Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Using shark scales to design better drones, planes, and wind turbines

07.02.2018

Bioinspired vortex generators increase airfoil lift, decrease drag

To build more aerodynamic machines, researchers are drawing inspiration from an unlikely source: the ocean.


A team of evolutionary biologists and engineers at Harvard, have demonstrated a new, structure inspired by shark skin that could improve the aerodynamic performance of planes, wind turbines, drones and cars.

Image courtesy of James Weaver/Havard University

A team of evolutionary biologists and engineers at Harvard University, in collaboration with colleagues from the University of South Carolina, have shed light on a decades-old mystery about sharkskin and, in the process, demonstrated a new, bioinspired structure that could improve the aerodynamic performance of planes, wind turbines, drones and cars.

The research is published in the Journal of the Royal Society Interface.

Sharks and airplanes aren't actually all that different. Both are designed to efficiently move through fluid (water and air), using the shape of their bodies to generate lift and decrease drag. The difference is, sharks have about a 400 million-year head start on the design process.

"The skin of sharks is covered by thousands and thousands of small scales, or denticles, which vary in shape and size around the body," said George Lauder, the Henry Bryant Bigelow Professor of Ichthyology and Professor of Biology in the Department of Organismic and Evolutionary Biology, and co-author of the research. "We know a lot about the structure of these denticles -- which are very similar to human teeth -- but the function has been debated."

Most research has focused on the drag reducing properties of denticles but Lauder and his team wondered if there was more to the story.

"We asked, what if instead of mainly reducing drag, these particular shapes were actually better suited for increasing lift," said Mehdi Saadat, a postdoctoral fellow at Harvard and co-first author of the study. Saadat holds a joint appointment in Mechanical Engineering at the University of South Carolina.

To help test that hypothesis, the researchers collaborated with a team of engineers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS). For inspiration, they turned to the shortfin mako, the fastest shark in the world. The mako's denticles have three raised ridges, like a trident. Using micro-CT scanning, the team imaged and modeled the denticles in three dimensions. Next, they 3-D printed the shapes on the surface of a wing with a curved aerodynamic cross-section, known as an airfoil.

"Airfoils are a primary component of all aerial devices," said August Domel, a Ph.D. student at Harvard and co-first author of the paper. "We wanted to test these structures on airfoils as a way of measuring their effect on lift and drag for applications in the design of various aerial devices such as drones, airplanes, and wind turbines."

The researchers tested 20 different configurations of denticle sizes, rows and row positions on airfoils inside a water flow tank. They found that in addition to reducing drag, the denticle-shaped structures significantly increased lift, acting as high-powered, low-profile vortex generators.

Even if you don't know what a vortex generator is, you've seen one in action. Cars and planes are equipped with these small, passive devices designed to alter the air flow over the surface of a moving object to make it more aerodynamic. Most vortex generators in the field today have a simple, blade-like design.

"These shark-inspired vortex generators achieve lift-to-drag ratio improvements of up to 323 percent compared to an airfoil without vortex generators," said Domel. "With these proof of concept designs, we've demonstrated that these bioinspired vortex generators have the potential to outperform traditional designs."

"You can imagine these vortex generators being used on wind turbines or drones to increase the efficiency of the blades," said Katia Bertoldi, William and Ami Kuan Danoff Professor of Applied Mechanics at SEAS and co-author of the study. "The results open new avenues for improved, bioinspired aerodynamic designs."

"This research not only outlines a novel shape for vortex generators but also provides insight into the role of complex and potentially multifunctional shark denticles," said Lauder.

###

The Harvard Office of Technology Development has protected the intellectual property relating to this project and is exploring commercialization opportunities.

The research was co-authored by James Weaver of the Wyss Institute for Biologically Inspired Engineering at Harvard, and Hossein Haj-Hariri, Dean of Engineering and Computing at the University of South Carolina. This research was supported by Office of Naval Research and the National Science Foundation.

Media Contact

Leah Burrows
lburrows@seas.harvard.edu
617-496-1351

 @hseas

http://www.seas.harvard.edu/ 

Leah Burrows | EurekAlert!

More articles from Power and Electrical Engineering:

nachricht Scientists print sensors on gummi candy: creating microelectrode arrays on soft materials
21.06.2018 | Technische Universität München

nachricht Electron sandwich doubles thermoelectric performance
20.06.2018 | Hokkaido University

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View

22.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>