Velocity of Liquid: Pressure & Density Factors

[jonnyr]

I am trying to determine the velocity of a liquid. The density of the liquid is .885 g/cm3. The pressure at which it is being forced is 17236.89 kpa. What else do I need to know? I am looking for a formula to help me in other calculations with different pressures and densities. Thanks in advance for any help.

 

[haruspex]

I assume it is being forced out of a nozzle or hole at that pressure. (Is that the total pressure or pressure above atmospheric?) The main other detail you need is the area of the hole/nozzle, though there is a difference between the measured area and the 'effective' area. That difference can depend on the internal geometry of the container.

 

[jonnyr]

Yes it is being sprayed from a nozzle in this case which is .16mm per hole and a total of 8 holes. The pressure is total.

 

[haruspex]

Correction, you don't need the area - was thinking of a different problem.
Pressure P, velocity V, density D, area A. Power = P.A.V = A.V.D.(V²/2), V2 = 2P/D.

 

[PJC01]

To determine the velocity of a liquid, you will also need to know the viscosity of the liquid, which is a measure of its resistance to flow. This information is necessary in order to use the Bernoulli's equation, which relates the velocity, pressure, density, and viscosity of a fluid. The equation is as follows:

v = √(2(P2-P1)/ρ(1-(μ/ρ)))

Where:
v = velocity of the liquid
P2-P1 = pressure difference between two points
ρ = density of the liquid
μ = viscosity of the liquid

In addition to the density and pressure, you will also need to know the dimensions of the system in order to calculate the pressure difference. This could include the diameter of the pipe or container through which the liquid is flowing.

It is important to note that the above equation assumes that the flow is steady, incompressible, and inviscid (meaning there is no friction between the liquid and the container walls). If any of these assumptions are not met, the equation may need to be modified.

In order to use this equation for different pressures and densities, you will need to gather data for each specific scenario and plug them into the equation. It may also be helpful to use a calculator or spreadsheet to make the calculations easier.

I hope this information helps you in your calculations. Good luck with your research!