PHLEX, an advanced hp-adaptive finite element kernel, incorporates the latest finite element technologies, including a flexible object-based database, a selection of linear and nonlinear solvers, error estimation, automatic mesh refinement, an advanced user interface and post processing. Through its open architecture, PHLEX allows Altair engineers (and ProPHLEX developers) to implement various physics simulation capabilities within the same adaptive finite element environment.

Based on the PHLEX kernel, we have developed a commercial toolkit ProPHLEX, which allows our customers to develop their own applications equipped with hp-adaptive mesh refinements and error estimation.

 

Reliability of Results Speed Ease of Use Open-Ended Design Lasting Economy PHLEX Demo ProPHLEX Developer Toolkit

Reliability of Results

Analytical results are not particularly useful if there is no reasonable and rational way to estimate their reliability. Even today the vast majority of engineering analyses are evaluated simply on the judgment and experience of the analyst, rather than according to some straightforward set of mathematically sound criteria. Often the analyst's judgments are sound. Too often they are not. PHLEX changes all that.

Solution Quality-Error Estimation

Solution quality is reported both globally and locally by means of highly robust residual error estimators and indicators pioneered by members of Altair's technical staff (see Residual Error Estimators on our Technology page). Error Indicators, carefully tuned for each application, provide PHLEX with information required to perform refinement and enrichment (see Adaptivity on our Technology page) of the computational mesh so as to satisfy the particular requirements for accuracy in any given analysis.

Control of Error- Adaptivity

PHLEX provides the ultimate in controlling the discretization error in the finite element method by supporting both manual and automatic manipulation of element size, location, and spectral order on fully anisotropic, unstructured meshes.  When mesh refinement is invoked, quadrilateral or hexahedral elements may optionally be divided into two sub-elements, rather than four or eight, in response to a directional component in the error indicators. This is commonly called anisotropic h-adaptivity.  Likewise, the spectral order of the elements may be enriched independently in the principal element directions, again in response to directionality in the solution error. This is commonly called anisotropic p-adaptivity.  The combination of the two strategies is called anisotropic hp-adaptivity.
In all cases, mass, momentum, and energy are conserved and the FE space consists of continuous functions. It is an elegant and mathematically robust system.

PHLEX is the only commercial computational kernel that provides such a powerful set of capabilities. Altair engineers pioneered these algorithms, and continue to lead the industry, both in research results and in successful application of the theory.

Speed

The time from concept to market must be minimized. That means that engineering analysis, once the reliability requirement is met, must consume the shortest possible wall-clock time.

Reliable Analytical Results

Revisit Reliability, above. If you act on bad information, you always lose time through rework.

Optimal Computational Strategies - Exponential Convergence

When the full adaptive power of PHLEX is applied, convergence of the solution occurs at the maximum possible rate, regardless of the problem class.
For problems which respond well to higher spectral orders, the rate of convergence is exponential. For problems which respond best to local mesh refinement, the rate of convergence is algebraic.

Vector/Parallel Implementation

PHLEX is uniquely structured, from the inside out, to make optimal use of vector and parallel computing systems. Elements are colored and grouped for vector/parallel assembly appropriate to the particular architecture of the host computer.

Task-Appropriate Solvers

The various engineering applications addressed by PHLEX naturally imply different sets of equations to be solved. The PHLEX suite of solvers continues to grow, but already contains a number of solution algorithms, each appropriate to its own particular class of equations. These include direct frontal and skyline methods, as well as conjugate gradient and GMRES iterative methods, with a number of preconditioning strategies such as diagonal, element-by-element, and Mandel.

Ease of Use

Reliable Analytical Results

Revisit reliability, above. It's always comforting to know the level of possible error in your computations.

Optimal Computational Strategies

Revisit Speed, above. Now you can decide how to balance time against certainty of computation, depending on the goal of each individual analysis.

Graphical User Interface

The look and feel of PHLEX is customized to each application through a MOTIF-based User Interface module which gives the practicing engineer convenient control of his analytical environment, and of his problem definition, execution, and presentation.

Software Compatibility

PHLEX interfaces nicely with industry standard CAE products such as MSC/PATRAN.

Visualization

The PHLEX library contains a complete engineering visualization package, based on 3D graphics package d3 available for use according to the application requirements. It can be configured to provide surface contouring, isosurfaces (with transparency), cutting planes, body surfaces, walkaround plots, velocity vectors, and many other modern visualization features with X, GL, and PostScript compatibility.

Machine Independence

PHLEX is a UNIX code, deliverable across the spectrum of UNIX processors, from workstations to supercomputers.  (An NT port of PHLEX will be completed during the first quarter of 1999.)

Open-Ended Design

Data Structure

The PHLEX data structure is based on an object-oriented paradigm, and contains Objects and Methods, as well as an Object-independent library for manipulating the Objects. It uses a data structure generator dsmake. It is open-ended from the start,  growing dynamically as new technology becomes available.

Programmer Utilities

Generic utilities such as Queues, Heaps, Stacks, internal and external Link-Lists, Block-extendable Arrays, a Message Handler, a Programming Statistics package, and convenient Assertions and Debug facilities make PHLEX applications easy to maintain and modify.

CASE Tools

PHLEX exists in an up-to-date software development environment designed to assure that each piece of this important tool is created and maintained under maximum quality and integrity standards.

Lasting Economy

Reliable Analytical Results

Revisit Reliability, above. If you use bad information, you always lose time and money through rework.

Optimal Computational Strategies

Revisit Speed, above. Time, after all, is money. Remember, however, that speed in analysis is not simply speed of calculation. The reliability requirement must be met, first and foremost. Otherwise, fast computation is worthless.

High Personal Productivity

Revisit Ease of Use, above. An analysis code should be a true friend, not a necessary evil. It should slide right into your environment and complement all your other tools.

Flexibility for the Future

Revisit Open-Ended Design, above. Hard-wired, closed systems can be produced more quickly (in some cases), and may often be tuned to process data very, very quickly. In the vast majority of cases, however, these apparent economies soon disappear.
The obvious need to expand and update any system as technologies advance is absolutely contrary to the notion of a tight, closed design.  The fundamental requirement for reliable output is the strongest case against tuning for speed of computation, at all costs.  In addition to everything described in the preceding pages, PHLEX carries with it Altair's corporate commitment to excellence. When our engineers customize PHLEX for your application, you get much more than the world's most advanced computational software. You get a long-standing tradition of technical and professional integrity.

Questions, comments or problems regarding this service? webmaster@tx.altair.com.

Copyright 1998-2002 Altair Engineering Inc.
7800 Shoal Creek Blvd, Suite 200N, Austin TX, 78757-1031 USA.