2 replies to this topic

[Jackson Sim]

hi, i currently have an assignment on reynolds number. I am stuck in one question. The question is " At a reynolds number of 10000 in a baffled tank (4 baffles), will the power requirement be affected if the viscosity of the liquid is changed? Prove it mathematically to justify your answer."

I know the answer is that the changes in viscosity will not change the power requirement as the changes are too insignificant. However, i am unable to explain mathematically because from what i know, the equation of the power function do not have any viscosity in it.

Any help is appreciated, thank you.

[gvdlans]

We are not interested in doing your homework or your exams.

What you can try is to write exactly what you did and maybe you can generate some hints on how to proceed.

"I know the answer is that the changes in viscosity will not change the power requirement as the changes are too insignificant."
How do you know that the changes are too insignificant?

"However, i am unable to explain mathematically because from what i know, the equation of the power function do not have any viscosity in it."
If the equation of the power function does not have any viscosity in it (as you state), isn't that the mathematical proof you have to give?

What is the equation of the power function in your opinion?

Maybe my questions will help you in finding your answers...

[suhas]

Hi jackson..

Just don’t think mathematically... u r not a mathematician but you are an engineer.. pls try to think practically... and think logically... On what basis you are saying that there is no change in power requirement... think yourself,

Think that you are stirring water and paint with the same Reynolds number... are you expecting that you will require the same power..?

I think this will give you the answer....
and now then think how to get it mathematically.. and what are you missing in equation..?