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phetsims / fluid-pressure-and-flow

"Fluid Pressure and Flow" is an educational simulation in HTML5, by PhET Interactive Simulations.
GNU General Public License v3.0
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User feedback - volume flow rate when cross section decreased #318

Open oliver-phet opened 6 years ago

oliver-phet commented 6 years ago

I want to say that IMHO there is one small problem which leads to misconception, in the simulation of water flow through a pipe. I mean the application called "Fluid Pressure and Flow" - part called "FLOW". Please read the next paragraph carefully, because if you don't, you might think like i do not understand the basics- that Q stays same even though pipe changes its cross section. Well' it is not what i am going to say.

What i am saying, is that in the very moment when you decrease (locally) cross section of a pipe, the Q all over the pipe will decrease. YEP it will stay same Q in all parts of pipe, but it will be lower then it was before the change, so if i start with Q=5000' and suddenly i make the pipe more narrow, the Q should change to (let say for example) to 3500. You can even add water pump to the left side of screen, and let user to adjust pumps "power" if a user wants to get the Q back to 5000.

gl-man commented 6 years ago

Input, output, system parameter (2 must be fixed while the other is variable. There should be options for fixing any combination) a. Water is sprayed at a certain velocity through a hose, assuming entirely smooth flow. b. Depending on the size of the opening, the stream has a certain speed. This is a simple equation, Q = VS, where Q is volumetric flow rate (cubic meters/second), V is velocity (meters/second), S is surface area (square meters/second). c. Allow the student to change one of the main measures while showing the effects on the other two. d. Input- water at one speed e. Output- water at another speed f. System parameter- size of opening g. Make sure to lock one variable at a time and allow one variable to be changed at a time. Students can choose which to lock and which to change. For example, fixing Q and changing V causes S to change. Fixing V and changing S causes Q to change. Etc. h. We are emphasizing the EFFECT on ONE VARIABLE by CHANGING ONE and FIXING ONE.

gl-man commented 6 years ago

Are you working on this?