Research after World War II revealed something that came to be known as the “Gray’s paradox.” It was found that dolphins swimming through the water go faster and farther than could be explained considering how much food was consumed
After study it was determined that the flexible skin of dolphins did something to their flow through the water. The skin kept the flow laminar, which is the opposite of turbulent, and laminar flow has lower skin friction.
For the next 50 years, researchers tried to mimic the skin of dolphins to reduce the drag on ships and airplanes. No practical devices came out of the research. But now a former University of Mississippi mechanical engineering professor, Dr. Sumon K. Sinha, has developed a device, the Flexible Composite Surface Deturbulator (FCSD) tape, that effectively reduces drag from air flow over surfaces. Reducing drag and turbulence can have a significant impact increasing fuel efficiency.
In aircraft test flights, Sinha’s deturbulator has produced 18% better performance. He’s also seen good results with tests on his minivan and on trucks. While he has used sailplanes and light aircrafts to test the deturbulator, his first major market for the device is for semi tractor-trailer trucks.
Sinha says he believes with the high prices of diesel, and these trucks averaging only six miles per gallon, this should be an excellent market for the deturbulator.
‘Trucking market is huge’
“The trucking market is huge,” Sinha said. “Right now, we are looking at reducing the aerodynamic drag of trucks because diesel prices have gone up tremendously affecting the prices of everything transported by diesel trucks such as groceries and clothes. Trucks get such low miles per gallon that even by increasing mileage .1 mpg, you end up saving more than $1,200 per year for trucks. We can increase the mileage of a truck from .25 to .28 mpg with a minimum application of the turbulator by putting two sheets on the cab. That is just the beginning. We have put more on the sides of the trailer and have been able to increase the mileage even more so to about close eight percent in some cases.”
The deturbulator tape is a flexible skin, which can respond to fluctuations in the air flow. As a result, it minimizes turbulence. If you are following a truck on the highway, and get shaken, that is turbulence coming off the truck that is responsible for a lot of the drag that reduces fuel efficiency.
Creating a virtual tail
What the deturbulator does is streamlines the truck. Sinha calls it a “virtual tail.” If a cone-shaped tail were added to make the truck look more streamlined like a missile, that would decrease turbulence and increase fuel efficiency. But a physical tail is too dangerous and would make it difficult to pull up to loading ramps.
“Using a virtual air tail is what my device does,” says Sinha, whose invention was recently featured in an article in November 2007 edition of Defense Technology International. “We use the same concept on aircraft wings. On aircraft wings it is skin friction, air rubbing on the wings, that creates most of the drag. The deturbulator intentionally makes the air flow separate and pulls turbulence away from the separated area so you can get increased lift and lower drag.”
Sinha had successful flight tests in December 2006 with Dick Johnson, a well- known test pilot for sailplanes since 1960. The test showed the deturbulator reduced skin friction and turbulent energy, yielding less drag and more lift. After the test, Johnson said the new Sinha deturbulator could be the first really significant drag-reducing aerodynamic invention since the development of the now-common laminar-flow airfoils that were developed some 65 years ago.
“Sailplanes by their very nature are extremely efficient,” Sinha said. “Using a deturbulator can make them even more efficient. That is why that demonstration was so important. We could get almost 20% greater performance. That put this technology on the map.
“This new technology may be used to improve the efficiency of virtually any kind of body that moves through the air, most notably aircraft and motor vehicles. Tests on a passenger van that was only partially deturbulated have yielded 10%-15% better gas mileage, corresponding to $300-$500 in annual fuel savings, assuming $3.00/gallon and 15,000 miles per year average driving.”
Sinha said the reason he tested the device on a sailplane is that they represent the pinnacle of aerodynamic efficiency. A lot of new technology shows up first on sailplanes, like composite materials.
There are many other possible uses of this technology like making large wind turbines more efficient.
“Those represent a clean way of making electric power,” he said. “Using our devices we can perhaps make it even cheaper to produce electricity using wind instead of coal.”
Commercial aircraft is another possibility. All airlines are working with small margins because of fuel prices. Sinha said his deturbulator could be used to retrofit existing airlines. But in order to operate in that environment, he needs to do a lot more research and development because of the extreme conditions airplanes operate under with a combination of high altitude, high speed, wind, sleet and snow.
As fuel costs continue to increase, uses of devices like the turbulator would be expected to become increasingly popular. Sinha said one advantage of the device is that it works no matter what the fuel source is: diesel, biodiesel, gasoline, electric or hydrogen.
“It increases efficiency no matter what the fuel happens to be,” said Sinha, who was a professor at Ole Miss for 17.5 years before launching his deturbulator business.
The technology is based on existing and pending U.S. and international patents by Sinha. Research into developing the technology has been supported by grants from NASA, the National Science Foundation and the Department of Defense.
For more information, visit www.sinhatech.com or call (662) 801-6248.
Contact MBJ contributing writer Becky Gillette at firstname.lastname@example.org.