[MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)

[CAEdevice]

A few teams have pulled the extension card, so you will have to wait a bit to see all the cars.

At the moment, even if I asked for the 48h extension, I can't exclude to use the same car of race02 and Race03.

[k.ko100v]

I am still struggling to set up my model. Still my cooling flow is negative value, which means that my body is open. Could it be because it is surface model, not solid?

According to MFlow or OF? What OF measures depends on the orientation of the triangles in your measuring surface. When you design the surface, the orientation should be consistent. MFlow just takes the absolute value of what OF measures.

So, the final value at the end of the simulation, so I guess this is The MFlow value.

I think i don't understand this triangle orientation. If you mean the coordinate orientation it is one and the same. Could it be because of the "mirror" function I use? First I build the left side of the car and mirror the right, and what I am seeing is that the Mflow is showing the value of the right HE surface value.

Edit:
Now I am seeing some difference in the surface structure on the .stl files



Regards,
Krasen

[variante]

Team Koldskaal and Variante noted the biggest rate of improvements and that's really impressive. Fur sure they haven't say the last word yet.

Yeah, Christian von Koldskaal has managed to find an impressive rear end downforce, as he does better than anyone else despite using a smaller wing. It's hard to imagine beating him before anyone really understands his secret.
Instead, i didn't improve much...my car was decent since the first race (i only had a problem with the .stl of the cooling surface), but i've never been able to cut on drag, my main problem.
Team Racing was the most impressive, i think.

Do you use accelerate the internal flow to generate suction behind the radiator? Or do you mix the internal and the radiator exhaust to get cleaner exhaust? Both? Seems interesting nonetheless. Also great strategy to draw attention away from what seems to be a completly new diffuser

The former. But the main principle is simpler: the bypass flow is essentially dirty air (coming from the suspensions,...) and instead of accelerating it outside of the sidepod (getting lift from its low pressure), i accelerate it on the inside surface of the sidepod. I'm not sure this is the best solution, but it's given me good improvement so far.
Yeah, there is also a conventional diffuser...nothing great...It gave me more efficiency, but also less downforce. Hopefully i can afford it, balance wise.

[rjsa]

I am still struggling to set up my model. Still my cooling flow is negative value, which means that my body is open. Could it be because it is surface model, not solid?

According to MFlow or OF? What OF measures depends on the orientation of the triangles in your measuring surface. When you design the surface, the orientation should be consistent. MFlow just takes the absolute value of what OF measures.

So, the final value at the end of the simulation, so I guess this is The MFlow value.

I think i don't understand this triangle orientation. If you mean the coordinate orientation it is one and the same. Could it be because of the "mirror" function I use? First I build the left side of the car and mirror the right, and what I am seeing is that the Mflow is showing the value of the right HE surface value.

Edit:
Now I am seeing some difference in the surface structure on the .stl files

https://imgur.com/r4FPEGc.jpg

Regards,
Krasen

You need both the hx and the control surface property meshed, I use 2x2cm squares all around. There’s a paper about that.

Edit: here: https://mantiumchallenge.com/porous-media-openfoam/

[LVDH]

I am still struggling to set up my model. Still my cooling flow is negative value, which means that my body is open. Could it be because it is surface model, not solid?

According to MFlow or OF? What OF measures depends on the orientation of the triangles in your measuring surface. When you design the surface, the orientation should be consistent. MFlow just takes the absolute value of what OF measures.

So, the final value at the end of the simulation, so I guess this is The MFlow value.

I think i don't understand this triangle orientation. If you mean the coordinate orientation it is one and the same. Could it be because of the "mirror" function I use? First I build the left side of the car and mirror the right, and what I am seeing is that the Mflow is showing the value of the right HE surface value.

Edit:
Now I am seeing some difference in the surface structure on the .stl files

https://imgur.com/r4FPEGc.jpg

Regards,
Krasen

Most software displays the two sides of an stl with different colors (Blender in a different shade).
"The final value" sounds like the OF log though. You can run this:

Code: Select all

MFlow.exe <case_folder> -pp -plots -offscreen

That will show you what MFlow thinks about your values.

You need both the hx and the control surface property meshed, I use 2x2cm squares all around. There’s a paper about that.
Edit: here: https://mantiumchallenge.com/porous-media-openfoam/

The hx tessellation does not matter, but have a good look at the link rjsa suggested.

[rjsa]

I didn’t know about the hx, thought it was sensible too.

[CAEdevice]

I have just submitted a car (CAEdevice_Race04_Sub01), but not received the confirmation from Dropbox.
Could the staff confirm that the upload has been completed?

Update: Dropbox confirmed the upload.
I don't have great hopes for this race: I finally summarised what I learnt in the last week in the car I submitted, but I will see the results only tomorrow.

[wb92]

Not only for CAEdevice this development was for learning. In my case bit harsh. There is still hope that my car might be balanced with keeping mighty BCD trio together (Balance, Cooling, Downforce). That will take more effort than expected... But still getting bit more experience.

Looking at the current grid I hope that I will reduce distance to guys fighting for podium - Team Koldskaal, Team Racing, Variante, CAEdevice (random order )

btw. is the force development curve over X available as clean data to import to excel?

[machin]

...Yeah, there is also a conventional diffuser...nothing great...

I’m sure, knowing your design skills, it’ll work well straight away... as long as you aligned it to the mandated MVRC floor part....

....the floor on EVERY car must have the standard portion coloured red below:

[variante]

I’m sure, knowing your design skills, it’ll work well straight away... as long as you aligned it to the mandated MVRC floor part....

Ohoh...
Well, maybe it's going to work even better...some vortex or something...

[LVDH]

I didn’t know about the hx, thought it was sensible too.

It is always good to use well tessellated geometry. In case of the hx flow measurement, I do not think you will notice a difference between a simple and a good hx box stl though.

I’m sure, knowing your design skills, it’ll work well straight away... as long as you aligned it to the mandated MVRC floor part....

Ohoh...
Well, maybe it's going to work even better...some vortex or something...

Mistakes happen. I found a violation on the CCE car. He should be ashamed.

[machin]

I found a violation on the CCE car. He should be ashamed.

If you’re not pushing the boundaries you’re playing it too safe, right?!

[LVDH]

So, the delayed cars have arrived. Unfortunately we did not get as many as in Japan, noticeably Baltic, TeamRacing and WWInc. did not submit a new car.
Anyway, this is the line up:

More images here:
https://mantiumchallenge.com/cars-mvrc-cota-2019/

[Ft5fTL]

Crap, i submitted the wrong zip file.

[LVDH]

Crap, i submitted the wrong zip file.

Did you at least fix your radiator issue?