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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 Intel 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.

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Wednesday, December 30, 2015

Granular materials and funnels

Topic: Granular materials

Research question: What are the flow and mixing properties of granular materials flowing in funnels of different shapes and sizes?

Materials and Methods Outline:
You will need some sort of fine granular material. This can be sand, small spherical beads of bronze, copper, or other material. You will need some type of fan that can have a focused stream of blown air. Perhaps a hair dryer or shopvac. It is ideal to have something that has multiple options for wind speed.

The other main piece of equipment will be some sort of camera that has video capabilities. Video will be the main method of collecting data and making measurements. The key to making measurements from video is to have a ruler of some type in the video, which can be used to make calibrations within a program such as Tracker or LoggerPro. If you have access to any video hardware with high-speed options, such as on an iPhone 6 or many other cameras (instead of the standard 30 frames per second (fps), some can be turned to 60 fps, 120 fps, 240 fps, or even 480 fps or 1000 fps); note that the clarity and resolution of video gets worse with higher fps values - you will need to experiment with the settings to get the optimal balance for frame rate and clarity to get measurements you trust.

Possible parameters to test, and make your own:
  • Vertical funnel, single stream of grains sliding straight down as a control
  • What if funnel is angled relative to the vertical?
  • Two streams of identical grains sliding down on opposite sides, colliding/mixing properties
  • Two streams identical material, different diameters
  • Properties of falling down the funnel as function of diameter
  • Grains consisting of different materials: changes in flow patterns?
  • Flow properties as a function of angle of funnel
  • Flow properties as function of width of funnel spout
  • Flow properties as function of entry speed of grains
  • Appearance of avalanches, as a function of flow rate?
  • Have grains flow into funnel at angles so they flow down in spiral motion
  • What conditions must exist to clog the spout? 
  • Piling properties/patterns of grains pouring out of funnel spout into a container: can vary height the grains fall into container; size and shape of container
  • Some of the more interesting analyses would include two (or more) different sized grains, and mixing properties while changing the above conditions and parameters. Any segregation or stratification? 
  • One stream of grains mixing with a stream of water from the other side of a funnel: dynamics of the mixing as a function of flow rates of both grains and liquid; how do the dynamics and mixing vary as the above conditions and parameters are varied?
  • Perhaps some interesting changes in flow occur when the funnel is vertically vibrated at various frequencies and/or amplitudes
An interesting video of computer simulations of granular flow, courtesy of UNC. Get more ideas from what they show! Their website is here.

Links and Literature on this type of research:
- Free-flowing granular materials with two-way solid coupling (UNC math model used in simulations)
Rapid granular flows

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