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warren
human power expert

USA
6114 Posts

Posted - 05/11/2015 :  19:36:05  Show Profile  Visit warren's Homepage  Reply with Quote
Very cool. I designed this in about 10 minutes from scratch. That is actually a scale me in there, with a SWB bike with all frame tubes, and the body which looks pretty darn good. Nice job Wayne!



And the software tells me:
Length: 102.6 inches
Width:20.9
Height:30.9
Frontal area:459 sq in.

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shooky56
recumbent guru

USA
545 Posts

Posted - 05/12/2015 :  10:14:14  Show Profile  Reply with Quote
Thanks Warren and Steve. Didn't manage to get ANY import into AutoDesk yet although I haven't worked it too hard. If anybody has a CFD app they like and knows if it'll take stl imports, let me know. My main effort will be to create an "exterior mesh". Maybe that isn't needed perhaps the CFD generator is smart enough to only contact the exterior portions.

Would be nice to slap a canopy on somewhere. About 10,000 words ago I mentioned I had no plans to add a canopy designer and still don't but still it would be nice to have the complete package before porting it to a CFD app.

Warren has been working with me a bit to debug a couple of issues. We have one fairly minor one left that I cannot repeat.

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warren
human power expert

USA
6114 Posts

Posted - 05/12/2015 :  11:23:32  Show Profile  Visit warren's Homepage  Reply with Quote
CFD analysis is in the deep end of the pool where I feel I may drown.

Here are some open source CFD tools that may work. I have not tried any of them.

http://su2.stanford.edu/index.html
http://www.openfoam.org/

-Warren.
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Speedy
recumbent guru

USA
882 Posts

Posted - 05/12/2015 :  12:08:53  Show Profile  Reply with Quote
Sadly ...
neither one of these support a .stl import

this one does
http://www.raczynski.com/pn/fluids.htm

going from a .stl to a mesh shouldn't be too big a problem
pretty sure meshmixer can do it ...

oops ... meant to say meshlab
blender might work as well


quote:
Originally posted by warren

CFD analysis is in the deep end of the pool where I feel I may drown.

Here are some open source CFD tools that may work. I have not tried any of them.

http://su2.stanford.edu/index.html
http://www.openfoam.org/

-Warren.



Steve Delaire

http://molten3d.blogspot.com

Edited by - Speedy on 05/12/2015 12:19:02
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shooky56
recumbent guru

USA
545 Posts

Posted - 05/12/2015 :  13:38:40  Show Profile  Reply with Quote
Thanks men. Mesh or STL exports aren't hard but I really should work with the end tool at the same time to check if it's going in right. Starting to look like a long distraction though.
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Speedy
recumbent guru

USA
882 Posts

Posted - 05/12/2015 :  14:29:54  Show Profile  Reply with Quote
Netfabb and FreeCAD have robust .stl checkers

If the model passes muster in either then it will manufacture in any other software



Steve Delaire

http://molten3d.blogspot.com
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neil.carter
Starting Member

18 Posts

Posted - 05/13/2015 :  04:53:16  Show Profile  Visit neil.carter's Homepage  Reply with Quote
So I use Autodesk Flow Design and that inputs the STL binary file with no problem
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shooky56
recumbent guru

USA
545 Posts

Posted - 05/13/2015 :  16:38:35  Show Profile  Reply with Quote
Neil: Thanks I am now using AutoDesk Flow Design also. See several in here talking about scaling in another product. Although AFD doesn't scale it does rotate the axis and other products can scale. But I can scale also. What I'm going to do is make my export do life sized models with a default load in AFD and default axis orientation.

If you import and scale your model in HPV Designer, I'll export scaled and rotated so it's right sized and oriented also (for AFD).

Culling the boundaries is mathematically complex and would take a long time. For now I'll just export the shell.



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shooky56
recumbent guru

USA
545 Posts

Posted - 05/15/2015 :  07:17:28  Show Profile  Reply with Quote
Just a quick update. All this CfD stuff motivated me to add an export and I'm still working that. Do export the shell properly. The export loads into AutoDesk's Flow Design properly and oriented correctly (althought they have tools to swap the axis). Autodesk seems to think width and height are swapped but that's OK, it's oriented correctly to the ground plane.

Short video showing a long run time 3D hi-rez analysis of a shell very close to what I will make. It is devoid of unnecessary clutter like wheels and places for human heads and such but the results are interesting nonetheless. W/O rolling drag and pressure drag from wheels and canopies, it's 59W for 30 mph.

https://youtu.be/9blvX5zLGSA

My current effort is toward producing a boundary "shell" that includes the wheels and canopy. The idea would be you design your canopy elsewhere, import it, manually position it as you need, then export the entire assembly.

You end up with a complete stl file capable of importing to Flow Design for analysis.

Not sure I'll complete this part but at some point I'll wrap this up again and deliver it.


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Speedbiker
human power expert

USA
3755 Posts

Posted - 05/15/2015 :  08:12:50  Show Profile  Reply with Quote
Did you see the previous discussion about placing a mirror image of your shape under it to approximate the effect of the ground?
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shooky56
recumbent guru

USA
545 Posts

Posted - 05/15/2015 :  10:08:15  Show Profile  Reply with Quote
I did. Apparently Flow Design's most recent rendition considers a ground plane. The pressure regions certainly ball up at the lower nose like it, I suspect, it really does and vortices like to form on the rear underside, again like my unreliable intuition would think it would.

As for the mirror image, I don't seem to have an option (or haven't figured it out) how to move the model into completely free air. A mirror image would mandate me figuring that out.

HEY! Anybody have the mesh of a canopy they'd like to give me?
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neil.carter
Starting Member

18 Posts

Posted - 05/15/2015 :  12:39:24  Show Profile  Visit neil.carter's Homepage  Reply with Quote
feel free to play with the one i sent you :-)

Have a couple more if you want
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Filip Arvidsson
Starting Member

Sweden
27 Posts

Posted - 05/15/2015 :  13:59:12  Show Profile  Reply with Quote
I´m having some trouble getting started. The default layouts are all jumbled and even though I reset them and export there´s no change in the shell.
When I try to export the rider I get "System.Collections.Generic.KeyNotFoundException" and when I closed it down I got "The program needs flash.ocx, not included in this version of Windows.".
I tried reinstalling flash but no luck. My OS is Win 7 64-bit.



If anyone got some idea I would be grateful because the software seems great!
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shooky56
recumbent guru

USA
545 Posts

Posted - 05/15/2015 :  14:45:32  Show Profile  Reply with Quote
Filip email me if you can get my email from the site. Let me know.

Put something in the subject about HPV Design so I don't auto delete it.

The flash player is for the youtube videos and running setup.exe is supposed to bootstrap the dependencies (MicroSoft distributes the ocx of which you get the error message, probably the ocx was from Adobe).

A couple things have happened on installs that I've not seen on my test installs (have two other machines). One is multiple copies. This is supposed to be possible if you install for everyone once and only me once but, after that it was supposed to overwrite those copies and it always has for me for me (I've probably done 80-120 installs, sometimes from scratch after deleting all traces, sometimes over the top of old ones).

However we've had at least one issue on a PC with an SSD that held old data (that was his guess and I agree it's as good a guess as any). They had 6(?) simultaneous installs. I've installed literally 100 times over old versions and only had two installs when I accidentally install "just me" once.

But try this:

--click The Windows button->Control Panel->Uninstall a program and remove all copies of HPV Shell Designer.

--open a Windows Explorer and type %appdata% in the address box and press [Enter]. Look for a directory called "HPV Shell Design" and delete the entire directory.

--restart your PC and try reinstalling. Click the setup.exe (not the msi) to install. I never test this for "just me" so if it's OK on the PC you use try to always do "everyone".

See if that gets you somewhere. I know for sure it installs the .Net Framework from MicroSoft "as needed" but not sure about the flash player (also MicroSoft).

A more detailed thing says you're getting all the bitmaps but not loading the widget data. It is the <so-n-so>.frame file that holds the information about where to put those frame parts.

One more thing, the export from frame or rider designer does not change the shell only other stuff the shell is supposed to enclose. You have to manually warp the shape to engulf all body parts and frame parts.

Good luck and, again, if you can get me email feel free. We can even hook up on Ventrillo we maintain a family server and I have family on there 24-7 WE'RE A FRIENDLY BUNCH! no cursing, we have grand babies on there sometimes.

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shooky56
recumbent guru

USA
545 Posts

Posted - 05/15/2015 :  14:49:15  Show Profile  Reply with Quote
Oh and if you browse back a bit I gave links to the video instructions in here. The flash player error probably only comes when you try to click a help video? Maybe you could watch some of the help videos straight through your browser (bypassing the Shockwave).

Wouldn't fix the no internal video thing but maybe get you going.

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shooky56
recumbent guru

USA
545 Posts

Posted - 05/15/2015 :  14:54:17  Show Profile  Reply with Quote
Looking more at your pictures, I'm sure the project files are not loading for some reason. Or not loading properly anyway. Try watching some of these videos and see if you can save your own copies.

I do know friends of mine who have delivered international software have had problems with directory location changes.

overview: https://www.youtube.com/v/9AIUniwPMt0
frame: https://www.youtube.com/v/0mqxhcJC2Ps&feature=youtu.be
rider: https://www.youtube.com/v/lPxD-GkDdeU&feature=youtu.be
shell: https://www.youtube.com/v/WklUderxItQ&feature=youtu.be
output: https://www.youtube.com/v/o5Afd4IE7Jo&feature=youtu.be
printing: https://www.youtube.com/v/SJ5zj0n5YGo&feature=youtu.be

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warren
human power expert

USA
6114 Posts

Posted - 05/15/2015 :  15:43:57  Show Profile  Visit warren's Homepage  Reply with Quote
Hi Filip,

I uploaded the latest version 1.3.8. This version fixes the selection issue you found in the frame designer and it also allows for taller people in the rider designer.

http://www.recumbents.com/wisil/download/wayne/HPV%20shell%20Designer%20Installer.msi
http://www.recumbents.com/wisil/download/wayne/setup.exe

First run the uninstall from add/remove programs

Download both files to the same directory and run setup.exe

-Warren.

Edited by - warren on 05/15/2015 15:46:48
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warren
human power expert

USA
6114 Posts

Posted - 05/15/2015 :  16:03:17  Show Profile  Visit warren's Homepage  Reply with Quote
Animated GIF ( takes a while to load)

Edited by - warren on 05/16/2015 05:40:23
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shooky56
recumbent guru

USA
545 Posts

Posted - 05/15/2015 :  17:30:14  Show Profile  Reply with Quote
Interesting! Hmmm. new canopy-less racer in the works? LOL. Hey ya get that where ya like it, send it to me (zip the entire directory just to be sure) and I'll run CFD on it.

Not going to post pictures but I am exporting my wheels and my rear axle to AutoDesk and did not wait for it to settle, it had the CfD at .13 which was lower than w/o the wheels which I found kind of amazing. My guess is, if I'd have waited a couple hours it would have settled around .14 or .15, it often goes low in the first 10 minutes then slowly works its way back up a back.

Despite the lower CfD the total drag went up about 35%, that's still neglecting the canopy and the fact the wheels are spinning. The shell in question we're still at 80W for 30 mph. Lord these things are going to be fun! To quote Tom Cruise before insanity set in, "I have the need for speed!".

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shooky56
recumbent guru

USA
545 Posts

Posted - 05/15/2015 :  21:51:41  Show Profile  Reply with Quote
With the wheels exported, I worked on figuring out the ground plane. There was a "help post" about turning off the ground plane (a switch I have yet to locate) but what I did figure out was how to shift the wind tunnel (which is huge compared to the model size, probably 100x the cross-section). At any rate with the ground plane shifted properly I am now running a long term CFD, I'll let it run overnight (at hi-rez these take a very long time and my machine is pretty muscled up too).

Here's a little better video of the sim I'm running now.

Autodesk's Flow Design running against Shook2 shell.
https://youtu.be/2Nrq0-LVdHU

Power requirements (only post the calculations lest I'm screwing up somewhere, man this seems low).

At 30 mph: (.044lb x 32f/s2 x 44f/s) /550 ft-lb/s2 = .113 HP
.113 HP x 746 W/HP = 84W

Short cheat for 60 mph; 84W x 8 = 672W

Errors:
(1) no canopy
(2) no spinning wheels
(3) I'll have some more "junk" hanging outside this, in particular some of the cluster (FWD) will protrude out the shell.
(4) ducting and louvers.
(5) the rear axle plate.

No idea how much the above adds but one hour into the simulation w/o those things above the Cd is .102. The little lines look like they'll converge around .106.
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shooky56
recumbent guru

USA
545 Posts

Posted - 05/16/2015 :  04:41:03  Show Profile  Reply with Quote
After an all night run the drag graph showed "stabilized" this morning.

If the model is accurate, AutoDesk's publications claim 6% average agreement with real tests. The results ran a bit low for low-rez and a bit high at high rez. This is hi-rez.

Boy it'd be nice to have a canopy on it to get a real idea. Doesn't look like there's anything I can do about the non-rotating wheels except add fairings to them (would help accuracy some I guess).

The wheels shown are discs with flat surfaces like the old wagon wheels, that's not helping.

[URL=http://s1372.photobucket.com/user/shooky56/media/Recumbent%20Postings/CFD%20Shook2%20-%2030mph%20-%20200rez%20-%203D%20-%20Press%20-%20DP%20-%20Iso_zps6fv3uh6h.png.html]
[/URL]

[URL=http://s1372.photobucket.com/user/shooky56/media/Recumbent%20Postings/CFD%20Shook2%20-%2030mph%20-%20200rez%20-%203D%20-%20Vel%20-%20DP%20-%20Iso_zpsv9hivtir.png.html]
[/URL]

[URL=http://s1372.photobucket.com/user/shooky56/media/Recumbent%20Postings/CFD%20Shook2%20-%2030mph%20-%20200rez%20-%203D%20-%20Velo%20-%20DP%20-%20FlowLines_zpszprsdb6q.png.html][/URL]
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shooky56
recumbent guru

USA
545 Posts

Posted - 05/16/2015 :  07:13:54  Show Profile  Reply with Quote
Filip and I worked together this morning to find a solution for the problem he was seeing. We didn't figure out the shockwave thing (nor did we try as he can view them from here) but the problem was a Cultural setting in Windows.

There are practices to follow for producing Culture tracking software but that's about all I know. With my primary client having been exclusively US targets I finished my career blissfully ignorant of the details needed to target other regions.

Here's what Filip did, he set his machine to be English and to use a "." for the decimal separator. The English may not matter but definitely the comma thing is a problem.

Windows->Control Panel->Clock, Language and Region->Region and Language

On that popup he selected the Formats tab then [Additional Settings]

On that page he changed the decimal symbol from a comma (,) to a period (.).

It all worked and I don't think he had to reboot.



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shooky56
recumbent guru

USA
545 Posts

Posted - 05/16/2015 :  08:26:16  Show Profile  Reply with Quote
...and yet another. Export the head. The most interesting view IMO was the ISO display of pressure. The green cloud is ambient pressure (sea level in this case).

Adding the head added 50% more total drag and it's pretty evident why. That large iso close shows the region that this thing effects with my noggin poking poking out into the slipstream. Looks more like an air brake.

Believe this illustrates the advantage of a canopy or, at a minimum, a windshield.

[URL=http://s1372.photobucket.com/user/shooky56/media/Recumbent%20Postings/CFD%20Shook2wHead%20-%2030mph%20-%20200rez%20-%203D%20-%20Pres%20-%20Iso%20-%20FlowLines_zpsdkkshroa.png.html]
[/URL]
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shooky56
recumbent guru

USA
545 Posts

Posted - 05/16/2015 :  14:54:21  Show Profile  Reply with Quote
As a former programmer of serious mathematical analysis tools myself for the military, I know the value of seeing some confirmation that you are doing it right... or at least "close to right". There is no doubt in my mind that my prior drag numbers are optimistic because I know there are "things missing". Most of it, however is not missing.

But I still needed proof. So I added a second leg... exported it put it on the default upright bike (also completing the frame) and exported all the above.

When all was said and done, I came up with a .53Cd and a net force of 0.201 lbf.

Comparing the power requirement (.201 lb->384W) to the link below (which said 397W) I found that close agreement. Only looking for ballpark agreement and was happy to see much better than ballpark.

Cycling Power: http://www.americanroadcycling.org/TheBook/PowerToWeightCalculator.aspx?frm=RaceCategoryTableCaptionAbove

The following dissertation on TT position Cds also added confirmation as they had Cds between .53 and .54 for similar data.

TT Cd analysis: http://dc.uwm.edu/cgi/viewcontent.cgi?article=1031&context=etd

[URL=http://s1372.photobucket.com/user/shooky56/media/CFD_Standard_TT_Upright_Position_69i_Rider-30_%20mph-400rez-3D-Press-DP-ISO-2_zpsrewma6i8.png.html]
[/URL]


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warren
human power expert

USA
6114 Posts

Posted - 05/16/2015 :  18:00:33  Show Profile  Visit warren's Homepage  Reply with Quote
Very cool!
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