Fluid problem

[snã¦ss]

Hello!

I'm new to fluid problems and was wondering of someone could point me in the right direction.

My problem is essentially a syringe. If the pluger is pulled by a force (300kN) how much damping will it experience? Initially the plunger is at h = 0 and ends at h = 30 mm when the plunger is out of the cylinder.

D1 and D2 = diameters

[vlehner]

Hi Sigurd,

do you mean viskosity-damping?

if the Force is constant and if we have no air because of the pluger is pulled to hard (Force F), you could solve the problem with the equation of Bernoulli.

You should check, if the Force F=300kN is to much force for your application (see attachement)

I calculated the velocity of the pluger.

Hope the attached File (MathCad Prime 4.0) helps you a bit.

Best regards, Volker

[Fred_Kohlhepp]

I believe that when you start pulling the piston the water behind the piston will flash to vapor, and most of the retarding force you hope to realize by restricting the fluid in won't materialize.

Attached

[snã¦ss]

Thanks guys !!

regards
Sigurd