MICA Final Review Meeting
An abridged version of
Final overview of the Outcomes of the MICA Project
By Brian Spalding, (CHAM Ltd)
The aim of the MICA project, namely to create, test and validate a Model for Industrial CFD Applications, has been largely achieved. What has been demonstrated is that the use of Virtual-Reality-based user-interface software packages, by persons who may not be "CFD-literate", is practicable, and may often be the most convenient and economical means for solving their design and analysis problems.
Many lessons have been learned, one of the most important being the necessity to create and disseminate a flexible CAD-to-CFD translator program; these lessons will influence the manner in which the commercial exploitation will be carried out, by means of the Simuserve enterprise.
This review concentrates on spelling out the lessons and describing current plans for exploitation via Simuserve.
CHAM's experience of commercial CFD has, in the past, involved the provision of services of two kinds, namely:-
The idea underlying MICA was that many customers would benefit from a service lying between these two extremes. In such a service, CHAM, or some other possessor of powerful flow-simulation software, would perform the calculations, and possibly supply some advice, while the customer would be responsible only for setting up the problem and for reviewing and interpreting the results.
The customers tasks were to be made especially easy by the use of virtual-reality techniques, and by the attachment to the flow-simulation software of intelligent self-adaptive data-input modules. Moreover his financial commitment would be small, because he would not need to purchase either expensive software or still more expensive hardware; and he would need no highly trained CFD specialists on his staff.
What has become apparent, during the course of the MICA experience, is that:-
1.2 The spectrum concept
Two conclusions have been drawn from this experience, namely that, if the CFD-using community is indeed to be greatly enlarged by the use of the Internet:-
The spectrum would include:
In this spectrum-of-services concept, the expertise level of the customer would have to rise, the farther down the list appears the service for which he asks.
His choice would be made, of course, in accordance with his current capabilities, needs, financial circumstances and personnel resources; and the ability to choose differently at different times will, it is to be expected, be a benefit which he will value.
1.3The importance of the CAD-to-CFD connection
At the time at which the MICA project was conceived and planned, it was considered that the Virtual-Reality interface would be so powerful and attractive that it would meet all the needs of the prospective users.
The fact that these persons would already have spent much time in creating computer representations of their designs by means of CAD packages, and would not wish to start all over again in VR, was not recognised with sufficient clarity or give sufficient weight in the planning.
This fact was however quickly discovered as the interactions with partners began; and it was reacted to (albeit not so quickly) by CHAM.
Specifically, interfaces were created between certain CAD packages and VR, in the form of "file-translators". Two exist at the present time. The first translates STL files into VR-data files; the second does the same for DXF files.
It is true that more work is necessary in respect of the latter; for it has been experienced that the files which suffice for architectural-design purposes may not define building structures (for example) adequately for CFD. There may be gaps between walls and roofs; and inconsistent information may be provided about which is the inside and which the outside of the surfaces which bound a solid object.
The experience afforded by the MICA project has brought these matters to light; and solutions have been arrived at in all individual cases.
Ideally (from the CFD-software point of view), the CAD-package user who intends that his product should be used for CFD would learn how to avoid inconsistencies and omissions. Then the translator's task would be straightforward.
From the CAD-package user's viewpoint, however, it would be ideal if the translator were provided with sufficient intelligence to enable it to guess correctly what the user would have done if he had been "thinking CFD".
CHAM's current DXF-to-VR translator, for which "interpreter would be a better name, does possess some intelligence; and it will be equipped with more as experience is gained of what the most common deficiencies and inconsistencies actually are.
1.4 The reduced importance of "body-fitted" grids.
It was decided at the start of the MICA project that attention would be confined to flow-simulation problems which could be handled by cartesian or cylindrical polar grids. This was thought of as an unwelcome necessity, enforced by the limitations of time and resources.
As things have turned out, the limitation has proved to be advantageous; for it has led to such far-reaching enhancements to CHAM's pre-existing ASAP procedure (for fitting bodies with curved surfaces into regular grids) that, for many problems the solutions are of higher accuracy than body-fitted co-ordinates could provide.
The key elements have proved to be:-
1.5 The differences between the needs of the various application sectors
Ten application sectors were selected for attention in the MICA project. broadly classified into two groups, namely: "furnaces" and environment.
Even within these groups, so great a diversity of physical requirements was soon perceived to exist that the decision was taken to provide ten distinct special-purpose programs.
While considering the commercialisation of the products, it is now relevant to remark that differences exist in respect of the extent to which users in the different sectors are likely to benefit from MICA-type services.
For example, the customers for the flow-around-buildings product are entirely different in number, character and expectations from those concerned with explosions in oil platforms.; and the reliability of the predictions is also likely to be entirely different in the two sectors.
In the former, the customers are more numerous, the reliability of the predictions is greater, but the willingness to spend money on CFD predictions is lower. In the latter, the customers are far fewer, the reliability of the predictions is immensely lower, but the willingness of the customers to pay money is satisfactorily great.
In CHAM's view, both sectors of the industry can benefit from MICA-type remote-computing services; but they must be approached differently. The reasons are:
The more such distinctions are thought about and expressed, the clearer it becomes that each of the sectors requires special treatment. This does nothing to invalidate the MICA concept; indeed, the opposite is true. What it does do is show that the commercial-exploitation task is not easy.