2004年6月3日 · choked or not, the critical issue is the density flowing through the exit area and the thoughest to estimate(two phase flow is likely). you may be restricted to comparing several scenarios so as to bracket the actual flow. hopefully you have enough metering on the line and can estimate the loss independently.

2009年10月5日 · The adjective “choked” (IMO) should be more properly referred to a particular fluid velocity than to flow (mass) as this condition defines an upper limit for the velocity and not for flow (mass). In choked conditions, the mass flow rate could be anyway be increased as upstream absolute pressure is increased (density increases).

2007年4月16日 · "Choked" implies that the flow experienced is less than the flow predicted by the Cv equation. When the flow measured is 2% less than predicted by the Cv equation, it is said to be "choked". Further reducing the downstream pressure with constant upstream pressure and constant valve position will cause little if any increase in the flowrate ...

2005年7月27日 · israelkk is absolutely right. You've got Choked Flow on your hands since 99% of all compressible flow has a P2/P1 ratio greater than 2 - with the only exception possibly being the A/C industry. I wouldn't apply or refer to any software regarding compressible flow unless I knew exactly what I'm dealing with and the algorithm involved.

2005年1月19日 · Choked flow is also referred to as critical flow or sonic flow when the velocity of the fluid reaches its limiting velocity which is the velocity of sound in the flowing fluid at that location. Typically, flow through a relief valve nozzle will experience critical flow unless the relief valve set pressure is very low (say about 15 psig) or you ...

2008年4月23日 · In isentropic flow (adiabatic + small friction loss), just as isothermal flow, the mass velocity reaches a maximum when the downstream pressure drops to the point where the velocity becomes sonic at the end of the pipe (e.g., the flow is choked).

2001年1月30日 · We are testing a positive displacement pump with water, applying pressure with a control valve. Pressure drop is very high - P1=1500 psig, P2=10 psig. By calculation of choked flow conditions, the max allowable pressure drop is around 1100 psi. Max flow is calcluated around 250 gpm. Actual...

2003年9月13日 · This situation is referred to as "choked flow". If when the downstream absolute pressure divided by the upstream pressure is equal to or less than a number that depends on the ratio of the constant pressure specific heat to the constant volume specific heat of the gas or vapor, then the flow is said to be "choked".

Beychok's thread FAQ378-1201 referenced by zdas04 gives a full explanation of 'choked' flow. If the P(1)/P(2) ratio for an orifice is in the range 1.7 - 2.1 for most gases, the conditions are there for 'choked' flow. Since the velocity through the orifice at choked flow is fixed at Ma 1, the flow is established also: 1129 ft/s = cft/s / sft ...

2004年7月19日 · Both examples of choked flow in my undergraduate fluids book are using elaborate converging/diverging nozzles and you end up with M>1.0. Standard Conditions are mentioned in a problem in the introduction, and once in the fluid-statics section- …