[t.teschner]

I am currently trying to define the scope and work of a “virtual wind tunnel”. If you google for it you will come across an array of websites that allow you to upload a CAD file and then have a PDF report sent to you once the results are done (automatically generated based on the results). Now to me this sounds more like an automated CFD tool chain of pre/post processor and solver, but there is nothing really “virtual” about this, nor “wind tunnel” like (at least in my opinion, to me that sounds like CFD repackaged ...).

So my question to you is, what would you expect a virtual wind tunnel to be like? As far as I am concerned there are no right or wrong answers here. If you agree with the current approach of calling an automated CFD tool chain a virtual wind tunnel, that would also be helpful to know.

To me (and this may be considered in you answer), the word virtual offers new possibilities to be explored, which may or may not be useful, for example using a virtual reality headset for 3D post processing (but would that be sufficient to grant it the attribute virtual wind tunnel?), or should there be some form of artificial intelligence involved (as it seems to be the new hype and everyone doing “virtual” or “digital” products relies on it)?

Any insights as to what you think on that topic would be appreciated.

[sbaffini]

Originally Posted by t.teschner

I am currently trying to define the scope and work of a “virtual wind tunnel”. If you google for it you will come across an array of websites that allow you to upload a CAD file and then have a PDF report sent to you once the results are done (automatically generated based on the results). Now to me this sounds more like an automated CFD tool chain of pre/post processor and solver, but there is nothing really “virtual” about this, nor “wind tunnel” like (at least in my opinion, to me that sounds like CFD repackaged ...).

So my question to you is, what would you expect a virtual wind tunnel to be like? As far as I am concerned there are no right or wrong answers here. If you agree with the current approach of calling an automated CFD tool chain a virtual wind tunnel, that would also be helpful to know.

To me (and this may be considered in you answer), the word virtual offers new possibilities to be explored, which may or may not be useful, for example using a virtual reality headset for 3D post processing (but would that be sufficient to grant it the attribute virtual wind tunnel?), or should there be some form of artificial intelligence involved (as it seems to be the new hype and everyone doing “virtual” or “digital” products relies on it)?

Any insights as to what you think on that topic would be appreciated.

Understanding the hype around some terms and what is actually implied by them is indeed difficult if you haven't been on the other side. As I worked for a company that tried to sell CFD Apps, including such a "virtual wind tunnel", here are my two cents:

1. First of all, remember that this usually is hype, marketing, there is someone trying to sell something.

2. Depending on who is the target of the sell, the terminology has to change.

3. If you ever tried to explain CFD to anyone you know that is not into the field, you know it is impossible to explain for those not in science, and very difficult for those in science but not related field.

4. It is impressive how effective the terminology "virtual wind tunnel" is in delivering a very accurate description of CFD to non experts. Apparently, a lot of people know, conceptually, what a wind tunnel is, in the sense of what it is used for, and can filter out most details from virtual... it is on the computer (they don't really care if it is virtual in the sense of VR or anything else). Apparently, people also understand "app" better than software or computer program.

5. This tells you that what they are trying to sell with "virtual wind tunnel" is CFD to non experts, but of course it still is just packaging of some CFD.

The unfortunate side of the story is that, in order for the non experts to really undertand the product, than it really has to resemble a wind tunnel, at least from the GUI. So, in the best case, what is really sold is a full fledged CFD solver limited to use just wind tunnel like scenarios (i.e., you always have an inlet and an outlet, etc.). In the worst case you may also have some "wind tunnel" hardcoded in the source code here and there, just to make everything super hard and useless.

[t.teschner]

I think your answer is largely consistent with my observations (from a commercial view point) and in the environment that you've described (i.e. selling it t non-technical experts) it makes sense. It is interesting though what different answers you get, speaking to CFD developers I have gotten very different views. So there doesn't really seem to be any consensus as to what the term should mean, which may then render it bit useless ... Anyways, thanks for your thoughts, it is much appreciated!

[sbaffini]

Originally Posted by t.teschner

I think your answer is largely consistent with my observations (from a commercial view point) and in the environment that you've described (i.e. selling it t non-technical experts) it makes sense. It is interesting though what different answers you get, speaking to CFD developers I have gotten very different views. So there doesn't really seem to be any consensus as to what the term should mean, which may then render it bit useless ... Anyways, thanks for your thoughts, it is much appreciated!

Unfortunately I think I can't have anymore my own genuine view on the topic, deprived from the commercial point of view, because I first heard of it in that setting. But, I guess, Virtual in the sense of VR would totally make sense, lexically speaking.

If Virtual, in the sense you gave to the word, is something interesting and what it should actually include as technology, I've come to the conclusion that they are unpredictable answers.

I see use cases for a lot of these technologies, but the point is how much productivity is in them to justify a certain cost? Or how much discovery can they promise?

I have doubts about any positive metric existing at all.

[LuckyTran]

I also would immediately assume CFD upon hearing "virtual wind tunnel," whether it be a CFD service done by a person or automated AI.

The thing is... a wind tunnel is a device used for testing purposes and measuring some performance test. We don't build a car or airplane and then show it off to our friends in a wind tunnel. If you wanted to show it off, it'd be in a showroom. If you just wanted to see what something looked like from your desk, that would just be a model or a rendering. You wouldn't say, "I've put it in a wind tunnel so you can see what it looks like." So that's where my expectations put me.

I tentatively agree we should be more careful how we use virtual now that VR is prevalent. But when it really matters, people can quickly recognize the lexical difference between virtual and VR. As an example: if I say "it is virtually impossible to travel faster than light." One would not ordinary assume that the task I am assigning is impossible only on VR.

[t.teschner]

well, that is the point, isn't it. the word "virtual" has so many meanings (in different contexts) that it becomes difficult to find an appropriate definition for it in the term "virtual wind tunnel" (hence the whole point of this discussion). So for some (experienced) CFD users / developers, virtual just translates to VR (or AR (augmented reality)) but I have to agree with Paolo here, that there is a use case for VR here but it is questionable if it can and will offset the hardware / development cost (another reason for this discussion). I have not found an interesting use case for 3D post processed VR results other than showing non-technical people what we can see and visualise with CFD. But simply having a "fancy" way of visualising may not be a viable reason to jump onto the virtual hype I guess ...

[LuckyTran]

Another very popular product that is all the rage nowadays is a Virtual Private Server which has nothing to do with VR.


In my opinion, VR is just so niche and so well-defined that it's just easier to slap the VR onto anything when you want it to be known involves VR and to not get it mixed up with something else. Same with AR.

[t.teschner]

and what would a virtual private server entail? just cloud-based computing?

[LuckyTran]

Nothing to do with cloud computing either. A virtual private server involves an internet host. The host will own a physical computer but allow (several) customers to each run their own OS with their own dedicated hard disk space and memory and so on. It's very similar to a virtual machine where you can run an OS within an OS. A good example of this is the popular VMware. Any network admin person probably deals with virtual machines daily. The majority of websites are actually hosted on virtual private networks. You can think of many websites, but how many internet computers do you know of that hosts the internet?

There's also Virtual Private Networks (VPN's) which is essentially a non-physical re-routing of network traffic through network tunnels. Combined with encryption, these are used to hide activity. Nowadays these are being marketed to home users for privacy reasons. Historically, they were used by pretty much every large business for security reasons.

So to double-down on my argument, there's just sooo many common products that utilize Virtual in them while having nothing to do with VR that I don't see the meaning of VR being a forced implication whenever Virtual appears. That is not to say that VR is anything knew and that is why the association is not there. I've known VR all my life. We just always called it VR.

[t.teschner]

yes, it touches upon the inflated use of the word virtual here ... but I guess that is outside the scope of what a virtual wind tunnel ought to be.