Evaluation of a multigrid method for the reduction of the computational time of SWAN

The spectral wind wave model SWAN plays a key role in the estimation of the Hydraulic Boundary Conditions (HBC) for the primary sea defences of the Netherlands. Since some uncertainty remains with respect to the reliability of SWAN for application to the geographically complex area of the Wadden Sea, a number of activities have been initiated...

Architecture and construction principles for Computational Fluid Dynamics software for engineering in industry

For flow simulation around (parts of) aerospace vehicles, aerospace industry needs CFD software. For users in industry, not only the functionality of the software is relevant. Timely availability and cost of the first version and later versions are other relevant factors. These factors are represented in the software characteristics timeliness,...

An interface element for modelling the onset and growth of mixed-mode cracking in aluminium and fibre metal laminates

Demonstration of an automated CFD system for three-dimensional flow simulations

In this paper the capabilities of an automated CFD system which is currently available at NLR are demonstrated. Transonic flow around the AS28G wing/body configuration and hypersonic flow through a generic three-dimensional mixed-compression airbreathing inlet are simulated. An assessment of the level of automation of the current CFD-system is...

Structured parallelization of a multi-block Navier-Stokes solver targeting distributed memory platforms

SOLEQS is a sequential three-dimensional multi-block multi-zone compressible Navier-Stokes solver, produced by NLR. In this paper is described how this large-scale application code in the order of 120,000 lines can be parallelized towards different computing platforms in a structured and manageable way. This paralellization is done step-wise,...

Numerical simulation of leading-edge vortex flow

An analysis is presented of results of a computational method to simulate the steady compressible vortical type of flow around a 65-deg sharp-edged cropped delta wing. The discussion emphasizes some more fundamental aspects of the numerical simulation such as the separation of the flow, the structure of the leading-edge vortex core and the flow...

Hyperbolic grid generation with BEM source terms

A method is presented for the generation of 0-type grids about transverse cross-sections of transport type aircraft. The method combines a hyperbolic grid generation scheme with source terms obtained with a boundary element method in such a way that 0-type grids around fairly complex shapes with concavities can be generated easily. The...

Wave drag determination in the transonic full-potential flow code matrics

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...

TULIPS: A method to calculate transonic potentional flow about oscillating airfoils

A description is given of TULIPS - a method for Transonic Unsteady Lifting Inviscid Potential-flow Simulation. The Mathematical formulation and the numerical approach are presented for flow about oscillating airfoils. TULIPS is based on the numerical integration of the unsteady full-potential equation in generalized coordinates. The equation is...

Predesign for flow visualizer. Project: Flow Graphics, Work package: Visualizer for 3D flow-calculation results

The results of calculations of two- and three-dimensional 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...

Progress report of the development of a system for the numerical simulation of Euler flows, with results of preliminary 3D propellersllpstream/exhaust-jet calculations

Useful lifetime prediction software for plane semi-cracks in 3-D solid configurations

Computer programs are described to be used for fracture control purposes. Crack growth lifetimes can be predicted for plane cracks in 3-D structures. Values for stress intensity (K-) distributions at crack fronts are derived from data being available from literature for a restricted number of simple configurations. For arbitrary configurations...

Preliminary design and analysis of procedures for the numerical generation of 3D block-structured grids

An analysis of various alternative approaches in grid generation is presented. A grid-generation 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...

Axisymmetric liquid sloshing under low-g conditions: numerical simulations method (-reference manual-)

A mathematical model is presented for the description of axisymmetric three-dimensional transient flow of a viscous liquid in a partially filled cylindrical container under low gravity conditions. The mathematical model consists of the Navier-Stokes equations with either no-slip condition at the solid boundaries, and with the continuity of...

Data compression in computational fluid dynamics

Computations in numerical fluid dynamics create large sets of data. Transmission of these datasets requires a high speed communication link or, alternatively, the use of data compression techniques. This report describes the results of a study to the applicability of data compression techniques. An algorithm is designed that yields favourable...

Boundary-layer calculations on the leeward surface of a slender delta wing at incidence

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...

A survey of numerical methods for the calculation of inviscid, possibly rotational Euler flows around aeronautical configurations

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...