (author), Van Leuken, T.G.R. (author)
conference paper 1983
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van den Dam, R.F. (author)
An interactive computer program system has been developed which provides induced-drag analysis, optimization and configuration-design capabilities. The program system employs subsonic far-field (Trefftzplane) analysis, and novel mathematical formulations of the constrained optimization problems which are based on calculus of variations. The...
report 1982
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Dekker, G.J. (author)
Modern commercial transport aircraft contain digital avionics systems for more and more safety critical functions. The reliability and safety of those new systems depend on the hardware reliability and on the reliability of the embedded software. In this report, an overview is given of available methods and techniques to develop reliable...
report 1982
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Terpstra, A.P. (author), van den Dam, R.F. (author), van Woerkom, P.T.L.M. (author), Zwartbol, T. (author)
This document describes two computer programs developed during a study of the application of modern control techniques in the area of spacecraft attitude control. Theory and simulation results are described in part I of this report. In part II a general overview of the tasks of the simulation program is presented, and program design aspects are...
report 1982
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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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van der Laan, J.M. (author)
A measuring system is described for detection and analyses of aircraft wake vortices in the approach zone of a runway. This system consists of propeller anemometers, a data-acquisition unit, a quick-look monitor and a NOVA minicomputer with a real-time vortex detection program. A short description of aircraft wake vortices is also given. Some...
report 1982
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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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