Khamsin Virtual Racecar challenge 2013 (CFD model racing)

[CottrellGP]

What I find most interesting is that mine and Dan's cars...........were trumped by someone starting with a blank slate and creating something that looked very basic in comparison.

I in no way pretend to know much about aerodynamics, but my take on this is that unless you really know what the air flow is like over all the little air conditioners/deflectors/etc then there is a real chance that those parts are just messing up the airflow, not helping it... By keeping things simple its easier to make things right.....

May i ask why your using my 2011 car as a bad example please?

[astracrazy]

you don't need to post it twice, we saw it the first time

his not using it as a bad example, his using it as an example for what his on about. If you know what your cars doing then it doesn't apply to you.

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I'm planning on releasing my car early Feb time.

Hopefully we will have 1 pre-season test (like this one but fully legal etc) as well so we can all get some ground before the start of the season. Tidy up some illegals etc. I did mention it early on and it was commented on but i'm not sure if its been looked at. Would be pretty good if there is. Perhaps Nick can comment.

[wigglez28]

So cd.a is the drag created and Ci.a is downforce created. So that means my car is much more monza spec than Monaco?

[astracrazy]

So from the data does it mean I have a very good top speed but low grip?

So cd.a is the drag created and Ci.a is downforce created. So that means my car is much more monza spec than Monaco?

you had the lowest drag, but 2nd lowest downforce. You could of added a lot more wing angle for example to bump up your df level. Monaco is about the df remember

cd is drag, cl is lift. usually you would get a negative number i guess for downforce but there using positive. Yes the data you got would suit Monza more

[wigglez28]

Ok thanks I did use a big wing angle though. :L

[astracrazy]

Ok thanks I did use a big wing angle though. :L

well that was just a quick example. Perhaps your wings in general aren't giving good downforce. Are you using aerofoil shapes? Search it in google, you will get a lot of lift examples so flip it.

You need a good baseline of downforce from the car in general. Then change your wings to suit the track - thats obviously a simple approach.

Bottom line, if you had a steep angle on you wings i'd say its to do with the design of them. I dont get the low drag though if thats the case. I haven't seen your car so i can't really comment yet

[wigglez28]

Thanks for the help I used a longer (more emphasised curve On the bottom to increase speed underneath to create a low pressure zone and therefore downforce)

[Monster_Energy_F1]

Who's gonna be the first brave guy to show their car?

[N12ck]

Hello,

Julien and I are going to write a post mortem on the test and how we plan to tackle the issues we have faced with this so far when we get the time to do so.

If you think a car is illegal, it doesn't matter as that team will be informed soon and as I said we are allowing illegal cars for that race only as the bit we are interested in is making sure we have a system in place which works.

Overall I was impressed with how things went, however there are some issues needing addressed, for example:
Mesh Issues
Legality of cars
Turn around time

there are many more but you will see from our post mortem which we will put up soon along with CFD images and feedback.

As you all my appreciate Julien runs a CFD company and also holds down a full time job, I am working towards my MEng Degree and also doing separate CFD work, so I must apologise for the slow responses,

Thanks
Nick

[Monster_Energy_F1]

Sounds good to me. I understand you guys are busy, but I was wondering when I'll be able to join?

[N12ck]

when we have sent all PDF's + work out how to combat issues encountered, and finally updated the website, then we will move onto accepting the new teams (we have had 4-5 sign up since just before the challenge)

[Monster_Energy_F1]

Great. That'll only take a couple of weeks i guess?

[N12ck]

Great. That'll only take a couple of weeks i guess?

I intend on trying to get through all PDF's tonight if not, then they will all be sent by the end of tomorrow night,

The post mortem is a bit more difficult with Julien being based in Australia and me in the UK, so we will have a conversation soon about it,

Then Updating the website should take a few hours, possibly around 2 days, so I intend on getting to sorting the new teams by mid next week possibly mid week after, but to send the welcome packs to teams I need to amend the current welcome packs as we discovered issues so to adapt with this we need to add parts to be to the cars for future challenges,

so 1-2 weeks I would say as a rough guess

[machin]

May i ask why your using my 2011 car as a bad example please?

No offence intended mate; I actually meant it as a a good example of a really nice looking car with some interesting aero features which may cause issues to the air flow if they are not fully optimised using an iterative CFD process....

[machin]

I thought it would be interesting to work out the % of downforce front and rear, and the Cl.A values split into front and rear as well (its all derived from the same data, just presented slightly differently):-