Ground Effect Necessary???

[kalyangoparaju]

Guys i know how imp ground effect plays a role in F1. But i need one suggestion, i am trying to design the front wing of a car which has wings, while doing so do u think i need to take these ground effect into consideration, taking into account that the design speed of the vehicle is 100 kmph???

Plss do reply...

[gcdugas]

If the car moves fast enough to benefit from any wing or aero then it will also benefit from ground effects. With ground effects comes a host of stability issues..... ride height management, longitudinal porpoising caused by nose dive under braking and nose lift under acceleration, dealing with bumps etc. Its not easy, there are just more variables to be managed but ground effects yield downforce that costs very little in the way of drag.

[kalyangoparaju]

Hey thanks for the reply man.. Well tht that case u mean that i have to take the wing insuch a way tht it produces max downforce with as less drag as possible right???

[Jersey Tom]

Ground effects are generally associated with the underbody of the car rather than the front wing.

Is the *top* speed 100kph, or is the mid corner speed 100kph? Sounds like a Formula SAE / Formula Student car.

If it were me, I'd design and manufacture and TEST a good underbody first, before worrying about front and rear wings.

[kalyangoparaju]

Well its not a formula student car...but i am doing it as a project for my 4 yr bachelors. 100 kmph was the speed which i took in calculating the drag and lift for a particular wing type with different airfoil profiles.....Mostly it might be 3 quarters of the max speed....

How do u suggest me to go about the underbody???

[timbo]

way tht it produces max downforce with as less drag as possible right???

That's a tricky part. If you look at F1 wings (especially rear wing) you immediately notice that they are at so high AoA that they are definetely far from lift/drag optimum. I guess it is more likely "wing produces needed amount of downforce with as little drag as possible". However, F1 car has HUGE amount of power and it comes to transferring all of that power to the wheels, so if you have much less power han in F1 your goals would be different.
In case of ground effect, I guess it is not managable to create much downforce from flat bottom design with diffusor without ride hight of 2-5 cm and rock solid suspension. However flat bottom and diffusor will reduce LIFT abd drag underbody normally generates.
If you really want downforce from the underbody, you'd better setup skirts + bernully tube if regulation permits. That would be fun, as it generates SO MUCH downforce you won't need wings at all... Tricky to find optimal aerobalace, however

[Jersey Tom]

Well its not a formula student car...but i am doing it as a project for my 4 yr bachelors. 100 kmph was the speed which i took in calculating the drag and lift for a particular wing type with different airfoil profiles.....Mostly it might be 3 quarters of the max speed....

How do u suggest me to go about the underbody???

Taking classes in aerodynamics and CFD would be a good start.

[kalyangoparaju]

Taking classes in aerodynamics and CFD would be a good start.

I am doing 3 yr in aeronautical engineering and i am a student of aerodynamics...haha anyways TIMBO thanks for the suggestion but so what do u say i do with the bottom of my car, just leave it like that...flat bottom????may be even without a diffuser????

I way i am designing it is, i am trying to maximize the work of the wings in the production of the downfroce and reduced speeds, considering that at these speeds the ground effect or even the underbody doesnt cause change.

And could some one tell me how many kgs of download might act on the front wing of an f1 car????

[Jersey Tom]

You will likely get more downforce out of a good underbody than front and rear wings. Flat is an option, but a diffuser at the rear would be a good idea. Why wouldn't you?

If you do some good suspension work, maybe higher front ride freq or rate than rear, or keeping the pitch axis near the front axle under braking, you can get the underbody to increase its AoA significantly under the brakes without bottoming out the front of the chassis.

If you want a high DF, low speed package I'd say go with that and you can work on a multi-element (3? for such low speed) high-AoA front wing, maybe 2 rear.

Your whole aero package design is going to have to be linked in with the suspension kinematics, weight distribution, and tires in order to work right.

[timbo]

TIMBO thanks for the suggestion but so what do u say i do with the bottom of my car, just leave it like that...flat bottom????may be even without a diffuser????

Well, having clean underfloor airflow wold help anyway. You'd have less drag/lift. Now, if you want to get significant downforce from flat bottom setup with diffusor you gotta keep your ride-hight low and have very stiff suspension, that would bad for grip/driveability. I think skirts is a way to go, all in all it is the most effective solution, that's why it was outlawed so fast in F1.

And could some one tell me how many kgs of download might act on the front wing of an f1 car????

I heard figures of around 700-800 kgs.

[alexbarwell]

For the speed, I would have thought reducing aero-drag was as important as downforce since both increase exponentially with speed - if you have trouble getting quickly up to speed anyway.

[gavindegraw1]

how to make it speedy, is there any solution ?

[rough_wood]

Taking classes in aerodynamics and CFD would be a good start.

I am doing 3 yr in aeronautical engineering and i am a student of aerodynamics...haha anyways TIMBO thanks for the suggestion but so what do u say i do with the bottom of my car, just leave it like that...flat bottom????may be even without a diffuser????

I way i am designing it is, i am trying to maximize the work of the wings in the production of the downfroce and reduced speeds, considering that at these speeds the ground effect or even the underbody doesnt cause change.

And could some one tell me how many kgs of download might act on the front wing of an f1 car????

Making a flat underbody will simplify the solution, but you should also definately have a simple diffuser.