I am interested in making a very small scraper blade that moves back and forth along a submerged surface, however I need to make it as hydrodynamic as possible so I disturb the liquid as little as possible.

I understand I can model different things such as wings in ANSYS, however most of the tutorials only focus on those that have one direction of travel. I need to design the most efficient shape that will be moved in both directions in a liquid.

I know there are a lot of variables to deal with, but I need some sort of starting point on how to approach the problem. Can anyone offer any suggestions?

Edit: included a picture to explain a bit better.

enter image description here

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    $\begingroup$ It has to have a symmetric cross-section. With that as a constraint, you only have to model it in one direction. $\endgroup$ – Chris Mueller Jan 14 '16 at 13:19
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    $\begingroup$ That is true. However say I model a rain drop like shape (for a simple example), would I cut it in half and use the back end where it trails off, or the front end which is more rounded? $\endgroup$ – user88720 Jan 14 '16 at 13:34
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    $\begingroup$ That isn't the actual shape of a raindrop (based on the balance between internal and external pressures, it's actually shaped more like a hamburger bun, with the flat side being the leading side). However, getting back to your actual question -- you need to be a bit clearer about what you're trying to accomplish. For example, where do you expect the "scrapings" to end up? $\endgroup$ – Dave Tweed Jan 14 '16 at 16:32
  • $\begingroup$ It is to be used in a 3D printer to remove UV curable resin from a glass surface before it actually cures by a projected light source shining through the glass. It takes around a second for it to cure, so I plan to have a wiper blade (about 500 micron thick) moving along the glass at 500mHz which will basically push away the liquid that would otherwise be curing to the glass, away from the surface. The goal is for the flow to be completely laminar so as not to disturb the layer where I want the resin to cure, which is about 1 mm from the glass. $\endgroup$ – user88720 Jan 15 '16 at 2:05
  • $\begingroup$ What? Why is the resin getting on the glass to begin with? Maybe you should draw a diagram -- it would be a lot clearer than trying to describe your printer's setup with words. $\endgroup$ – Dave Tweed Jan 15 '16 at 14:24

You would have to have a raised edge to catch the excess material which will cause some turbulence, the amount of material would dictate the height of the raised edge. Unless there is a material that will naturally attract the media being used, really don't see a way around it. I would try a blade with either side angled upwards towards the middle with a flat bottom and a channel on the top side in the middle that is just above the liquid to prevent turbulence on the trailing end that leads to a runoff area to the sides of the tank. The rate of travel will dictate angle as much as the depth and width of the channel. It can also be cammed in the middle so the trailing edge either way will raise some. Or looking from the top of the rectangle blade the raised portion could be a diamond in shape leading to the runoff area, more turbulence but easier to make.


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