Pressure drop in hydraulic fluid for a change in volume
Pressure drop in hydraulic fluid for a change in volume
(OP)
Greetings,
This seems on the face of it a simple problem but for the life of me I can't seem to get a grip on it.
I want to determine the pressure in a system after the system's volume has increased. Basically, a predefined volume has it's pressure increased to a certain pressure when this pressure activates a mechanism allowing a piston to stroke which results in a relatively small increase in the system volume.
The medium is hydraulic fluid. My main struggle is how to account for the bulk modulus of the fluid in the calcs.
Any pointers would be greatly appreciated!
This seems on the face of it a simple problem but for the life of me I can't seem to get a grip on it.
I want to determine the pressure in a system after the system's volume has increased. Basically, a predefined volume has it's pressure increased to a certain pressure when this pressure activates a mechanism allowing a piston to stroke which results in a relatively small increase in the system volume.
The medium is hydraulic fluid. My main struggle is how to account for the bulk modulus of the fluid in the calcs.
Any pointers would be greatly appreciated!





RE: Pressure drop in hydraulic fluid for a change in volume
Looking at it with a fresh (ish!) pair of eyes, I used the definition of bulk modulus for K. Re-arranging to give me dP = -V (K/dV) where dP is delta P (change in pressure), dV is delta V (change in volume), V is initial volume and K is the Bulk Modulus. It is then just simply a case of entering the known values on the right hand side to calculate the resulting change in pressure. Why I couldn't see this before I cannot say...
RE: Pressure drop in hydraulic fluid for a change in volume
Then you might want to account for a drop of water, and an air bubble.
Mike Halloran
Pembroke Pines, FL, USA
RE: Pressure drop in hydraulic fluid for a change in volume
Let your acquaintances be many, but your advisors one in a thousand' ... Book of Ecclesiasticus
RE: Pressure drop in hydraulic fluid for a change in volume
RE: Pressure drop in hydraulic fluid for a change in volume
Mike Halloran
Pembroke Pines, FL, USA