CFD Online Discussion Forums

CFD Online Discussion Forums (
-   Main CFD Forum (
-   -   part-time-cfd (

Michael January 29, 2000 08:00

Hy friends,

I want to ask something that goes a little bit aside the technical area of cfd and I'm in special interested in answers of younger cfd-people. After university I'm working now 1,5 years with cfd. We are a smaller company and started a at that time with cfd with me and one othe nevcomer as beginners. Now we see the difficulty in future, that it is not possible on the one hand become an cfd-expert with all the things around this (hardware, software, a bit CAD) and on the other hand to become an expert of "convential design" in the area the company works. Do other new-cfd-people have the same problem ? Is it different in companies with a big groups of people working in cfd ? What do more experienced cfd-people say to that problem ? Are you expert only in cfd or are you expert in cfd AND say water-turbines ? Thanks

John C. Chien January 29, 2000 22:33

Re: part-time-cfd
(1). I think your question is a very good one, and also a very tough one to answer. (2). First of all, you need to put aside the business part, then I'll try to address the question in the reverse order. (3). I think, one can be an expert in water turbine alone.(period) That means, you know a lot about the water turbine.(period) This can be accomplished in any way you want.......(you can fill in the blanks) (4). "Are you expert in CFD?" is the point of confusion. CFD is just "Computer + Fluid Dynamics",and both the computer and the fluid dynamics are general terms. That means, it will take a long time to know a lot about the computer part of CFD and the fluid dynamics part of CFD in order to become an expert. The question is: under this definition, do you still want to be a CFD expert? do you think it is necessary to become a CFD expert? (5). So, I guess, it is perfectly all right to be a non-expert in CFD. I think, you are still not convinced. (6). I'll take a look at the problem from a different angle. Let's say you are an expert in water turbine, and you know a lot about it. Then the question is: can you improve the performance of the water turbine by performing CFD analysis? Since I don't have the answer to this question, I will have to assume that the answer is "yes". Then naturally, you can say that you are now an expert in water turbine, and you also knows how to improve the performance by using CFD analysis.(period) (7). So, now you know that "are you expert only in CFD?" is a rather vague question, and even if I say I am an expert in CFD, you still don't have any slightest idea whether I can perform a water turbine CFD analysis to improve the performance or not. (8). Now, you probably think that you are from the wrong side of the engineering. (But, if you read this question first, then you will get a better idea. That is : are you an expert in computer programming?) (9). The hard reality is: CFD analysis must be part of the design processes (loops), otherwise, it will become only a research topic and paper publishing. That is, you are a professor or a researcher doing research project and writing reports. Now you see a different type of CFD activities exists. And even in this research environment, you can only pick a subject a time. (10). In a large company, say an aerospace company, when they are designing a new aircraft, they have to do a lot of analysis, including CFD analysis.(on different possible configurations) Then they will need more engineers to do the analysis in order to meet the "schedule". But if they have long term contracts, they can have a core group of people to do the CFD related research and tools development for other engineering groups. (11). And sometimes, these core group engineers will form their own company to provide the similar service, whether it is code development or the problem solving. (12). So, that establishes more or less the CFD related activities and industries. And the CFD consulting business will grow and shrink based on the business and the market laws. The same applies to the academic research part. It will expand and shrink based on the available contracts and budget. (13). In other word, if you are interested in the academic CFD research activities, then you don't have to know a lot about the water turbine in order to publish a CFD paper. (14). On the other hand, if you are involved in water turbine design, all you need to know is the specific CFD analysis which can improve the water turbine performance. (15). So, what is the key issue in the whole discussion? If you are in business with a lot of competition, say in water turbine field,then in order to survive, it maybe critical for you to know how to improve the water turbine performance through the use of CFD analysis. Otherwise, if the customer is only interested in the cost, a simple analysis is good enough. (16). There are other occasions when there are enough money around and there are no other working methods available, then CFD analysis will be the only solution, such as the design of new aerospace vehicles, etc. Naturally, in this case there will be people working on the design, geometry, meshes, solvers, graphics,... in order to make the whole design loop practical. (well, Wright brothers invented the airplane, and Dr. Roache published his CFD book, How did they do that?.......Back to the basic principle: you have to know what you are doing.(period) )

clifford bradford January 31, 2000 14:13

Re: part-time-cfd
as john said your question is thorny. i think you can be an 'expert' in both CFD and an application of fluid mechanics or in just one. but what does it mean to be an 'expert' in CFD? many CFDers write code and many hardly ever do so and some do a little. you don't have to be an expert code write to be an expert CFDer. CFD has become such a broad area that a person may have great knowledge of CFD applied to high Reynolds/Mach number aerodynamics but might know little about schemes for incompressible flow he would still be a CFD expert. i suppose those who have wide expertise over most of the field would be a guru? on the other hand there are people who know a lot of CFD which require you to know fluid dynamics well but aren't highly specialised in one area of fluid dynamic applicaions like water turbines. these people are generic 'CFDers'. on the other hand if you are water turbine expert who knows a lot about CFD you are not likely to be called (or call yourself) a CFDer. i would say though that most people who spend a lot of time doing CFD analysis are specialists in a given area of fluid dynamic application (unless they are mathematicians). even many of the people who come up with new schemes and publish in 'Journal of Computational Physics' are typically people who would consider themselves 'aerodynamicists','turbomachinery specialists' or 'hydraulic engineers' etc. it is the nature of engineering that we don't emphasize our technique (CFD) as much as we do our function (water turbines etc) so i'd call myself a gas turbine guy who knows something about CFD while john is a (i think) turbine guy who knows a lot about CFD (i'm sucking up to john here) and you might be a water tubine guy who knows something about CFD. in any case our main reason for doing CFD is to do better at our main job be it airplanes, turbines, sewers whatever. hope that helps

John C. Chien January 31, 2000 15:46

Re: part-time-cfd
(1). I think, the original question was rather simple and straightforward. Unfortunately, our answers tend to be more confusing. (2). The solution around the original problem is either to invest more time to learn the hardware, the software, and the CAD, or to hire someone else to help you. It can be either a full-time job, a temporary job, or a contract job. (3). Some large companies use "expert" while others use "specialist". (4). For a small company, it is at least the level of "director of technology". (5). "guru" is somekind of foreign name, not related to CFD. So, I have not heard of "guru" title being used in a company, officially. (6). But "fellow" is probably not an unusual title in a company. (7). In general, computer related technology is a very fast moving field, one must constantly reading and absorbing new information to keep himself up to date. It is not unique to CFD field . Since it is not possible to achieve the "true expert" level, we will have to accept the idea that it is possible to achieve the expert level in both the CFD and the water turbine design. (8). In this case, it is the "director of technology who is responsible for both the CFD and design technology".

Michael January 31, 2000 18:36

Re: part-time-cfd
Thanks John,

your first point is correct.

I want to show the background of my question: In our company there are two types of "experts" 1.) I call it cfd-expert. This contains the use of cfd-software in "my" area, hardware, a little bit programming, administration, in the moment we have external support for HP but perhaps we want to install linux and a new cad-system on pc's and so someone has to care for linux, someone should be able to install cad-updates and so on. (me ?) 2.) I call it "conventional"-expert: This contains the conventional design of water-turbines with a few formulas, pencil and paper and a lot lot of experience. This convential-expert designs the turbine, calculates it by hand and gives the geometry (perhaps) to the cfd-expert for exact calculation if he thinks it is necessary. He cares for the production and trial-runs.

I did up to now 90% the "cfd-expert" but my chief (an old "conventional-engineer") told me, that I should additionally care about the "conventional-expert". But I'm not sure, if this is possible in 24h/day . So I have to decide: devide me up into 2 parts with the risk of being a non-expert in both fiels (or become an epert in both fields) or concentrate in one area.


John C. Chien January 31, 2000 23:18

Re: part-time-cfd
(1). I understand that. It is a fairly typical situation. (2). I think, your product is water turbine. If I were you, I would take the opportunity to get into this conventional-expert line of work. This is because to effectively support the product design, one needs to have a thorough understanding of the product and the product design. In many cases, the CFD part failed because the CFD-expert did not have this thorough understanding of the product design. And modern design approach is "integrated" or "concurrent". (3). I am not talking about the actual time involved in the work. If it takes 24 hours, then it takes 24 hours. I am talking about the real understanding of the design approach. (4). The only possible problem is the communication between the CFD-expert and the Conventional-expert, when the CFD-expert is trying to learn the Conventional-expert part of the work. (4). So, I always say that for a company to survive and grow, everyone in the company must work as one company. If one reserves the key step from another engineer for some reasons, the company will fail. (5). And in many cases, in order to satisfy the ISO quality program, the company must have the written and approved design practice documents. So, the quality will be uniform. So, in the CFD part, you need to write down the step-by-step document to run a case, with sample input and the sample output. The same is true for the conventional-expert part. In this way, the product design integration will be easier to carry out. (6). My suggestion would be: Take care of the CFD part first, make sure that you understand every steps and have some documents and sample cases written. Then you can move on to the conventional-design part, and pick up the necessary knowledge. Then do the same to prepare the design precess documents. (7). Once you have gone through these steps, you can then worry about the actual work hours required to perform the actual work. (8). Some companies have policy to rotate the job assignment of a new engineer through several related departments for say 6 months each. The only purpose is the same. (9). If the job is routine, it is more efficient to work in the same field. But the engineer will eventually run out of interest in the same type of job assignment. (10). I would say, it is a good idea to let the engineer to work on the CFD and the conventional on the 50-50 basis. You can't eat just hamburgers 365 days a year.

clifford bradford February 2, 2000 13:01

Re: part-time-cfd
your boss makes a good point he thinks you must do more water turbine work because after all you're an engineer in a water turbine company not a computer scientist. i think you'll find that learning the w.t. design issues is not hard and your background in CFD which is first principles based will help you. also you'll find that there are some computational tools that can help you with the turbine design issues. after all if your company wants you to do more they should be willing to give you the tools to be more efficient. if they do this you will find that you can do more. if your company decides to switch from HP support to Linux then it doesn't seems fair for you to be required to take on the additional systems admin work. although that's exactly what will happen :( if so you should demand a big raise. they should hire a systems admin for that.

All times are GMT -4. The time now is 02:16.