RedNeck wind tunnel test

This is what the air flow is doing in thi9s picture.
Attachment 49612

Hi Bob, say just for fun can you reverse the direction of your fans? I know they won't be efficient spinning in reverse but if the pressure is on the back of the car at speed that must be a higher pressure area, and quite possibly the fast moving air under the car would be a lower pressure area, and the heat is dumped underneath. Food for thought...

Quote:

---

Originally Posted by 904svo

This is what the air flow is doing in thi9s picture.
Attachment 49612

---

Yeah precisely, with a diffuser placed as far back as possible at the bottom of the car should prevent that from happening cuz the pink flow on the pic will either come back up further back or will not as much cuz the diffuser will keep the airflow as straight as possible and not kinking upwards. Am I correct?

https://www.youtube.com/watch?v=Z6MA0Tc90io


Bernoulli says this about the diffuser:

Quote:

---

It uses Bernoulli's principle, such that the pressure decreases while the velocity increases. Since the pressure below the car is lower than on the side and above the car, downforce is produced if implemented correctly.

---

If you don't use the diffuser, you increase pressure under the body which then may or may not equal the pressure in the middle and above the body.

I also try reversing the fans and it had the same effect. The fans were pulling in the hot air from the engine. (I think) which was coming from the bottom of the car
(Bernoulli effect) as soon as it get warmer here I'm going to add a diffuser to move the air flow further back so the air flow from the top of the body will supply cooler air to the radiator. Wish me luck.

Quote:

---

Originally Posted by 904svo

Wish me luck.

---

I am!!

Quote:

---

Originally Posted by 904svo

This is what the air flow is doing in thi9s picture.
Attachment 49612

---

I think the air is doing this.
http://thefactoryfiveforum.com/attac...6&d=1452567811

Also the air from under the car is full of road dirt. The back of the car gets dirty quickly.

In the cockpit we get no wind up to 80 mph. Have not tried much faster yet.
Bob

Check out this web site, don't forget that the bottom of your engine is open and any hot air will be included in this air flow.

http://www.racecar-engineering.com/t...-aerodynamics/