High Viscosity Flow Through an Orifice
High Viscosity Flow Through an Orifice
(OP)
Hello,
I am designing a closed hydraulic cylinder with high viscosity fluid. The piston in this cylinder forces fluid through orifices in the bottom of the cylinder, then up through a fluid return cylinder, finally back into the piston area through the same size orifice in the top of the cylinder.
I am having difficulty determining the appropriate size of the orifice.
What I do know is:
constant pressure on the piston
piston size
fluid properties
It seems reasonable to assume that by varying the orifice size I can find the appropriate speed I wish the piston to move.
Any suggestions or help would be greatly appreciated
Thanks!
I am designing a closed hydraulic cylinder with high viscosity fluid. The piston in this cylinder forces fluid through orifices in the bottom of the cylinder, then up through a fluid return cylinder, finally back into the piston area through the same size orifice in the top of the cylinder.
I am having difficulty determining the appropriate size of the orifice.
What I do know is:
constant pressure on the piston
piston size
fluid properties
It seems reasonable to assume that by varying the orifice size I can find the appropriate speed I wish the piston to move.
Any suggestions or help would be greatly appreciated
Thanks!





RE: High Viscosity Flow Through an Orifice
Isn't that going to cause a problem with schedule?
RE: High Viscosity Flow Through an Orifice
Dan
www.eltronresearch.com
Dan's Blog
RE: High Viscosity Flow Through an Orifice
RE: High Viscosity Flow Through an Orifice
I should have attached a sketch originally, but here it is.
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ProE drawing, colored to make it easier to see. Dark blue is fluid, light blue is the orifice. The rest of the body and piston is solid and sealed.
The cylinder is a very small damper, about 3" max height and 1" max bore size. The orifice total area per half of the cylinder will be less than 1/2" over 4 orifices, making each hole a mere 1/8" area.
The orifice values I just mentioned are my best guess on what I need based on the velocity I wish the piston to move when about 50psi is exerted on it.
However, I am looking for mathematical background for these guesses. My goal is to graph the average velocity of the piston over 1" displacement as it relates to the orifice size (simplifying my future decisions).
I am also assuming the temperature does not change, for ease of calculations, possibly to be looked at again in the future. Also there time dependent situation such that the velocity of the piston will not instantaneously change due to a pressure build up at the orifice. So an average velocity will do for now but any help into that next level would also be appreciated.
Thanks again for any additional help
RE: High Viscosity Flow Through an Orifice
RE: High Viscosity Flow Through an Orifice
RE: High Viscosity Flow Through an Orifice
Yes, but you are drawing the wrong conclusion. You need to review how hydraulic systems, and especially cylinders, work.
Mike Halloran
Pembroke Pines, FL, USA
RE: High Viscosity Flow Through an Orifice
Mike Halloran
Pembroke Pines, FL, USA
RE: High Viscosity Flow Through an Orifice
As suggested, you need to research and understand how hydraulic cylinders work. Here is a start: htt
Ted