3D finite-element software runs fast on standard PCs

Paul Boughton
A prevailing view of three-dimensional finite-element software is that run times may extend from hours to days. However, Field Precision has developed novel software to generate accurate results for real-world design problems in minutes. This high-speed operation is the result of a combination of new approaches and common sense:
First, the Metamesh program has the capability to generate structured, conformal meshes (which is a feature that is claimed to be unique). Such meshes combine the accuracy of conformal elements with the efficiency of strict logical order where element relationships are determined by index operations.
Next, the solution programs are written entirely in modern Fortran, a language that Field Precision describes as 'unmatched for serious number crunching.'
In addition, the design of the programs avoids stratagems like object-oriented programming that make coding easier but add computational overhead. Instead of using generalised libraries, mathematical routines are hand-coded for higher efficiency, and the programs are carefully analysed to remove redundancies and minimise disk access.
The solution techniques are chosen to involve the fewest operations and to make minimum demands on memory (for example, the scalar reduced-potential method for 3D magnetic field calculations).
According to Field Precision, the end result of this effort is to make three-dimensional simulations practical, even on ordinary personal computers. The performance can be illustrated with an electrostatic calculation, the injector for the DARHT Accelerator at Los Alamos National Laboratory. The challenge is to model the full volume of a 6.3m high vacuum chamber while achieving sufficient accuracy to calculate transport of a space-charge-limited relativistic electron beam across an acceleration gap. For a realistic test, the calculation was not performed on an expensive, optimised workstation. Instead, the engineers used an off-the-shelf $600 HP computer (Windows Vista 64, Intel Core2 Duo E8400 at 3.00GHz). The mesh (with 1.75million elements) took 18 seconds to create with Metamesh. The finite-element solution with the Hiphi program involved the generation and matrix inversion of a set of almost 2million node equations. The total run time was under five minutes (287 seconds). With such short run times, users have the latitude to do what-if experiments and to investigate a wider range of parameters and approaches.
Field Precision has stock high-speed application packages for high-voltage engineering, electromagnet design, electron and ion guns, RF and microwave technology, X-ray sources and permanent-magnet devices.
For more information, visit www.fieldp.com

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