Piston Oscillation in Fluid - Resistance Force
Piston Oscillation in Fluid - Resistance Force
(OP)
I would like to estimate the resistance force applied to a piston that oscillates in a fluid.
Let's say we have a piston with the surface area S that oscillates in water with the frequency Fo and the displacement magnitude Ao, i.e. x = Ao*sin(2*pi*Fo*t).
How can I estimate (analytically or numerically) the maximum value of the resistance force as a function of the frequency for a fixed displacement magnitude?
Thanks!
Let's say we have a piston with the surface area S that oscillates in water with the frequency Fo and the displacement magnitude Ao, i.e. x = Ao*sin(2*pi*Fo*t).
How can I estimate (analytically or numerically) the maximum value of the resistance force as a function of the frequency for a fixed displacement magnitude?
Thanks!





RE: Piston Oscillation in Fluid - Resistance Force
RE: Piston Oscillation in Fluid - Resistance Force
RE: Piston Oscillation in Fluid - Resistance Force
thanks for your comment... but can you, please, be more specific?
Can you please provide a formula along w/ brief explanatory comments or a reference to a book or a paper that could help my resolve this problem?
It's not a homework, it's a calculation task that needs to be performed to evaluate a design potential.
RE: Piston Oscillation in Fluid - Resistance Force
this one is an example
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RE: Piston Oscillation in Fluid - Resistance Force
The usual case is a piston in a semi-infinite baffle. I have also seen a solution for a rigid body in an unrestricted volume, which is a more complicated case.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Piston Oscillation in Fluid - Resistance Force
The reason I emphasise that this is an acoustics problem is that the force required to push the piston is heavily frequency dependent. However if you want to persevere with a velocity based approach then don't forgot the drag along the sides of the piston.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Piston Oscillation in Fluid - Resistance Force
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Piston Oscillation in Fluid - Resistance Force