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High Performance Computing and Networking essential in the Automotive Industry
High Performance Computing and Networking has become an essential element in the design, development and production in the automotive industry. For example, cars designed and built in the last ten years own their aerodynamic shape, structural integrity, noise level in the passen ger compartment, engine emission levels, and fuel consumption efficiency, in large part to simulations done on supercomputers or parallel High Performance Computers. The high speed networks anable design teams to collaborate while working at different company plants and often in different countries.
The HPCN Europe 1997 event is scheduled from April 28 30 in Vienna, Austria. The event focusses on advanced solutions for industry, research and education based on such machines as workstations, servers, high-performance systems, and networks. HPCN Europe '97 aims in particular to show the importance of HPCN technology for the industrial end-users. The event will comprise an Exhibition, as well as a Conference. An end-user track will focus on HPCN end-user applications in industry and academia. It shows the ability of HPCN technologies to create a competitive edge in industry.
As users of cars we only see the final product, when on sale. Our first reaction is often perso nal and depends on whether we like its shape. Once drawn to it we check whether it handles well during a test drive, feels safe, quiet, economic to run and so on. Our responses to these questions eventually decide the popularity of the car model and the success or failure of the company which produced it. Before a new car reaches the sales showrooms it is often in the design and development phase for at least five years.
Wind tunnels
Car makers study aerodynamics because it affects two primary aspects of car performance; fuel consumption, directly affected by air flow drag, and handling, directly affected by cross-winds and indirectly by aerodynamic lift. Designers traditionally used wind tunnels to evaluate the aerodynamic efficiency of car designs. This is however, an expensive process since each test requires a prototype to be built. While some wind tunnel tests are still done in the final stages, computer simulations are now used for ironing most problems. Flow fields associated with various body shapes are predicted computationally so that designers and engineers can evaluate the impacts of any changes and save time and money that would otherwise go in to tri al-and-error testing of prototypes. Ultimately, computational analysis provides a flexible tool to speed up the design process.
A car or truck is powered by a carefully timed sequence of explosions in its engine's combusti on chambers. Unfortunately, this process produces more than horse power. It also generates several types of air pollutants. Increasing public concern over these pollutants, as well as increased government regulation has prompted manufacturers to step up their emission control research. Along with devising various types of converters and valves to trap and control pollutants, the industry is being studying combustion chemistry and physics in an attempt to combat pollution at its source.
When fuel burns in a car engine most of it is transformed chemically into carbon dioxide and water. However, some of it can end up as bits of carbon, or soot. This soot particles tend to stick together and grow in size. By studying their origin and behaviour one can design an engine and modify its operating conditions to minimise soot production. Having cleaner emissions also reduces costs for pollution control devices once the car is built.
The chemistry of fuel-air ignition is another factor engine designers tackle early in the design process. Ignition is a complex sequence of chemical events immediately preceding combustion. Engineers need to solve the problems of how to ignite the fuel-air mixture using the least amount of energy, and how to ignite it to best facilitate combustion. Ideally, engines should run lean, (minimum fuel) using lots of oxygen to completely burn the fuel. Running lean provides thermal efficiency and pollution advantages, but these lean mixtures are difficult to ignite.
Engine flows
The study of ignition chemistry involves simulations of various flame shapes to determine changes in the temperature and concentration of several chemical species in a combustion chamber as a function of time. The calculation typically involves 24 chemical species and 150 chemical reactions and account for physical phenomena such as molecular diffusion, convecti on and conduction. Engine flows and combustion are other areas which benefit from computa tional analysis. Engine flows are extremely complex. Typically they are three-dimensional, compressible, transient, turbulent, multiphase (when sprays are used, as in direct injection engines) and reactive during combustion. The equations used to model the flows are the conservation (transport) equations applied to mass, momentum in each direction (Navier Stokes equations) and energy. In addition, they account for each chemical species (perhaps ten) and for turbulence, droplet spray motion and combustion. To solve these problems one requires very fast systems with large memories and data stores.
The advent of integrated 3-D graphics and video are helping enormously in the visualisation of the simulation results. Designers and engineers can now see the hot spots and weak flows of their designs and try different geometries and vary fuel injection rates to iron out these pro blems prior to building prototypes. For example, Ricardo, a UK company which provides car engines for Ferrari, are using these computational techniques on a Cray machine and claim to have reduced the time to market of their new engine from six years to three. They also claimed to have achieved 10% emission reductions, 20% fuel efficiency, and enhanced durability by hundred thousand miles.
Low frequency compartment noise caused by vibration of the surrounding body panels is a potential vehicle problem. Bumpy roads, aerodynamic inputs and a vehicle's power compo nents can initiate low-frequency vibrations in panels. The vibration panels then act as drum heads or loudspeaker diaphragms, producing sound waves, and creating an annoyance to the vehicle's occupants. Structural acoustic analysis codes are now used to provide designers and engineers with a means to identify and correct potential noise problems early in the develop ment phase.
Structural codes such as MSC/Nastran and PamCrash are also used to understand and minimi se the dangers to passengers when cars are involved in crash accidents. In conclusion, the car industry is using HPCN as a tool to deliver product quality, accelerating development cycles and in conserving resources that in the past went into building and testing development mo dels. With the ever increasing number of cars on our roads there are still many challenges, including the new anti-pollutant EC emission controls, e.g. EC2000 and EC2005, which need to be addressed. Manufacturers will in the future have to rely more and more on HPCN to remain competitive.

Chemistry has entered a new era with High Performance Computing and Networking
Chemistry is at the heart of most materials and products common today. Societies rely on a diversity of materials, steel for cars, fibres for clothes, building materials for houses, paints, fertilisers, pest control chemicals, pharmaceuticals and other health care products, fuels and semiconductors for electronic devices. Many material in common use today are synthetic. They were designed by chemists, at first by testing related compounds using empirical tri al-and-error methods, but more recently using computers and the quantummechanical appro ach.
Materials are described and classified according to magnetic properties, their hardness, melting point, optical appearance, electrical conductivity, and chemical reactivity. In theory, if we could construct mathematical equations which describe these properties, we could predict how any material behaves by simply solving these equations. But to find the equations we need first to understand the physical laws that govern the properties of material.
We now know that electrons play a crucial role in the properties of materials. Electron create and break chemical bonds, and their distribution determines many chemically important materi al properties such as the shapes of molecules, the arrangement of atoms in solids, the forces between atoms, and their electrical properties, (whether they are insulators, semiconductors, or metals). Even the complex macro-biomolecules in living organisms are ultimately governed by the electrons of atoms forming these molecules.
Quantum mechanics
It is now over seventy years since scientists formulated the theory of quantum mechanics which allows a quantitative prediction of the distribution and energies of electrons. The fundamental equation of quantum mechanics, is the Schroedinger equation, (named after the Austrian physicist who proposed it), and contains the key to understanding the properties of matter. It gives a complete (statistical) description of the electrons in atoms, molecules and solids. Solving Schroedinger's equation for a given arrangement of atoms reveals the distribution of the electrons and the corresponding energy of the molecule or solid. From this, one can determine things such as the way atoms are arranged in a molecule or solid when they are in their lowest total energy state, (so called ground state), and how to calculate the forces binding the atoms together. The ground state is generally the most stable form of the molecule and thus, the form the molecule commonly assumes in nature.
To determine the ground state of a molecule or solid, researchers choose an arbitrary atomic configuration and calculate the total energy. They then, change the geometry, recalculate the total energy and compare it with the previous value. If the new value is lower, this procedure is repeated until the structure of lowest total energy is found. This structure is taken as the actual structure of the molecule or solid.
One can then proceed to pull the molecule or solid apart, step by step, recalculating the total energy for each step until it falls apart. This series of calculations reveals how strongly the molecule or solid holds together and how much energy is needed to break it. Another approach is to start with isolated atoms or molecules and bring them together through a series of calcula tions to form a new molecule, thereby revealing the new molecule's stability. These two procedures - breaking and making chemical bonds and forming new compounds - are at the heart of chemistry.
All this sounds very easy, but in practice, there are several difficulties to overcome. Even small molecules have many electrons and each electron interacts with all the others as well as the atomic nuclei in a molecule. For example, water, a relatively small molecule contains 10 electrons and three atomic nuclei. The metal tungsten, (used as a filament in light bulbs), each of its individual atoms carries 74 electrons, and to form even a small piece of metal requires about 1023, (ten to the power of twenty-three), of these tungsten atoms.
Supercomputers
A second difficulty is that the motion of electrons is not governed by classical mechanics, which have been used very successfully in engineering disciplines, but by the laws of quantum (statistical) mechanics and in some cases it also includes the theory of relativity. For many years scientists struggled with these challenges and although they formulated many brilliant methods they were reduced to calculating the already known properties of small molecules. With the advent of supercomputers and parallel High Performance Computers, chemistry has entered an era where simulation of real-world chemical systems became a reality. Chemists can now tackle complex systems that are difficult or even impossible to study experimentally. Molecules, solids, and surfaces can be constructed and visualised graphically. By performing complex calculations and looking at intermediate steps not accessible experimentally, scientists can now study in detail and thus control chemical processes. In this way, the computer-aided design of new materials has become a reality and is revolutionising the way chemists develop new materials to satisfy human needs.
In 1985, Du Pont de Nemours, the largest chemical company in the USA, started to use supercomputers for molecule manipulation and design of new materials. Now all major chemi cal manufactures are using these techniques. Applications packages such as AMBER, (Assisted Model Building with Energy refinement), the Ab Initio packages GAUSSIAN and GAMES, the UNICHEM package and so on, are providing a wealth of procedures to explore and understand the properties of new materials.
AIDS
Another important area of application is in medicine where action drugs are designed and used to block a specific site of a macromolecule, termed the drug receptor. As the structures of more of the body's macromolecules become known , the design of antiviral drugs for specific functions, such as for example, blocking the HIV virus which causes AIDS, can be tackled.
One can name thousands of uses which High Performance Computing is indispensable. The HPCN conference and exhibition, scheduled from April 28 to 30 in Vienna, Austria, is helping to promote this important industry and broaden the awareness of its great beneficial potential to society.

Commercial added value centre stage at HPCN Europe 1997
"More than ever before commercial added value is at the heart of industrial High Performance Computing at HPCN Europe", says Royal Dutch Jaarbeurs' exhibition-manager Mr Peter Linnenbank. The fourth edition of this international event is scheduled for 28 through 30 April 1997 in the Austrian capital Vienna and it is unprecedented that, endorsed by the European Commission, scientific conference and a trade exhibition in the field of High Perfor mance Computing and Networking are integrated.
The scientific conference programme offers a number of different sessions and is sponsored by Foundation HPCN Europe, chaired by prof. dr. L.O. Hertzberger of Amsterdam University. One of the sessions is targeting industrial applications, while prominent industrial businesses by the likes of DASA, Daimler-Benz and Shell will be amplifying their high-performance compu ting applications for research and development, which were developed in their own laborato ries or in close collaboration with the scientific world.
Royal Dutch Jaarbeurs will be organising the exhibition, designed to be a platform for suppliers eager to show their hardware and applications to end-users in e.g. the automotive and aerospa ce industry, the financial world, service providers of emerging media and engineering within industry. New applications, emerging in the HPC marketplace, are database management (datamining & datawarehousing), World Wide Web-applications and system integration.
As a supplement to the businesses boasting a long history in servicing the high-end market, an increasing number of hardware and software companies have emerged concentrating on the low-end HPCN-market. In the wake of evolving technological developments personal compu ters and workstations are more high-powered than ever before. They provide qualitative and 'unexpensive' alternatives and solutions. These devellopments will be clearly visible at HPCN Europe 1997.
Tutorial on MCAD and High Speed Networking Environment
The HIPPI Networking Forum (HNF) will present a three hour tutorial on MCAD and the High Speed Networking Environment at HPCN. This tutorial will cover subjects such as Building your high speed network', Gigabit to Gigabit Infrastructure', Cost Justifications for the High Speed Network' and Storing, Moving and Sharing Data'. Future trends in HIPPI and Gigabite Networking will also be covered as weel as case studies from high speed networking users.
The HIPPI Networking Forum is an international group of professionals dedicated to advan cing the High Performance Parallel Interface networking standard and accelerating the growth of HIPPI connectivity for a broad range of applications.
The devellopment and release of network interface cards providing fiber-optic-based Serial High Performance Parallel Interface connectivity for various bus architectures completes the suite of products necessary to build complete SuperLANs'. However, at present, HIPPI is the only such tehnology. Fibre Channel provides gigabit-per-second rates, but most offerings focus on peripheral connectivity.
VICE PRESIDENT CYBERNETICS AND SIMULATION FROM DAIMLER BENZ: HPCN Europe is a very attractive event for industry'
In automotive industry design to cost and design to market are key issues of the future, according to Vice President Cybernetics and Simulation Gnther Hfner from Daimler Benz. "This requires the introduction of new techniques and a redesign of the development process. The use of HPC in the field of CSM and CFD reduces the computing time dramatically and allows an extended use of simulation within the various stages of a design and hence increases the level of confidence into a new on. Together with the introduction of new networking techniques HPC will help to ensure the competivness of our products".
Together with partners from universities and other campanies Daimler Benz Research is involved in various HPCN related fields like CFD, visualisation, coperative work and distribu ted computing.
Hfner: "HPCN Europe 97 with its vendor exhibition and technology demonstrators will show HPC at work. This allows a realistic estimate of the state of the art and the limitations of the technology in the near future, which makes this event very attractive and will contribute to a fast dissemination of HPCN techniques in industry. It turns out that with increasing computing performance HPC related fields like pre- and postprocessing are becoming more and more the bottleneck and mist be adressed within HPCN Europe 97. The academic sessions of HPCN Europe can give a better understanding of future trends and their consequences for our work and decisions".
The Austria Center Vienna a world-class conference complex
Vienna's traditions as a host city go back many years. Ever since 1814-15, when the Congress of Vienna waltzed to the concert of Europe under Metternich's guidance, the Austrian capital has had a worldwide reputation as a conference city. It again became a focus of international attention when the UN made Vienna its third headquarters, together with New York and Geneva over 25 years ago.
Since the construction of a world-class conference complex, the Austria Center Vienna, Vienna has been here to stay as a meeting place for the world. Today the Asutria Center Vienna (ACV) is crucial to Vienna's role as one of the key conference destinations. In the ACV there are 14 halls, large and small, providing a combined capacity of 10,000 delegates. And there are 170 conference rooms of varying sizes, offices and exhibition space. The ACV has excellent connections with all important areas of the city.
Most powerful machines create advanced solutions for industry
Twice a year a list of the worlds fastest 500 computers is compiled by a team of scientists from the University of Mannheim and the Oak Ridge National Lab in Kentucky. This TOP 500 is twice a year presented, in Autumn in the USA at the Supercomputing Conference held (last time in November 1996 in Pittsburgh PA) and in Spring in Europe at the HPCN Europe Event. HPCN stands for High Performance Computing & Networking, HPCN Europe 1997 is sche duled from April 28 30 in Vienna, Austria. The Event to focusses on advanced solutions for industry, research and education based on such machines as workstations, servers, high-performance systems, and networks.
HPCN Europe '97 aims in particular to show the importance of HPCN technology for the industrial end-users. The event will comprise an Exhibition, as well as a Conference. An end-user track will focus on HPCN end-user applications in industry and academia. It shows the ability of HPCN technologies to create a competitive edge in such industries as: banking & insurance, entertainment and other service providing and networking companies, in automotive and aerospace, manufacturing, consumer electronics, medical, chemical & pharmaceutical companies etcetera.The machines that make it to the TOP500 are specially designed to do such work. What figure does Europe cut on the TOP500?
The most powerful machine in Europe today is in the UK a Fujitsu's VPP 700 with 46 proces sors at the weather forecast center ECMWF in Reading. This number 10 on the worldwide list moved from Cray machines to a Japanese vendor. European machines are rare in Europe (and elsewhere), and only a few of the European installations are European: Parsytec PowerPlus machines in Germany (Heidelberg Paderborn, Hamburg and Chemnitz) and one in Sweden; Meiko has two installations in Europe. Parsytec has an installation in Japan and Meiko two in the USA. Of the European supercomputers 83 % are American and 11% Japanese. This underlines again the dominance of US vendors but the Japanese are improving on market share; NEC and Fujitsu/SNI have nearly doubled their percentage compared to a year ago. Number one in Europe in machines on the vendors side is Cray, with 42 systems and 783 Gflop/s. Combined with the Silicon Graphics figures (20 machines and 126 Gflop/s), SGI/CRI has nearly 50% of the machines and 52% of the totalled European Rmax. They are followed by IBM, 35 computers of Europe and 322 Gflop/s.
Germany is as strong as ever and again the leader in Europe with 39% of the computers in Europe, and 10% worldwide. This TOP500 shows that the UK houses 18 systems and there are 17 machines in France.
Switzerland is traditionally well represented in the TOP500, even when the machines that are nor "purely Swiss" (i.e. installed at CERN or internally at a Silicon Graphics plant) are not taken into account. In total 9 machines with an Rmax of 151 Gflop/s are installed between the Alps. It can be shown that although a small country, it has the highest usage of high-performance computing when combining economical factors like number of inhabitants or gross national product into this study.
Looking at the top 25 installations we see that they hold positions in the world-wide list ranging from 10 to 100. So, first, Europe is literally marginally present in the "Top Ten" and, second, in the list of the 100 fastest machines there are 1/4 European entries. The latter is consistent with the overall picture: the total number of systems in Europe is now 132 which is 26% of the 500 worldwide installations.
Italy's highest entry is a T3D at 159. Eastern Europe falls back, only Convex machines in Poland (408) and Slovenia (325) are listed. Austria shows at 359 a PowerChallenge at the Technische Universitt Wien. Spain shows a 44-processor SP2 at 210. The last place in the list ( 500) is for Luxembourg with an SGI machine at the Goodyear Technical Center. Belgium, Greece and Ireland have no TOP500 machines.
Technology Demonstrators Display
The Technology Demonstrators Display will demonstrate real-world applications that are running live on HPCN Europe 1997. Typical demonstrators show that HPCN is not just a research topic, but a leading technology with important applications.
The demonstrations will include: Real working applications, i.e. leading-edge applications of a the real-life nature, new emerging applications, technology transfer, path-finding collaborations with end-users in industry (segments).
At the moment the TDD board is "chewing" on the proposals. Some of the submitted topics include:
Performance Measuring and Monitoring of a protocol and implementation that provides access to distributed, decentralized, multi-format document collections over WWW. A suite of software systems, communications protocols, and methodologies that constructs a virtual work environment on multiple computer systems connected over the Internet, to form a "Collaboratory". A High-Performance Fortran project. Molecular Dynamics applied to paint manufacture. Datawarehousing aplication. An interactive Satellite Image server.

Benefits to Business and Industry
The international HPCN Europe conference and exhibition is to be held in Vienna, on 28th -30th April this year. This annual event is designed to raise awareness on the likely benefits of High Performance Computing and Networking, by bringing end-users, experts from enabling organizations and technology suppliers together. In this way the HPCN skills and technologies can be available to address identified user needs.
Business is beginning to see HPCN not as a cost but rather as a necessary investment. It provides functionality not available or economically viable when using conventional computing and it is required for scalable applications which make large demands on computing power and/or Networking. Examples include Information Management Systems, simulations in engineering, designs of cars and aircraft, and also the financial and retailing businesses. Somer field, the food retailing company in the UK, recently floated on the London stock market, is given here as an illustration of how HPCN can help a company to become profitable.
Somerfield has reported (on 21st January), first half pre-tax profits of 54.6 million a rise of more than 26% on last time. This met market forecasts of 54 million to 56 million UK pounds. Total sales reached 1.7 Billion pounds, a 1.3% growth. Chief executive David Simmons said: "the strength of our financial performance and our greatly increased investment capacity provides Somerfield with a solid base for future expansion".
In a recent talk, Chris Mason, the Somerfield computer manager, explained how HPCN turned out to be a White Knight helping to transform the ailing Gateway company, on the brink of going into liquidation, into a newly thriving profitable retail company, named Somerfield. He claimed that "Gateway was kissed by a frog and although not transformed into a Princess it became a Knight". He went on to say that food retailing may look deceptively simple, but in reality many strange life and death happenings take place in the operational arena.
Mason mused at the folly of banks, who profess to want to expand their financial services, and yet push most of their customers out in the cold, forcing them to use automatic cash machines. In contrast food retailers, such as for example, Sainsbury, Somerfield, and Tesco in the UK, have extended their opening hours and in addition provide loyalty cards, to gather information and provide targeted sweeteners when necessary to their customers, to ensure they do not defect to the competition.
Marketing in the nineties has become more discerning and instead of relying just on mass advertising, it now employs individual customization and agile marketing. With this approach there has been an explosion in data collection, and data mining has become a key operational instrument for achieving and maintaining profitability.
To illustrate the enormous size of this explosion in data collection, let us use a typical scenario from a supermarket chain. Consider a customer spending 25 pounds for food each week at a supermarket, buying say on average, 25 items out of a range of 1000 different items held on shelves, and the retailing company has 7 million customers across the country. A year's data amounts to 100GBytes, (one hundred thousand million bytes), or more. The task is to turn this data into knowledge and then convert it into company profit. Somerfield has done this by separating operational systems, based on IBM mainframes and Information Management Systems (MIS). For (MIS) they opted for a moderately parallel platform using a Pyramid RM1000 with 8 Nodes and use parallel ORACLE as their main software.
Chris Mason, concluded that "HPCN equals business benefit", and in their case turned an ailing retail company into a profitable one. Somerfield's successful floatation on the London stock market became possible because the new HPCN based IT infrastructure, assured investors of the company's profit growth potential. The company pre-tax profit results just announced, justify this claim.
In brief, take-up of HPCN technologies and services can benefit many businesses and sectors of industry, including small and medium size enterprises. In areas such as simulation, embedded systems or information management and decision support, both computing and networking are matters of great importance. The HPCN conference and exhibition in Vienna provides a great opportunity to find what is presently on offer in this exciting field.

The Aerospace Industry essential in the Automotive Industry
The aerospace industry has benefited enormously from using computers and is one of the industries which provides the financial impetus for the development of parallel and High Performance Computers. Aircraft design relies greatly on understanding the behaviour of air flows at high speeds. The difficulty arises because the mathematical equations which govern air flow are very complex, especially at near, or, above the speed of sound when the flow becomes non-linear. In the past and to a lesser extend now, engineers had to make judicious simplificati ons to solve these equations to achieve important insights.
In most high technology industries the margin between success and failure is very narrow. In the past three decades very few commercial aircraft were successful to make their manufactu rer profit. The Boeing aircraft and the European airbus are notable exemptions. The economics of aircraft operation are such that even a small improvement in efficiency can translate into substantial savings in operating costs. Therefore, the operating efficiency of an aeroplane is a major attraction to potential buyers. This provides aircraft manufacturers with a compelling incentive to design the most efficient operating aircraft.
There are three main areas for improving operating efficiency. Namely, the use of light compo site materials, improved aerodynamics, and better engine efficiency to save fuel. Aerodynamic efficiency is measured by the lift-to-drag ratio and remains more or less constant until the speed of the oncoming air gets near the speed of sound. As it reaches supersonic speed there is a rapid drag rise, and the lift-to-drag ratio suddenly decreases with a correspon ding decrease in aerodynamic efficiency.
Supersonic flow
Although the major part of a commercial aircraft flow-field is subsonic, the air flow behaviour is such that it contains pockets of supersonic flow on parts of the frame and especially on the wings. It is this localised supersonic flow which causes the loss of aerodynamic efficiency to occur. The transition from supersonic to subsonic flow almost always occurs through a shock wave, a condition that gives sudden deceleration and increase in pressure. The appearance of a shock wave can be compared with the breaking of a wave on the shore. When the wave height becomes comparable with the water depth, different parts of the wave will move with different speeds. The wave crests now move faster than the troughs and as a result, the wave steepens. At some point the wave crest overtakes the trough and the wave breaks.
A similar phenomenon occurs when a stream of air moves at supersonic speed past a fixed disturbance. The underlying physics are complex but in simplified words, the pressure wave created by the disturbance will travel downstream, interact with air which is slightly viscous and develop in a similar fashion as the wave on the shore. Dissipative effects inside a shock wave produce a resistive force, known as wave drag, which causes the rapid loss of efficiency.
Transonic flow is characterised by the presence of both subsonic and supersonic regions of flow and the formation of shock waves. This is a non-linear situation and unfortunately, although linear problems are well understood, mathematicians can only muster a few ad hoc methods for solving non-linear problems. In principle, it is possible to solve numerically, using computers, the full Navier-Stokes equations of fluid flow including the viscous effects. In practice, there are considerable difficulties in representing the viscous terms accurately and in modelling turbulence.Thus the development of computational fluid dynamics (CFD) has paid tremendous dividends to researchers analysing complex flow phenomena. The most important factor for these achievements has been the development of supercomputers and in the last few years parallel High Performance Computers. The HPCN technology has made it possible for the computation of the three dimensional viscous external flow-field on an entire aircraft frame. These simulations are done for different designs to obtain the most efficient shape under operating conditions.
Flow situations
Another challenge for engineers is solving the problems in the extremely complex flow situati ons encountered in advanced aerospace engines. The flow in modern propulsion systems is also transonic, but in addition to the time-dependent features, the flow may include particulates through dust injection and/or surface erosion, two phase flow, chemical reactions associated with combustion, very high temperatures with non-linear heat transfer and jet mixing.
Turbomachinery, combustions, and jet mixing are three particular areas in advanced aerospace propulsion systems in which CFD is a key element in advancing the state of the art. Accurate experimental data have been extremely difficult or impossible to obtain in these areas, either because of non-linear flow, or, because it has not been possible to experimentally simulate the actual flight environment. In turbines non-linear flow products varying pressure and shear stresses whose contribution to aerodynamic losses is important when assessing engine performance.
Also, turbine temperatures are extremely high and are in fact, the primary limiting factor in turbojet engine design because of material limitations. Furthermore, modern compressor rotors operate in the transonic flow regime, in which the flow entering the rotor is supersonic while its axial velocity component is subsonic. As a result of this transonic flow, an intricate system of shock and expansion waves exist in the blade passage.
Computer simulations
For most of these phenomena, little or no time-accurate experimental data are available for analysis. Consequently the numerical solution of the time-dependent compressible Na vier-Stokes equations using fast computers with graphics for visual observations is the only cheap flexible way to tackle these problems. Another area which is heavily dependent on computer simulations is electromagnetic. This is of paramount importance in shielding the aircraft's electronic systems and preserving its physical integrity.
Many computer application packages are available, such as FLOW-3D, LS-DYNA3D, CATI A, TRANAIR, etc., and this made it possible to reduce the time and cost of aircraft design significantly. It also made it possible to prove the viability of a new aircraft with very little recourse to very expensive wind tunnel experiments. Aircraft manufacturers will in the future rely even more on HPCN to remain competitive.
The HPCN conference and exhibition, scheduled from April 28 to 30 in Vienna, Austria, is helping to promote this important industry and broaden the awareness of its great beneficial potential to society.