Where do we go from here? CFD in 2001

John C. Chien

(1). As the year of 2000 is coming to an end, very few people still remember the Y2k problem of the last century. The only thing you still remember is: we are still talking about CFD. Finally, we are going to move into the next century. (2). I am writing, because I am exercising my brain, and I need that whether I am working or not working. I guess, you are working because you have to support yourself or your family. (3). Before I say something about the year 2001, we need to get an overall view of the last decade, that is from 1990 through 2000. (4). First of all, after many years working with defense industries, I was finally able to put together an integrated CFD code for PC/286, including graphics on my own time, and on my own PC. It took me about 8 years to get the final idea in a working code. (from the time I bought the first Radio Shack model III sytem for about US$2500 in 1982 dollar.) It is interesting to know that it also took roughly about the same time for Microsoft to develop a good working Window 3.1 operating system. (5). So, in the last ten years, we have moved away from the super-computer systems and mini-computers into the network workstation/PC system. (6). At the same time, an interesting sytem of communication become available, that is "the Internet". (7). These two systems will start to change how we do CFD in the future. (8). In 80's, when the defense business was the main drive behind the CFD, it was necessary to work for a defense contractor to use the super-computer and to work on the CFD technology and applications. The nature of the work and the enviroment limited the access to only the best available engineers in the CFD field. So, there was no real competetion from other engineers, because they normally do not have the experience to access the mainframe or the technical problem. It provided a good shield for the CFD researchers. (9). With the support from the defense industries long disappeared, the commercial CFd codes become available for the general public, the commercial industries sector. The play field is now in the general public, and the access to the commercial codes is no longer limited to the shield CFD researchers in defense industries. This is the new play field of the post-cold-war CFD, commercial CFD codes and the commercial applications. (10). The other difference between 80's and 90's is the open-source-code vs the black-box approach. For a CFD researcher to understand the existing code, to modify the code with new ideas, and to apply it in solving the real problem, he must have the source code and the related document. This was the norm in 80's. With the commercial CFD codes in 90's, the users can no longer access the source code he is using. This coupled with the general trend of Object-Oriented Programming, and Component Objet Model for multi-tier network, the users in 90's commercial CFD codes become pure users, instead of the CFD researchers fo 80's. This is a fundamental change in the relationship between CFD and the researchers/engineers. (11). In 90's, there was also a very strong trend, which is still being continued, that is the company merger. The number of airframe companies has been reduced from 7 in US down to 3 or 2. The engine companies are also disappearing very quickly in the last 5 years. So, the CFD related departments also disappeared between each merger. As a result, the technical problem is ill-supported in the company, because the company tends to sell the codes as asset and keep the codes in transaction, without the supporting engineers naturally. (you can sell the codes, but you have to feed the engineers) There, the biggest mistake is the "separation of researchers from the codes". This is "irreversible process", and the end result is the company will have to die a second time. (12).The other big problem in commercialization of CFD codes is: it requires a lot of support engineers and sales persons, in order to keep the operation alive. As a result, the license fee is very high, relative to the 80's free source code approach. In addition to that, the research part of the code development is also limited, because of no profit no research. While the 80's approach was based on the company's contract work (or IR&D) with the government agency. There was minimum sales activities and essential no support at all. If you turn in the final source code to the sponsor, I guess, the sponsor can just read it and modify it to do whatever he likes to do. This is no so in the 90's black box approach. The user must depend on the support engineer to learn the tricks of operating the code, since the source code is not available to the user. (13). I am not about to tell you how to solve these problems, or how to approach these problems. But after reading the above message, I am sure that you have learned that the CFD of 90's is no longer the same as the CFD of 80's. It is hard to say that a CFD user of 90's commercial codes, is still part of CFD process at all. It becoming more and more like an engineering aid of 80's, although you might not agree with me in the observation. (14). And now with US$1000, you probably can get a PC with one GHZ CPU and 512Meg RAM system, which is 1000 times faster, 10,000 times more memory, two and a half times cheaper than my 1982 Radio Shack Model III system. And I suddenly realized that, I can become the CFD researcher, the developer, the boss, and the global market is just at the touch of the Internet connection. (15). The availability of the computing enviroment and the accessibility of the global market through Internet, will finally put the control of the technology development at the finger tip of an old fashion CFD researcher. (16). As you move into the next century, you will probably still worrying about the convergence issue of a commercial code. But at the same time, a brand new generation of CFD will emerge silently, across the Internet. I am not sure, whether it is still an integrated CFD code in single program, or distributed components across the Internet. I am sure that, it is not going to be the current approach. That is the rather in-efficient, backward approach of 90's. (17). By the way, you are encouraged to think about all these issues, because it is you who will be in control of the future CFD.