☰ MENU

Second Chance Garage

For the Classic Car Restoration Enthusiast

Second Chance Garage


Second Chance Garage

For the Classic Car Restoration Enthusiast

Second Chance Garage

Second Chance Garage

For the Classic Car Restoration Enthusiast

Second Chance Garage

FEATURE ARTICLES

"Seeing is Believing" says fluid dynamics expert

By John Gunnell

David Woodruff makes Cranberry dryers work better and racing cars go faster. He once gained a heap of horsepower for a Bonneville Salt Flats racing car by re-designing its hood scoop. Woodruff is best known in the racing ranks as Woody and his company is called Aero by Woody (www.designdreams.biz).

"I do primarily what's called CFD," Woody told Second Chance Garage during the Performance Racing Industry (PRI) Show in Indianapolis. "That stands for Computational Fluid Dynamics. If you have a car you plan to put in a wind tunnel, I can put it in a digital wind tunnel and save you lots of work and money."

David Woodruff is better known as 'Woody' to people in the hot rooding and racing worlds.

David Woodruff is better known as "Woody" to people in the hot rooding and racing worlds.


A racer can have his car digitally scanned. Then, Woody can put the digital model of the car in his digital wind tunnel, analyze it and tell him or her what not to take to a real world wind tunnel. "We find the bad ideas first with a computer," he said. "That's much cheaper than finding it out at the wind tunnel."

Woody can analyze anything that has to do with fluid flow whether it's air or liquid or whatever. Coolant flow through a cylinder head or airflow through a hood scoop can be mapped on the computer. "It doesn't matter if it's inside air or outside air or something commercial like a cranberry dryer," said Woody. "We can make all of these things work better by managing the fluid or air flows. It's about raising the efficiency of whatever device or devices you're trying to use. And if you have several devices (as in a multiple carburetion setup), we figure out how to get them to work together the way you want them to."

This hood scoop on a Bonneville racing car didn't look pretty, but it upped horsepower after Woody improved the air flow through it.

This hood scoop on a Bonneville racing car didn't look pretty, but it upped horsepower after Woody improved the air flow through it.


Using computer aided design (CAD) files and programs, Woody was able to illustrate the air flow patterns in this intake manifold.

Using computer aided design (CAD) files and programs, Woody was able to illustrate the air flow patterns in this intake manifold.


After a car or other item is scanned, a computerized scan file is produced. This has to be converted into a CAD file that can be put into a CAD program. Woody uses a CAD file called Solidworks, but there are other ones that can also be used. "As long as it's a CAD file, I can usually import it," Woody explained. "I may have to fix it up a bit. And, in the case of some specialty vehicles, we just take pictures and measurements of the vehicle and make a rough model just to get a base line. We're going to change it anyway, so we just need an idea of where the design is good and where it's bad."

Once the base line is established, Design Dreams can start massaging the changes. These are then incorporated into the real car's final design in two or three variations. The car is then taken to the real wind tunnel to see if progress has been made. "The question is whether we are going to get the wind flow results we expect," noted Woody. "The results can tell us if the design is good."