chicopee and Sch10Sean, thank you both for your answers. If I understand you correctly you both say that the force is directed in the same direction as when the pipe discharges. That is really interesting because it is the opposite what to expect using the momentum change method that is used...
If you simply want a rough estimate you could, at least for small opening percentage, assume that the flow is a ideal nozzle. Assuming no pressure recovery (P_throat=P2) the pressure drop can be calculated according to
dP = 0.5*rho*Q^2*(1/Ac^2 - 1/A1^2)
(Ac=throat area, assume physical...
Hello, this is perhaps a stupid question but my mind is playing tricks on me.
At a discharge pipe outlet a stationary force equal to F=m*V creates a bending torque at the support.
If the flow is reversed - what force/torque is developed and in what direction?
Please see attached figure
Thanks
Hi, I need to determine the built up back pressure from relieving subcooled water. The water flashes in the short oulet line. Which formulas can be used to determine this pressure?
Thanks
I forgot to post my pretty picture in the previous post. Here it is.
BigInch, I agree that the depressurization rate should be very fast and not important to the total time it takes to drain the outlet. I would guess that the outflow from the pipe would be less intermittent than that from a...
Ok, I am not sure I am getting the same result on my google search as you (Google search result is nowadays personal/dependant on past search queries). Can you specify what I should look for?
Meanwhile, what I expect is this.
1) at t=0 the pipe is filled with water. The upstream end is a...
Hello,
I want to get a estimate on how fast the outlet line of a safety/relief valve is drained. The outlet line is rather long and the fear is that the bellow can get damaged if the valve experience a subsequent opening. The medium is water (cold)
Can anyone point me in the right direction...
@ ione
Thank you for the reply. However, I am also interested in this question beside my task at hand (so the conservative value isn't "good enough" :) ). If the recovery factor is 0.89 then the wall temperature, assuming isolation on the outside, is:
(273.15 + 10) - (1 - 0.89)*189.83/(2 *...
Hello, I doing a thermal expansion analysis on a nitrogen supply line for a expansion tank. I am doing two calculations. One in hot conditions and one in cold conditions. The hot temperature is known and is no problem. The problem is the cold case.
The system consists of a nitrogen tank of...
Hello, I am doing a surge analysis of a empty spray system. The system consists of a high riser-line (vertical pipe) connected to a horizontal spray nozzle header. The riser line is drained before the pump is started. When the pump starts the pipes fill up. As a first assumption I assumed the...
