Calculate damping coefficient of dashpot from physical dimensions

[JimmyJimmy]

Hi all,

I am trying to calculate the damping coefficient of a linear viscous dashpot/damper given the dimensions of the piston, and the dynamic viscosity of the damping fluid.

I have found this calculator, but does anyone know the equation that it uses?

http://www.tribology-abc.com/calculators/damper.htm


Many thanks,
JJ.

 

[Bobbywhy]

The general equation of motion for a single degree-of-freedom system with viscous damping can be found here. Hope this helps!

https://www.efunda.com/formulae/vibrations/sdof_free_damped.cfm

 

[JimmyJimmy]

Thanks, I was more looking for an equation(s) which allows me to input the physical dimensions of the piston and the viscous fluid in order to calculate the damping coefficient, rather than recorded data of the damper performance.

 

[256bits]

View the source of the web page and you should be able to see the equation used.

 

[alphy]

Dear JJ,

Thank you for your question. The damping coefficient of a dashpot can be calculated using the following equation:

c = 6πηL/A

Where c is the damping coefficient, η is the dynamic viscosity of the damping fluid, L is the length of the piston, and A is the cross-sectional area of the piston.

This equation can also be derived from the equation for the damping force of a viscous damper, F = cv, where v is the velocity of the piston.

I hope this helps. Best of luck with your calculations.

Sincerely,