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

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

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So, guys, in case you missed them, here are some interesting pics from Caterham that have been posted in another thread of F1Technical (which is one of the reasons why i love this website):
Image
Image
Image

And this one might come particularly in handy to those who are lacking some cooling performance. I would not reccommend to tilt the radiator so much (mine is 45°), but the intake shape is extremely interesting:
Image

I need you to study these images and beat CAEdevice! :lol:

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

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variante wrote:
24 Sep 2019, 18:24
I need you to study these images and beat CAEdevice! :lol:
You don't need to study, you only need to do smaller steps... on the contrary I need to study to make bigger steps!
Last edited by CAEdevice on 24 Sep 2019, 18:47, edited 1 time in total.

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

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variante wrote:
24 Sep 2019, 18:24
https://i.imgur.com/J0TEoBv.jpg
I wonder how they could manage cooling with so small inlets and outlets (and dirty outlet ducts).

Modern F1 also have a third HX above the engine (I think it is the intercooler). It would not be difficult to simulate 8)

(In that case I think that it would contribute to the 3,0 m2/s flow, no need to add additional cooling flow).

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jjn9128
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Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)

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Damn someone's copied my car #-o
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

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jjn9128
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Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)

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CAEdevice wrote:
24 Sep 2019, 18:46
variante wrote:
24 Sep 2019, 18:24
https://i.imgur.com/J0TEoBv.jpg
I wonder how they could manage cooling with so small inlets and outlets (and dirty outlet ducts).

Modern F1 also have a third HX above the engine (I think it is the intercooler). It would not be difficult to simulate 8)

(In that case I think that it would contribute to the 3,0 m2/s flow, no need to add additional cooling flow).
For one the inlets are a bit further downstream of the front axle. The suspension members can have a little incidence to align them to the front wing wake so they don't separate. They generate much lower pressure under and behind the car which draws air through the sidepods.

Depends on the team, I think Mercedes teams definitely have the intercooler there (see the Racing Point nudes from Monza). Ferrari have a much smaller airbox so I'm not even sure if they have gearbox oil cooler above the gearbox.
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

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

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jjn9128 wrote:
24 Sep 2019, 19:07
The suspension members can have a little incidence to align them to the front wing wake so they don't separate.
Once I was looking at the Haas (I don't rember if it was 2017 or 2018) but I clearly had the impression that the incidence was negative. I can't explain how they can avoid separation (I have separation even considering that are suspension profiles are neutral).

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jjn9128
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Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)

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CAEdevice wrote:
24 Sep 2019, 19:12
jjn9128 wrote:
24 Sep 2019, 19:07
The suspension members can have a little incidence to align them to the front wing wake so they don't separate.
Once I was looking at the Haas (I don't rember if it was 2017 or 2018) but I clearly had the impression that the incidence was negative. I can't explain how they can avoid separation (I have separation even considering that are suspension profiles are neutral).
You have separation because of the front wing upwash - which effectively creates a nose up incidence on the suspension.
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

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jjn9128
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Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)

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variante wrote:
24 Sep 2019, 18:24
So, guys, in case you missed them, here are some interesting pics from Caterham that have been posted in another thread of F1Technical (which is one of the reasons why i love this website):
https://i.imgur.com/7Cpfhuo.jpg
https://i.imgur.com/XSsL8mA.jpg
https://i.imgur.com/twVU956.jpg

And this one might come particularly in handy to those who are lacking some cooling performance. I would not reccommend to tilt the radiator so much (mine is 45°), but the intake shape is extremely interesting:
https://i.imgur.com/J0TEoBv.jpg

I need you to study these images and beat CAEdevice! :lol:
My cooling duct... looks familiar... :lol:
Image
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

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

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variante wrote:
24 Sep 2019, 18:24
So, guys, in case you missed them, here are some interesting pics from Caterham........ I would not reccommend to tilt the radiator so much (mine is 45°), but the intake shape is extremely interesting:
https://i.imgur.com/J0TEoBv.jpg

I need you to study these images and beat CAEdevice! :lol:
Mine are very similar too...

Do you think the cooling fins on their heat exchangers are:

1, at 90 degrees to the front face of the H-Ex (so the air has to go through a sort of ‘S’ shaped path through the H-Ex) or

2, do you think they’re aligned parallel with the floor so the air flows more or less horizontally through the H-Ex?

Which assumption does Mantium Flow use? If it’s arrangement 2 that would explain why angling the heat exchanger past 45 degrees has a detrimental effect on flow...

....Looks like I might need to redesign mine....
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rjsa
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Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)

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Barge boards are supposed to ho high res?

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

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jjn9128 wrote:
24 Sep 2019, 21:23
My cooling duct... looks familiar... :lol:
Hey, that's pretty much it!
Even though, your intake is longer. Probably it won't make actual difference, but a shorter one should restrain energy losses, right?

machin wrote:
24 Sep 2019, 21:26
Do you think the cooling fins on their heat exchangers are:

1, at 90 degrees to the front face of the H-Ex (so the air has to go through a sort of ‘S’ shaped path through the H-Ex) or

2, do you think they’re aligned parallel with the floor so the air flows more or less horizontally through the H-Ex?

Which assumption does Mantium Flow use? If it’s arrangement 2 that would explain why angling the heat exchanger past 45 degrees has a detrimental effect on flow...
I think in F1 they still lie within case 1. In fact, a couple of years ago i saw a Ferrari with winglets behind the radiator which were supposed turn the flow back to horizontal.

MFlow does something similar to case 1 too (you can see that with SurfaceLIC), but you don't have to bother alligning the flow to the "fins" (i think) because there are no fins.

machin wrote:
24 Sep 2019, 21:26
If it’s arrangement 2 that would explain why angling the heat exchanger past 45 degrees has a detrimental effect on flow...
I found big angles worse mostly because it's hard to manage the outlet flow. You'd have to turn that flow hard back to horizontal without big backpressure.

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

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machin wrote:
24 Sep 2019, 21:26

Do you think the cooling fins on their heat exchangers are:

1, at 90 degrees to the front face of the H-Ex (so the air has to go through a sort of ‘S’ shaped path through the H-Ex) or

2, do you think they’re aligned parallel with the floor so the air flows more or less horizontally through the H-Ex?

Which assumption does Mantium Flow use? If it’s arrangement 2 that would explain why angling the heat exchanger past 45 degrees has a detrimental effect on flow...

....Looks like I might need to redesign mine....
Very good question.

I have been thinking about the fins for two years.

MVRC HXs are modeled as porous media, with Darcy coefficients referred to a local coordinate system in order to simulate fins that are NORMAL to the HX (and measurement) surface. Last year I could never make rotated HXs work (HXs were more efficient if normal to the movong direction of the car) ... so I had the same doubts.

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

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variante wrote:
24 Sep 2019, 21:49
you don't have to bother alligning the flow to the "fins" (i think) because there are no fins
There are no fins but the HX works like they are there: the porous media parameters are not isotropic (actually they are transversely isotropic, but I am not sure about my English translation of "trasversalmente isotropo").

I don't remember the name of the txt file I modified once to simulate an "arrow" layout of the HX (not allowed by the rules unluckily), so let's wait LDVH for more information.

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jjn9128
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Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)

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variante wrote:
24 Sep 2019, 21:49
Hey, that's pretty much it!
Even though, your intake is longer. Probably it won't make actual difference, but a shorter one should restrain energy losses, right?
The length is a compromise with the undercut. I've also been toying with the idea of turning vanes behind the heat exchangers, great minds and all that :lol: I'm worried about file size with lots of thin elements though.
#aerogandalf
"There is one big friend. It is downforce. And once you have this it’s a big mate and it’s helping a lot." Robert Kubica

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wb92
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Re: [MVRC] Mantium Virtual Racecar Challenge 2019 (Grand Prix Cars)

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There's plenty of interesting stuff going on there while I was forcing my car's rear to work finally... I need an elephant on the rear axle to find the balance if anyone is interested 'how it's going' ;)

So let me write some words about the HX topic
CAEdevice wrote:
24 Sep 2019, 21:55
machin wrote:
24 Sep 2019, 21:26

Do you think the cooling fins on their heat exchangers are:

1, at 90 degrees to the front face of the H-Ex (so the air has to go through a sort of ‘S’ shaped path through the H-Ex) or

2, do you think they’re aligned parallel with the floor so the air flows more or less horizontally through the H-Ex?

Which assumption does Mantium Flow use? If it’s arrangement 2 that would explain why angling the heat exchanger past 45 degrees has a detrimental effect on flow...

....Looks like I might need to redesign mine....
Very good question.

I have been thinking about the fins for two years.

MVRC HXs are modeled as porous media, with Darcy coefficients referred to a local coordinate system in order to simulate fins that are NORMAL to the HX (and measurement) surface. Last year I could never make rotated HXs work (HXs were more efficient if normal to the movong direction of the car) ... so I had the same doubts.
machin points:
1. in general air-fluid radiators/HX have a core with fins normal to the flat frontal surface, although some F1 teams (I guess Mercedes) have this frontal area curved.
2. if that would be the case it would be really hard to manufacture the core because fins would need to be properly trimmed in the tanks area

In any CFD if you calculate porous media for car radiators you follow what CAEdevice explained. I had a quick look on porous media definition in MVRC cases, and it looks like that in directions other than normal, there's "0", shouldn't it be negative value to give "infinite resistance" in these directions? I had some doubts already with few of my simulations about air passing through HX.

Regarding fins behind HX - that's of course connected with back pressure, when radiator is more straight then you can see more of it's area from the back (if your outlet is big enough); with high angled ones air which went through HX "meets" the wall (upper part of sidepod or floor), and that raises locally the pressure, reducing performance of flow through. That's why fins behind radiator are there: to direct immediately the flow to the exit.
I must admit that I've chose other-way-around HX setting, and I guess I will keep it for this season (unless I won't find any elephant to sit on my RW, so I would need to redefine side/rear of the car). So because of such setting air from my radiators basically got stuck just above the floor, add to it small outlet like in Spa-spec and power loss disaster guaranteed (so let's guess what was my solution to get missing power % before Japan :twisted: )

If it comes to tight channel on the edge of the radiator - I'm still trying to fully understand that design, as it's seen on many other racecars... actually radiators were never my favorite parts in terms of racecars aero, so I need to catch up with some points here and there.

For small F1 radiator outlets I can only tell that these teams use high efficient radiator technology (double pass/microtubes) with properly calculated cooling circuits. I think you can get a feeling seeing this Ferrari (Manor) microtube intercooler:
https://www.youtube.com/watch?v=LS47125tUzk
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