"Fluid flow control with transformational media"

Discussion in 'Hydrodynamics and Aerodynamics' started by lumberjack_jeff, Aug 12, 2011.

  1. lumberjack_jeff
    Joined: Oct 2010
    Posts: 101
    Likes: 12, Points: 0, Legacy Rep: 99
    Location: Washington State

    lumberjack_jeff Sawdust sweeper

    http://arxiv.org/PS_cache/arxiv/pdf/1106/1106.2282v2.pdf

    Have any of you read the above new paper?

    This sounds interesting but the physics is above my pay grade.
     
  2. philSweet
    Joined: May 2008
    Posts: 2,234
    Likes: 140, Points: 63, Legacy Rep: 1082
    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    Think of a slab sided catamaran with convex inner hull surfaces and propulsion distributed along the tunnel so that the water is accelerated enough cancel any pressure being caused by the hulls motion. Pressure sensors can quickly respond to changing conditions. Tilting the slipsteam of a waterjet downwards is one response possibility. You can not only mitigate induced waves, you can flatten the seaway inside the tunnel a bit as well. There are scads of old patents that seem to revolve around this idea. Have never seen any test data though.

    Ok, I read the paper. They are basically saying the same thing. By carefully distributing some propulsion and diffusion around an object, the flow outside the area you are fiddling with is unaffected by the passing of the solid object. What they don't address is the propulsive efficiency of such an effort. If you are primarily concerned with satelites tracking ships' wakes, it could be interesting. They've done a hell of a job of obfuscating some not that difficult math. They came at it from a previously solved electromagnetic cloaking problem (which really is a ***** given the properties of available materials). Years ago I did something similar. I wanted to cancel out the wake of oncoming or passing semis on each others' trailers. Same basic problem but it was the effect of other guys' wake I was trying to get rid of, not my own. It takes a lot less power to occasionally cancel each others wake than for everone to cancel their own all the time. The usefulness of the model mostly relates to making guesses about how a control system would be set up for a mechanism that consists of just a few parts.
     
Loading...
Similar Threads
  1. Patrick Hickey
    Replies:
    64
    Views:
    3,489
  2. ImaginaryNumber
    Replies:
    4
    Views:
    2,165
  3. arun_naval
    Replies:
    2
    Views:
    1,327
  4. khabiran
    Replies:
    9
    Views:
    3,109
  5. mtumut
    Replies:
    8
    Views:
    1,949
  6. sinmania
    Replies:
    0
    Views:
    1,225
  7. Janne Enlund
    Replies:
    41
    Views:
    3,776
  8. johan gronvall
    Replies:
    33
    Views:
    5,169
  9. rwatson
    Replies:
    1
    Views:
    1,856
  10. Vinassman
    Replies:
    12
    Views:
    4,191
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.