What is CABS?

This site will help high school students and teachers find original, independent science research topics and questions that can be done without a professional lab...these can be done in a school lab or even in one's basement! The project ideas and research questions being developed and presented here have been vetted and could lead to true discoveries, and not just finding already known results. See our Welcome message. These are the types of projects that could be done and submitted to high school contests such as the Regeneron Science Talent Search, Junior Science and Humanities Symposium, or the Regeneron International Science and Engineering Fair, and be competitive. If you have an idea to share, or a question about one of the project ideas, contact us at vondracekm@eths202.org.

Pages (on the right side of the screen) have lists of ideas for different types of science research projects, and clicking on one of those ideas will take you to posts with details and all sorts of information about that type of project. Get more information about why there is a need for CABS!

Friday, December 29, 2017

Fluids in rotating systems - Example, what happens to hydraulic jump on a rotating surface?

Fluids are challenging because of our lack of understanding of the details of turbulence, a chaotic, random process of fluids of all types. One way to introduce turbulence into fluid flow is through rotations, and the currents produced within fluids due to the rotation. 

This could lead to numerous possible experimental setups and research questions. Think about, as a primary experimental design, using old turntables to mount a surface and rotate it. One could also use drills with variable speeds, and connect surfaces to the drill. Be creative and design and build a structure that will hold a drill in place, and attach the surface (perhaps flat pieces of plastic or vinyl, for instance).

One other interesting option is to experiment with using rheoscopic fluid mixed with water. This is interesting because you may be able to see and video flow patterns that arise. 

As is the case for most 'basement science' experiments, the primary data collection will be with video. If you have cameras that do high-speed video collection, this is ideal. Be sure to have, in your experiments, some measuring device or scale(s) that allow you to determine and measure distances and possibly times when it comes to video analysis. Using software such as Tracker allows you to do video analysis frame-by-frame, if your phone or camera does not do this.  

Possible Experiments and Research Questions:

  • Hydraulic jump on rotating surfaces: What happens to a hydraulic jump when the water jet lands on a rotating surface? Do different patterns or characteristics arise as a function of rotational speed? Try other liquids for the jets and compare/contrast what happens, as a function of density and viscosity.
  • One could attach petri dishes or other containers on the rotating surface. Many options arise for experiments: start with the petri dish empty, and have a water or other liquid jets fall into the dish as it rotates. What happens initially, and what happens as liquid begins to fill the dish? One could vary the rotational speed, flow rates of the jets, and any other parameters that are involved in your design. 
  • Is it possible to rig a rotating surface on angles? This may produce new types of patterns and behaviors of the hydraulic jump, or whatever else a fluid does when hitting a rotating surface with gravity now an influence. 
  • What happens if two different fluids are involved? For instance, one could have a petri dish partially filled with water, and a jet of some type of oil falls into it, with and without rotation of the dish. Or a thin layer of oil could start in the petri dish, and a jet of water falls into it, with or without rotation of the dish. Is there any sign of a jump, depending on the depth of the initial liquid layer? What strange patterns emerge as the water-oil 'mixes' and/or separates? 
  • Start with layers of liquids, such as a layer of water with a layer of some type of oil on top, at rest. What happens when this setup is rotated, as functions of rotational speed, depths of layers of water and/or oil, and diameter of the dish or container? What happens if a jet of oil or water falls into this system, both with and without rotation? 
  • What happens to any of the above rotating experiments, when the rotating platform or dish has rough surfaces? Or patterns of grooves, bumps, obstacles arranged in various patterns, or curved rather than flat surfaces? Think of all the variations on a theme one could dream up and try, each of which would be a new set of experiments and research questions. We are not aware of any experiments that have been done for these types of rotating experiments.
  • What would happen to any of the above rotating experiments if granular materials were involved? For instance, what if there was a petri dish or container on the rotating surface that starts off with thin layers of sand, various sized plastic beads, or other granular material covering the surface? What would happen when different liquid jets fall into the granulars? 
This could be a rich source of numerous, original fluid experiments and projects! 

No comments:

Post a Comment