vortex generator (VG)

vortex generators, tubercles, whale flippers, wind turbine

https://www.apnews.com/15fbb89ba9b84aa0bed18c91033d1ddc
South Dakota students win $10K for fuel-efficient invention
April 30, 2019

Vortex generator devices are most commonly used to reduce drag on airplanes.

0:44
Vortex Generators Explained in 30 Seconds!
https://www.youtube.com/watch?v=dr_G4hbXSLQ
https://www.youtube.com/watch?v=dr_G4hbXSLQ
KYLE.ENGINEERS
Published on Aug 21, 2016
How do vortex generators work? Vortex generators are used on EVOs, F1 cars and aircraft, A vortex generator is an interesting piece of tech, that a lot of people don't actually seem to properly understand. In this video I quickly cover the basics of vortex generators

4:51
How do Vortex Generators Work?
https://www.youtube.com/watch?v=eP-YUDe9HF0
https://www.youtube.com/watch?v=eP-YUDe9HF0
Samm Sheperd
Published on Nov 15, 2015

8:27
How do Vortex Generators Work?
https://www.youtube.com/watch?v=9Whd_KnsLKE
https://www.youtube.com/watch?v=9Whd_KnsLKE
KYLE.ENGINEERS
Published on Jul 3, 2014
Kyle is back with a beard and a new look to teach y'all about vortex generators! Used on EVOs, F1 cars and aircraft, VGs are an interesting tech, that a lot of people don't actually seem to properly understand....


https://www.bing.com/images/search?q=whale+flippers

tubercles
whale flippers
https://en.wikipedia.org/wiki/Tubercle_effect

google search (images)
tubercles airplane

airplane wing, submarine, race car airfoil, wind turbine, kitchen knife, pump   

0:51
Whale Fin Turbines
https://www.youtube.com/watch?v=OvNWKMHSzQ4
https://www.youtube.com/watch?v=OvNWKMHSzQ4
Valhalla Agency
Published on Jul 18, 2017

3:28
Fluid analysis of a humpback whale fin
https://www.youtube.com/watch?v=dz39guNxAc4
https://www.youtube.com/watch?v=dz39guNxAc4
siddharth shah
Published on Nov 15, 2015

12:24
Amazing Technologies Inspired by Nature
https://youtu.be/_5i_QJyL3mI?t=669
https://youtu.be/_5i_QJyL3mI?t=669
https://www.youtube.com/watch?v=_5i_QJyL3mI
https://www.youtube.com/watch?v=_5i_QJyL3mI
BE AMAZED
Published on Apr 23, 2017
There's a test lab that's been running intensive R&D that you can turn to for ingenious solutions. Prepare to be amazed by these top 15 examples of biomimicry - tech inspired by nature.

1:42
What Can a Humpback Whale Teach a Wind Turbine? | Think Like a Tree
https://youtu.be/FMG5Ah1g8rM?t=33
https://youtu.be/FMG5Ah1g8rM?t=33
https://www.youtube.com/watch?v=FMG5Ah1g8rM
https://www.youtube.com/watch?v=FMG5Ah1g8rM
WIRED
Published on Nov 19, 2015

6:48
Theory of Constraints (TOC) 3 Bottle Oiled Wheels Demonstration
https://www.youtube.com/watch?v=mWh0cSsNmGY
https://www.youtube.com/watch?v=mWh0cSsNmGY
Arrie van Niekerk
Published on Jul 5, 2012
 

https://www.bing.com/images/search?q=vortext+generator+wing+tip&form=HDRSC2&first=1&cw=1129&ch=762


https://www.ingenia.org.uk/Ingenia/Articles/b8e6d8ae-101d-4c44-91d6-5be05cb78e49

Yet while developing his revolutionary propulsion system, Parsons struggled to convert the power generated by his steam-driven turbine into forward momentum – something was sapping the energy from his propeller, preventing his experimental ship from achieving the speeds he had expected. For some reason, his vessel could only manage a speed of 19 knots when his calculations suggested it should be able to achieve a top speed of 40 knots.

Sir Charles, as he later became, discovered the culprit was ‘cavitation’. As a propeller rotates at high speed, it can cause the water behind it to essentially boil, creating bubbles, or cavities, to form in the water. This wastes energy rather than helping to drive the vessel forward.

Nearly 140 years after Parsons discovered the problem, however, cavitation is still posing challenges for ship designers, passengers and crews. Over time, it can ruin propellers by eroding the metal and is responsible for a large amount of the noise and vibration experienced on modern ships – see Cavitation explained.

Parsons attempted to overcome his problem by building one of the world’s first cavitation tunnels.

   ... ... ...

That first cavitation tunnel, however, is dwarfed by modern facilities, that have sprung up around the world. Among the largest is the Large Cavitation Channel in Memphis, Tennessee, where the US Navy tests its latest submarine and surface ship propulsion systems.

Rolls-Royce has one of the busiest cavitation tunnels in the world at its Hydrodynamics Research Centre in Kristinehamn, Sweden. Operating for more than 70 years, it has tested more than 1,500 different propeller designs and conducts around 40 new tests each year. The site has a traditional cavitation tunnel with a volume of 117 m3, and a second, free-water surface containing almost 400 m3 of water. Together, they have allowed Rolls-Royce to become one of the leading centres of research into propeller design and ways to reduce the cavitation that plagues them.


https://www.aquamcorp.com/pages/pipe-cleaning-4.html

The anatomy of tubercles: A corrosion study in a fresh waterestuary
Dedicated to Professor Dr. Wolfgang Sand on the occasion of his 60th birthday
R. I. Ray, J. S. Lee, B. J. Little* and T. L. Gerke
https://www.d.umn.edu/biology/documents/Oster1.pdf

The structure and mineralogy of corrosion products formed on carbon steel coupons exposed in Duluth Superior Harbor (DSH, USA), were investigated and compared with corrosion products on similar substrata from other locations. Corrosion products in DSH form within a few months each year and are removed by ice scour and reform. The corrosion products formed in DSH are tubercles with an outer surface, an inner shell of magnetite, and a core of iron(III)oxyhydroxides, goethite, and lepidocrocite, in association with stalks produced by bacteria. In general, the tubercles formed in DSH are similar in morphology and mineralogy to corrosion products described for carbon steel and cast iron exposed to treated waters in decades-old drinking water and cooling water systems. DSH tubercles are unique in several structural details. DSH tubercles increase areal coverage of the substratum by consolidation of tubercles. Furthermore, the core material extends into the pit and is an exact replica of the pit profile.

1 Introduction

The term tubercle, meaning a small rounded prominence, has been used to refer to iron corrosion products on steel surfaces exposed in treated (i.e., chlorinated and heated) fresh waters.