MEng project: paddle blades with holes

Hello there,

Firstly, Merry Christmas to everyone - I hope you are all having an enjoyable one.

Secondly, for those of you who are interested, I thought I would put up a wee update on my paddle project. For those of you who don't know what it's about, a quick explanation. My idea is to put holes in paddle blades to encourage flow through the blade, to dissipate the horse shoe shaped vortex (the whirlpools you see when paddling are either end of this), because there is a lot of energy involved in creating this vortex. In short, my idea is to reduce the size of the vortex, therefore reducing the energy that has been consumed in creating that vortex. So although the force will be reduced from reducing the blade area, hopefully more will be gained from putting less energy into the water, so hopefully, the net effect will be a more efficient paddle. If it works, because of the effects on the strength, it think it is likely that the paddle will be most suitable for long distance touring.

Using computational fluid dynamics (CFD) analysis I can measure the turbulent kinetic energy in the water - a visual representation of my CFD analysis so far is shown below, illustrating turbulent viscosity for a paddle blade with no holes and 25mm holes respectively, in the vertical position.












As can be seen from the images, there is less turbulent viscosity occuring in the paddle blade with 25mm holes, therefore it can be concluded that less energy has been put into the water. Turbulent viscosity plots are likely to be good indication of turbulent kinetic energy. The turbulent kinetic energy is related to the amount of energy that has been put into the water.

A few thoughts:
- please understand that my project is not finished, and these are only preliminary results and I have not fully investigated the effects yet
- the CFD analysis only considers the blade in vertical position
- there are a number of other significant simplifications made for practical and time constraints
- holes may have significant effects on the entry and exit motion of the blade
- more in depth CFD analysis would give a better idea of the effects
- more work could be carried out on optimal hole size and configuration
- I am looking into patents, and will hopefully have it sorted early in the new year
- in the end, if this design works, I would like it to be accessible to everyone, so that they could take their cordless drill and modify their paddle to make it more efficient, however, regarding business, if anyone is going to make any money from it, I would like it to be me, hence why I am sorting out a patent

I would greatly appreciate your thoughts and advice on anything you think you can help with.