Computer Simulation Used to Investigate Mystery of Dolphin’s Speed

How do dolphins maintain a swimming speed of up to 10 meters per second? Standard engineering calculations predict that the dolphin’s muscles would have to be seven times more powerful than they actually are to achieve that speed. An alternative explanation is that the dolphin somehow reduces the frictional drag on its skin through the water to a much lower level than experienced by other bodies in water.
Investigating the Mystery of the Dolphin’s Speed Using COSMOSFloWorks™ and EFD.Lab Software

 

 

 

 

 

 

 

 

 

 

This might be possible if the dolphin were able to maintain laminar flow as opposed to turbulent flow which would be expected at the speeds at which it travels. Laminar flow generates much less drag and so could account for the dolphin’s extraordinary speed.

Research scientist V.V. Pavlov at the Crimean State Medical University in the Ukraine used COSMOSFloWorks™ computational fluid dynamics (CFD) software to investigate this question, which has been known for 70 years as “Gray’s Paradox” after Sir James Gray who first pointed it out. Pavlov simulated the detailed hydrodynamics of the flow around the dorsal fin of the harbour porpoise (see the paper “Dolphin skin as a natural anisotropic compliant wall,” published in Bioinspiration & Biomimetics). COSMOSFloWorks is a SolidWorks product developed by Flomerics and uses the same underlying technology as the EFD.Lab, EFD.Pro, and EFD.V5 software products from Flomerics.

Pavlov found that the shape of the dolphin’s skin matches the flow conditions around the dorsal fin. He concluded that the skin structure appears to allow the flow-skin interface to behave as an anisotropic compliant wall in the regions of favorable and adverse pressure gradients on the skin. Apparently, by complying with flow conditions, the skin has the effect of suppressing instability growth in the boundary layer and reducing turbulence. This information may aid in the design of compliant walls which might increase speed and reduce fuel consumption of ships and airplanes, among other applications.

“The elegance of natural solutions inspires new ideas in technology and engineering,” Pavlov said. “The drag-reducing adaptation that dolphins have perfected over 50 million years is worth investigating because of their potential for improving the performance of human transport. By studying the relationship of the flow around the dolphin’s fin to the structure of its skin we have gained insights that may prove very useful in designing compliant walls.

COSMOSFloworks played a crucial role in this analysis through its tight integration with SolidWorks 3D computer aided design (CAD) software,” Pavlov continued. “We were able to perform direct analysis on the geometric model that we created of the dolphin’s fin, maintaining all the intelligence in the 3D CAD model. The CFD software makes it easy to perform flow simulation because it automatically analyzes the geometry and generates the computational grid in the background while the user interacts with the familiar CAD interface.”

For more information about the EFD.Lab, EFD.Pro, and EFD.V5 software products from Flomerics, please go to http://www.nika.biz.


Rating:
Reviews:
Review Article
  • October 09, 2008
    Reviewed by 'ydhananjay'
    The article is interesting! However, some thhings are not clearly described.
    It is understood that, for Favourable Pressure Gradient which is positive Pressure Gradient towards downstream and Separation of flow does not occur hence no reversal of flow. The opposite is true in adverse Pressure Gradient. This can be achieved by changing the shape of the body, i.e. the dolphin's fin must be changing.
    There might be some more things other than this to the anisotropic compliant wall. That need to be described in detail for a common reader.
    Overall, the article is good and informative.
    Thanks and regards.

      Was this review helpful to you?   (Report this review as inappropriate)


For more discussions, follow this link …
Rand3D

Featured Video
Jobs
Mechanical Engineer I for Air Techniques, Inc at Melville, NY
Proposal Support Coordinator for Keystone Aerial Surveys at Philadelphia, PA
Upcoming Events
The Rise of Mechatronics at Dassault Systèmes San Diego 5005 Wateridge Vista Drive San Diego CA - Sep 12, 2017
The Rise of Mechatronics at Buca di Beppo - Pasadena 80 West Green Street Pasadena CA - Sep 13, 2017
The Rise of Mechatronics at Dassault Systèmes Santa Clara 3979 Freedom Circle, Ste 750 Santa Clara CA - Sep 14, 2017
The 30th Annual Integrated Process Excellence Symposium & Training at Wyndham Grand Bonnet Creek Resort Orlando FL - Sep 18 - 20, 2017
Kenesto: 30 day trial
SolidCAM: Cutting Webinar



Internet Business Systems © 2017 Internet Business Systems, Inc.
25 North 14th Steet, Suite 710, San Jose, CA 95112
+1 (408) 882-6554 — Contact Us, or visit our other sites:
AECCafe - Architectural Design and Engineering EDACafe - Electronic Design Automation GISCafe - Geographical Information Services TechJobsCafe - Technical Jobs and Resumes ShareCG - Share Computer Graphic (CG) Animation, 3D Art and 3D Models
  Privacy Policy Advertise