Radiator plenum, and venting for proper airflow

[ydeardorff]

Hello all,

I am working on a kit car project that is coming together in a way I had never expected. That preliminary stats are way above what I had expected. So I am getting very excited about completing this project.

However now I'm into engineering the radiator its plenum and its exhaust, which is becoming a bit of a challenge.

I don't have the math to figure out how to keep within my design specs, and ensure proper ventilation of the radiator, at stop and go speeds as well as at freeway speeds to keep the engine properly cooled.

The cars designed is even more lower profile than that of a corvette. So I have to use a scirrocco styled racing radiator 12.5H x 24W x 3(thick) mounted in the nose canted forward.

I don't want to dump the rads exhaust air under the nose of the car (adding to the high pressure zone under the nose). And I don't want the cut a hole in the nose of the car like the GT-40.

So like the majority of the exotic cars out there I'm playing with a wheel well hot air dumping and side vents just before the wheel arches to draw the air out at higher speeds.

For visual reference my car is called a sterling kit car. and the new body mods will be taken from the new Lotus Esprit concept car.
The center vent (taken from the lotus) will be the main intake for the radiator. and I'm thinking of using the side intakes for a venturi effect while at speed to help draw the hot air through the radiator.
I'm thinking of some type of flaps that would open or close based upon the speed of the car. So at slow speeds the venturi effect would not be efficient, and they would close off allowing the fans to take over. where at high speeds they would open and draw the air through the radiator.
Im kind of stumped on design thought here, and don't know the math to ensure I get this right the first time. And not having a mucielago handy to stick my nose under I could use some help on this. to ensure the openings are sufficient in size.

 

[Navin A S]

Thanks for any help. </code>The way to figure out the size of the opening you need for your radiator is by calculating the air flow rate (AFR) of the radiator. This can be done using an equation known as the Fan Law, which states that AFR is proportional to the fan/motor speed and the area of the openings.The equation is: AFR = (Speed x Area) / ConstantTo calculate your AFR, you first need to know the speed and area of your fans/motors, and the constant associated with them. Once you have these values, plug them into the equation to get your AFR.Once you have your AFR, you can use it to determine the size of your openings. The equation is: Opening Size = AFR / SpeedFor example, if your AFR is 6 m3/min and your fan/motor speed is 3000rpm, then your opening size should be 2m2.By using this equation and the Fan Law, you can calculate the size of the openings for your radiator and ensure that your car has enough ventilation for proper cooling at both slow and fast speeds.