[MVRC] Mantium Virtual Racecar Challenge 2016

[Alonso Fan]

I am a bit sick so I am slow today. You will hopefully receive the flow visualizations today. But while your car looks very good, somehow no parts work properly, although you have improved them all. You also have a slightly improved cooling flow but not enough for it show with the engine power not having decimal places in my table.
One good thing though is that although you scored last position in both races you are not last in the championship! So keep those improvements coming.

My suggestion is to google for radiator duct design or do what RicME did last season and ask the forum to help him. It did wonders to his car.

Thanks, and hope you get better soon

[RicME85]

That sounds like I asked the forum to design my challenger when it was a combined effort to try and understand a KVRC car and the basics of making changes with CFD that was shared for all.

When are we likely to see the new rules?

[LVDH]

That sounds like I asked the forum to design my challenger when it was a combined effort to try and understand a KVRC car and the basics of making changes with CFD that was shared for all.

Yes, sorry I did not mean to imply the others did the work. But the approach of asking and sharing results was good and worked.

[cdsavage]

The updated rulebook is available on the MVRC site: http://mantiumchallenge.com/mvrc-the-rules/

These are the changes:

• Removed rules around cooling inlets/outlet surfaces and the duct. Now you only need to worry about how to achieve the required airflow through the heat exchanger without any restrictions on inlets and outlets.
• Heat exchanger: we now require that you also submit the front face of the heat exchanger moved rearwards by 50mm (i.e. a face that sits in the middle of the heat exchanger). You should continue to submit the heat exchanger extrusion as before.
• There are a couple of new restrictions on placement of engine intake and engine exhaust surfaces, but these shouldn't affect most entries.
• Engine exhaust surfaces can no longer be significantly larger than the minimum, they must be between 5000 and 5200 mm^2
• Minor change in wording to K3.4

[RicME85]

Yeah it did, I enjoyed the back and forth of the discussions and trying different things out.

[LVDH]

Wich surface (inlet/outlet) is used to measure the cooling flow (the values are a bit different sometimes)? I have chosen safe settings for the first two races (3.1-3.2 m^3/s), but the competition is getting harder and I have to refine the car.

I hope this picture explains how the stl triangulation affects the results measured by you guys:

I always made the mid surface myself using a uniform 10mm mesh.
If you need to know more you can find it here:
http://mantiumchallenge.com/measuring-p ... edia-flow/

[etsmc]

Will there be a new version of mantium flow?

[LVDH]

There was an update a few days ago, so if you missed that you can indeed get a new version. More important is that HP-Racing updated their GUI today. There were some issues with usability so it could be easier to use now. It is now available on the challenge page.

[etsmc]

So where do we put the face in the middle of the hx in relatio to the input_file folder structure?

[LVDH]

monitoring_surfaces

[etsmc]

how much of a difference does the fine triangulation mesh have on results?

[Alonso Fan]

Wich surface (inlet/outlet) is used to measure the cooling flow (the values are a bit different sometimes)? I have chosen safe settings for the first two races (3.1-3.2 m^3/s), but the competition is getting harder and I have to refine the car.

I hope this picture explains how the stl triangulation affects the results measured by you guys:
http://mantiumchallenge.com/wp-content/ ... g_flow.png
I always made the mid surface myself using a uniform 10mm mesh.
If you need to know more you can find it here:
http://mantiumchallenge.com/measuring-p ... edia-flow/

This will be a problem for me once I have wflow working because I use Sketchup. Sketchup likes to choose its own way of deciding how planar surfaces are constructed internally. I hope Rich has a clever workaround

[LVDH]

As I said, as soon as you reach 10mm the results do not substantially change with smaller triangles any more. Also the mesh should be very uniform. Have a look at the triangles in the picture. If it spans from the very left to the very right you are measuring a lot of different velocities with one triangle.
Remeshing an stl is for example possible with Meshlab or Blender which are both free.

[etsmc]

sorry, i did not mean smaller than 10mm but larger, for example, the inlet you show in the image what are the results as it is and what would they be if it was 10mm triangles?

I will have to look at doing the same as Alonso fan as I too use SketchUp so will have to see how to do it with Meshlab.

[LVDH]

Not sure about the exact numbers right now but the poorly triangulized surfaces showed something in the range of 2m³/s and the good one 1m³/s, so in this case it was very misleading. Other teams had more luck and their and my surfaces showed very similar results but I would not relay on such kind of luck,