Challenge for CAD and CFD guys

Here are our CFD links and discussions about aerodynamics, suspension, driver safety and tyres. Please stick to F1 on this forum.
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jjn9128
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Joined: 02 May 2017, 23:53

Challenge for CAD and CFD guys

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It's off season and I'm maybe going a little stir crazy but bear with me :lol:

Background
This past week or so motorsport claimed the Mercedes W11 pulled 3000kg of downforce at 276km/hr through copse corner - this translates to a CzS of 8.175 which seems ridiculously high, however, from a Kyle Engineers video (CFD guy on youtube who recently left Mercedes) you can work back to a similar number over 8. Back in the late 80s-early 90s F1 cars only produced around half that (3.6<CzS<4.5 from Agathangelou & Gascoyne), the peak being in 1992/3 with the full active cars.

Now this got me to thinking, what if F1 had never gone through all the meddling rule changes between 1994 and now which forces the car shape into ever more restrictive boxes (below is the entire bodywork regulation for '88!!). What would they look like? Would similar concepts be optimal? Would different concepts produce similar performance? Would the level of performance plateau around a similar value to 2020? Could they be even more efficient because there was so much freedom so draggy little elements were not necessary?

The Challenge
So the challenge is to join me in CAD'ing up a car (and maybe do some CFD) to the rules of the 1990s but with modern aero knowledge and CAD techniques. I only have access to 1988 and 1994 rule books so am using the 1988 rules as a baseline because there weren't many changes between then and 1993 (last year of the 2.15m cars). I am postulating that safety would have kept up with the times though, so the halo, modern cockpit (length, headrest, seatback and entry template), rear impact structure and standard side impact spars are included, I'm undecided on the plank because while ubiquitous to all FIA series it was the precursor to the floor step which I want to avoid.

Cars would be 2.15m wide with a 1.4m chassis, flat bottom, with a 3.5litre engine (your choice V8-12 but I'm going V10). I'm guessing KERS would have made it to F1 by now as McLaren/Mercedes were working on it in 1998 -- so we're talking 1100-1200bhp, 575kg (including driver) monsters!!!


Thoughts? Opinions? Any takers?

ARTICLE 3 – COACHWORK AND DIMENSIONS
1) The overall width of the car including complete wheels shall not exceed 215cm with the steered wheels in the straight ahead position.

2) The coachwork ahead of the front wheels may be extended to an overall maximum width of 150cm. Nevertheless, any part of the coachwork ahead of the front wheels exceeding an overall width of 110cm shall not extend above the height of the front wheel rims with the driver aboard seated normally and irrespective of the fuel load.

3) The overall maximum width of the coachwork behind the rearmost edge of the complete front wheels and front of the centreline of the rear wheels shall not exceed 140cm. The crushable structure is included in this width. Between the rear edge of the complete front wheels and the front edge of the complete rear wheel all sprung parts of the car visible from directly beneath the car must lie on one plane within a tolerance of +/- 5mm.

All these parts must produce a uniform, solid, hard, rigid (no degree of freedom in relation to the body/chassis unit) impervious surface, under all circumstances

The periphery of the surface formed by these parts may be curved upwards with a maximum radius of 5cm

No parts of the bodywork in front of the centreline of the rear wheels and extending above the height of the rear complete wheels may project beyond 50cms each side of the longitudinal axis of the car.

4) Coachwork behind the centreline of the rear wheels shall not exceed 100cm in width

5) Except in the case of front wheel drive when the measurement will be taken from the centreline of the rearmost substantial load carrying wheels no part of the car shall be more than 60cm behind the centreline of the rear most driving wheels. No part of the car shall be more than 120cm in front of the centreline of the foremost fronts wheels. The centreline of any wheel shall be deemed to be half way between two straight edges perpendicular to the surface on which the car is standing, placed against the opposite side of the complete wheel at the centre of the tyre tread.

6) Height: Except for the safety roll-over structures no part of the car shall be higher than 100cm from the ground with the car in normal racing trim with the driver aboard seated normally Any part of the safety roll-over structure higher than 100cm from the ground must no be shaped to have a significant aerodynamic influence on the performance of the car

7) Any specific part of the car influencing it's aerodynamic performance
- must comply with the rules relating to coachwork
- must be rigidly secured to the entirely sprung part of the car

Any device or construction that is designed to bridge the gap between the sprung part of the car and the ground is prohibited under all circumstances

No part having aerodynamic influence and no part of the coachwork may under any circumstances be located below the geometrical plane generated by the plane surface provided for article 3.5


ARTICLE 10 – BRAKES
2) Air ducts for the purpose of of cooling the front brakes shall not protrude beyond:
- a plane parallel to the ground situated at a distance of 140mm above the horizontal centreline of the wheel
- a plane parallel to the ground situated at a distance of 140mm below the horizontal centreline of the wheel
- a vertical plane parallel to the inner face of the front rim and displaced from it by 120mm toward the centreline of the car
Furthermore such ducts, when viewed from the side must not protrude beyond the periphery of the tyre in a forward sense or the rim in a rearward sense.


ARTICLE 13 – SAFETY
f: Survival cell
6) The internal cross sectional area of the cockpit from the soles of the drivers feet to behind his seat shall nowhere be less than 700cm2 and the minimum width must be 25cm over the whole length of the cockpit.
#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

6 of 12
6 of 12
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Joined: 11 Jan 2014, 16:02

Re: Challenge for CAD and CFD guys

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Well, how can I say this... I have no capability in that area at all, but I'd love to see the results 🙈
No, Kimi, no. You will not have the drink.

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Vyssion
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Re: Challenge for CAD and CFD guys

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Why do I feel like I have already been volunteered to do the CFD for this? 🤔🤔🤔🤔🤔

Can't quite put my finger on why that might be.... jjn....................
"And here you will stay, Gandalf the Grey, and rest from journeys. For I am Saruman the Wise, Saruman the Ring-maker, Saruman of Many Colours!"

#aerosaruman

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jjn9128
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Joined: 02 May 2017, 23:53

Re: Challenge for CAD and CFD guys

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Vyssion wrote:
01 Feb 2021, 02:49
Why do I feel like I have already been volunteered to do the CFD for this? 🤔🤔🤔🤔🤔

Can't quite put my finger on why that might be.... jjn....................
You already have a backlog of CFD to get on with :P

I can use openFoam :wink:
#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

WillGuna
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Joined: 04 Mar 2019, 17:01

Re: Challenge for CAD and CFD guys

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An interesting question would be the tire/wheel configuration. What would be the ideal solution in terms of width and diameter if it was completely unrestricted? Would they go for narrower front tires for better aero efficiency?

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Stu
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Location: Norfolk, UK

Re: Challenge for CAD and CFD guys

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WillGuna wrote:
01 Feb 2021, 18:54
An interesting question would be the tire/wheel configuration. What would be the ideal solution in terms of width and diameter if it was completely unrestricted? Would they go for narrower front tires for better aero efficiency?
In real life, Tyrell once ran with front tyres on both axles at Hockenheim (the old circuit), they got stopped by the FIA (or Bernie, can’t recall which). They were also planning to run rear tyres on both axles for Hungary.
Today’s cars are comparatively over-tyred on the front and under-tyred on the rear compare with that era (2150 wide cars of late 80’s/early 90’s.
Perspective - Understanding that sometimes the truths we cling to depend greatly on our own point of view.

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jjn9128
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Joined: 02 May 2017, 23:53

Re: Challenge for CAD and CFD guys

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WillGuna wrote:
01 Feb 2021, 18:54
An interesting question would be the tire/wheel configuration. What would be the ideal solution in terms of width and diameter if it was completely unrestricted? Would they go for narrower front tires for better aero efficiency?
I've often said the tyres are too big, Gordon Murray thought they should be narrower when he presented a concept for F1 and I tend to agree, not just aerodynamics but overall grip too. It might be an interesting study, but for another time.

Stu wrote:
01 Feb 2021, 19:01
Today’s cars are comparatively over-tyred on the front and under-tyred on the rear compare with that era (2150 wide cars of late 80’s/early 90’s.
True, but not by much. The rear tread was 1.5x the front back then, whereas now it's 1.33x. It's going back to 1.5x in 2022. The treads are also a bit bigger - 10" & 15" (254mm & 381mm) vs 305mm & 405mm. Current tyres are too large IMO.

This is all off topic 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