[KVRC] Khamsin Virtual Racecar Challenge 2016

Post here information about your own engineering projects, including but not limited to building your own car or designing a virtual car through CAD.
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CAEdevice
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Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2016

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LVDH wrote:Yes and no. For the high down force my DoEs and optimizations from last year showed that just maximizing downforce more or less puts the CoP into right right position.
For the efficiency races it will be more difficult.
But then again yes, getting the last cm right is very difficult.
It also depends on the car configuration. With my "covered wheels" F1 shape, I have a balanced car in high efficiency setup and a (relative) lack of front downforce in extreme downforce races (see preseason race results)

At the moment I'm having great improvement where I did not need it (cooling).

I wonder how did Variante could get all that downforce!

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RicME85
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Joined: 09 Feb 2012, 13:11
Location: Derby

Re: Khamsin Virtual Racecar Challenge 2016

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I ran another couple of tests last night with some tweaks to the rear wing to try and balance the car out. I have gone from a downforce distribution of 38:62 to 41:59 but in doing so go 0.04 seconds slower around Monaco.

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CAEdevice
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Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

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RicME85 wrote:I ran another couple of tests last night with some tweaks to the rear wing to try and balance the car out. I have gone from a downforce distribution of 38:62 to 41:59 but in doing so go 0.04 seconds slower around Monaco.
What about Nurburgring?
Is the total df the same?

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RicME85
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Joined: 09 Feb 2012, 13:11
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Re: Khamsin Virtual Racecar Challenge 2016

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The 'ring is 0.09 slower.
Total downforce is down by around 500N which has come from the rear wing having its profile scaled down and also the wing being dropped like a Le Mans spec rear wing.
Went from:
Drag area - Cd.A: 1.22 m2
Downforce area - Cl.A: -4.36 m2

To:
Drag area - Cd.A: 1.09 m2
Downforce area - Cl.A: -3.83 m2

I get that its going to happen due to the loss of downforce, it is just frustrating when trying to balance the car.
I think I might have to return the original rear wing and see what a change of AoA on the front wing will do. Thankfully I have a wiggle room with the engine as I have a difference of around 50.

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RicME85
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Joined: 09 Feb 2012, 13:11
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Re: Khamsin Virtual Racecar Challenge 2016

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For those interested about AWS.
I have done 5 simulations this month which comes to a figure of £11.56 or £2.31 a run.

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machin
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Joined: 25 Nov 2008, 14:45

Re: Khamsin Virtual Racecar Challenge 2016

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For Nurburgring and Monaco the balance is less important because there is little penalty for excess drag... even though you only changed the rear wing you still lost some front downforce: In the first configuration you went from a Cl.A front = 1.66.... In the second configuration your Cl.A front fell to 1.57, which explains why you're slower despite lower drag... Unfortunately flow changes downstream sometimes affect flow upstream, which makes it difficult to set the balance... (Hence F1 drivers always complaining that they couldn't get the balance right, despite having a whole team helping them to get it right!).
COMPETITION CAR ENGINEERING -Home of VIRTUAL STOPWATCH

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LVDH
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Joined: 31 Mar 2015, 14:23

Re: Khamsin Virtual Racecar Challenge 2016

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machin wrote:Unfortunately flow changes downstream sometimes affect flow upstream, which makes it difficult to set the balance... (Hence F1 drivers always complaining that they couldn't get the balance right, despite having a whole team helping them to get it right!).
At least we are dealing with constant pitch and ride height (somehow still difficult, though).

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CAEdevice
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Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2016

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I have almost completed my car update for the first race (only a couple of legality issues). I fear it will not be balanced (same cop as the pre season race). I think Variante, JJR and Mantium will be still faster. I may battle with TF.

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LVDH
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Joined: 31 Mar 2015, 14:23

Re: Khamsin Virtual Racecar Challenge 2016

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Same CoP? I do not understand. I mean getting it right is not that easy. But slightly changing the rear wing and testing two or three configurations will get it balanced. Yes at the cost of downforce. But wasn't your car so far off that it would pay off to loose some downforce and still get a better lap time? Do you use the virtual lap time simulator?

cdsavage
cdsavage
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Joined: 25 Apr 2010, 13:28

Re: Khamsin Virtual Racecar Challenge 2016

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A quick reminder for everyone: the round 1 submission deadline is a week from now (Apr 28).

I have updated the rulebook with some very minor adjustments, these will only apply for round 2 onwards (not for the upcoming round). The only significant change is that in K3.1 (nose), there was some ambiguity on the "structurally realistic" requirement, so there's a new requirement stating that as the plane is moved rearwards towards the cockpit, the load-bearing regions must remain at least 75mm high/wide. This really only applies to models using an "s-duct". Also the requirement for the cooling differential for K4.1 option 2 is now 17 Pa.m^2 rather than 17.5 - the original 17.5 figure was a mistake, but it didn't affect any of the entries from round 0 anyway.

For anyone planning on submitting an entry for the introductory subclass: I've updated the guide files on the KVRC site. There are some small changes to the standard parts, and there's slightly more room in the region ahead of the front suspension. Any parts modeled to the original parts should fit the new parts without problems, but if there's any doubt, for the next round we'll continue to use the original parts and only switch over for round 2.

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RicME85
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Joined: 09 Feb 2012, 13:11
Location: Derby

Re: Khamsin Virtual Racecar Challenge 2016

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Whoa thats an ugly change to the intake on the intro car

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CAEdevice
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Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

Re: Khamsin Virtual Racecar Challenge 2016

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LVDH wrote:Same CoP? I do not understand. I mean getting it right is not that easy. But slightly changing the rear wing and testing two or three configurations will get it balanced. Yes at the cost of downforce. But wasn't your car so far off that it would pay off to loose some downforce and still get a better lap time? Do you use the virtual lap time simulator?
Yes, I could easily obtain 1.65m, but I would have to reduce the rear wing contribution. What I was trying, is to increase the front wing downforce... that seems very difficult!

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LVDH
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Joined: 31 Mar 2015, 14:23

Re: Khamsin Virtual Racecar Challenge 2016

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All you need the the old JJR front wing. It is so far the best thing I have seen.

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CAEdevice
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Joined: 09 Jan 2014, 15:33
Location: Erba, Italy

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LVDH wrote:All you need the the old JJR front wing. It is so far the best thing I have seen.
Maybe you are right, but there is not enough time before the next race (I'm going in the opposite direction at the moment).

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AratzH
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Joined: 07 May 2013, 09:24
Location: Michigan

Re: Khamsin Virtual Racecar Challenge 2016

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Definitively front downforce is the biggest challenge, specially with a "no front wing" configuration. For next round I have been forced to implement a front winged version in order to balance the car and gain some global downforce. Still too far from Variante.

It is interesting to note that in the last Silverstone 6hr all three LMP1 top teams got very similar best lap times, within 0.5s, with very different concepts, Audi and Toyota use a front wing and Porsche a diffuser.

Regarding the cooling option 2, I understand that we are going to use the porosity method for next round. Is it possible to have the properties of the porous medium? Ideally the porosity and flow vs pressure drop characteristics.
MVRC -> TF