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van den Berg, A.N. (author), Veerman, H.P.J. (author), Breeuwer, E. (author), Farnworth, R. (author)Prior to the operational implementation of EGNOS, the civil aviation community requires assurance with respect to the performance and safety of EGNOS-based operations. In the frame of the GNSS-1 Operational Validation (GOV) project, EUROCONTROL requested the development of a platform to be used for flight trials. In this context the Netherlands...report 2001
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ten Dam, A.A. (author), van den Berg, J.I. (author)The mathematical modelling and numerical simulation of a condenser is discussed. This mathematical model is part of the NLR approach to model and scale two-phase heat transport systems (for space). During a previous study the condensation length required for various gravity conditions, and working fluids has been investigated by means of...report 1993
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ten Dam, A.A. (author), van den Berg, J.I. (author)In this report the numerical simulation of a mathematical model of a condenser is discussed. This mathematical model of the NLR approach to model and scale two-phase heat transport systems. In this report the model of the condenser is reformulated to a model that is suitable for a numerical discussion. The results is a model that is represented...report 1992
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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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van den Berg, J.I. (author)In the development of mathematical simulation methods for engineering processes, it is essential to validate the mathematical models. Its results must be compared with results from other calculation methods or measurements. This is especially true in computational fluid dynamics (CFD). It is essential that an engineer developing mathematical...report 1987
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Groothuizen, R.J.P. (author), van den Berg, J.I. (author), van Leeuwen, W. (author)Design of robots is an iterative process. Therefore software tools for analysis of different concepts without the need to build hardware models are required. The software tool ROBDYN can be used for analysis of the dynamics properties of a robot. Main constituents are a dynamics algorithm and a facility for the preand postprocessing of data. The...report 1986
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van den Berg, B. (author)On the basis of a simple analysis of boundary layer properties it is argued that skin friction reduction in adverse-pressure-gradient (but attached) boundary layers does not necessarily leads to viscous drag reduction.report 1986
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van den Berg, B. (author), Bertelrud, A. (author)Measurement techniques in low-speed turbulent flows were discussed at the EUROMECH 202 Colloquium at NLR in Marknesse, The Netherlands, October 7-10, 1985. A total of 54 participants from 9 countries attended, and 38 papers were given in two sessions, each closed with a general discussion.report 1986
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van den Berg, B. (author)Three-dimensional shear layer experiments are discussed with a view to those developing calculation methods. The emphasis is on the selection of useful experiments for comparisons with calculations and the proper way to perform the comparisons. A review of more recent three-dimensional shear layer experiments is included.report 1986
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Humphreys, D.A. (author), van den Berg, B. (author), Krause, E. (author), Lindhout, J.P.F. (author)The results of several three-dimensional turbulent boundary layer calculations have been compared with each other and with experiment for a number of test cases. The calculation methods applied range from integral methods to field methods using a turbulence model based upon the Reynolds stress transport equations. The test cases comprise various...report 1985
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Oskam, B. (author), van den Berg, B. (author)The symposium demonstrated the importance of research in the area of mechanical high-lift systems for transport aircraft to improve the total performance of current transports. Computational techniques are shown to provide new tools for high-lift design. With regard to drag reduction by laminar flow control it is concluded that the information...report 1985
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- van den Berg, B. (author) report 1984
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- van Egmond, J.A. (author), van den Berg, B. (author) report 1984
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van den Berg, B. (author)The turbulence transport equations are reviewed. The role of the pressurestrain term is studied. It is shown that the pressure-strain term exactly cancels the production term when the Taylor hypotVjesis or frozen turbulence approximation holds. The consequences of this result foi[ the interpretation of the turbulence transport equations are...report 1984
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van den Berg, B. (author)The transport equations for the six turbulent stress tensor components are discussed, with particular emphasis on the terms containing turbulent pressure fluctuations. The conventional separation of the pressure fluctuation terms is argued. A more logical separation is proposed.report 1983
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- van den Berg, B. (author), van Egmond, J.A. (author) 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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Lindhout, J.P.F. (author), de Boer, E. (author), van den Berg, B. (author)A computational method is presented for threedimensional turbulent boundary layers. The turbulence model is a simple eddy-viscosity formulation. An hybrid difference scheme is used, which has the robustness of first order schemes and accuracy of second order schemes. The boundary layer is computed in the region of determinacy of the initial data...report 1982
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- van den Berg, B. (author) report 1982
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van den Berg, B. (author)The main results of the three-dimensional turbulent boundary layer experiments carried out up to now are discussed. The emphasis is on the direction of the measured turbulent shear stress, which generally differs from the direction of the velocity gradient. In a number of cases (but not all cases) the behaviour can be understood when assuming a...report 1982