View Single Post
  #9   Spotlight this post!  
Unread 08-01-2017, 08:51
Ether's Avatar
Ether Ether is offline
systems engineer (retired)
no team
 
Join Date: Nov 2009
Rookie Year: 1969
Location: US
Posts: 8,125
Ether has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond reputeEther has a reputation beyond repute
Re: Terminal Velocity of the Fuel Balls

Quote:
Originally Posted by AMendenhall View Post
I don't think aerodynamics will be useful for modelling flight paths of fuel; the holes will let air through, and even if the interaction is significant, it wouldn't be practical to model internal air flow
You don't need to model airflow in order to build a useful simulation. All you need is some good data.

For any team so inclined, here is an opportunity to provide a useful service to the community

Place the cannon against a block wall (a gym perhaps) and fire shots along the wall at different elevation angles and muzzle speeds while taking high-speed timestamped videos. Make sure there are no running fans or open doors or windows (to eliminate air currents).

The blocks act as a Cartesian grid for marking 2D (x,y) location.

Using the location vs time data, that data can be fit to a parameterized model to find values for the model parameters which provide the best fit.

Once the best-fit parameters have been experimentally determined, the model can be used by teams to help design their cannons.

I'll volunteer to do the model fitting if the data is made available.


[EDIT] Thinking back to my boyhood, I seem to recall that Wiffle balls exhibit a profound Magnus effect. Topspin and backspin can dramatically affect the flight path. This makes the data collection and modeling quite a bit more difficult and contentious.




Last edited by Ether : 08-01-2017 at 09:11.
Reply With Quote