This post seems to have taken on a life of its own. ; )
As the original poster, I actually don't need anymore input..I got all I need! Thanks, and on to the next question! ; )
It would be quite impractical to test the telescopes at 1 psi pressure. Mechanical designers specify maximum pressure and provide that to me. Reasonable suggestion but not really feasible or necessary.
My philosophy is to try to understand the theory and combine that understanding with experimental results specific to the problem I am trying to solve. The posts have provided me food for thought and I am now better able to understand the problem and have been getting experimental results which...
Scialdone assumes an isothermal process as the launch is pretty fast (order 100 seconds). And I misspoke when I said that an orifice had a different dependence. I was looking at dependence for a circular pipe.
I agree with you, Latexman. What makes me kind of crazy is that Scialdone in that reference you gave me gives a dependence of dP/dt on sqrt(deltaP * P). Analytical equation for flow through a simple orifice shows a dependence of dP/dt on P and sqrt(expression of ratios of upstream and...
Thank you, Latexman. I had a copy of that and had been so frustrated with the poor copy quality, but I did take another gander at it. Alot of great stuff in there....although "area" still has to be determined for any vent which is not a straight shot hole.
OK, what I'm hearing is that if I measure a mass flow of 1 g/sec flowing across my orifice for a fixed upstream pressure of 15.7 psi and a downstream pressure of 14.7 psi, THEN I expect to get 1 g/sec flowing across my orifice with an upstream pressure of 5.7 psi and a downstream pressure of 4.7...
I am also enjoying this thread. More comments. Amazingly, there is only one article in the literature that I have found on flow through orifices at reduced pressures, and the famous rule of thumb of venting 1 cubic foot through a 1/4 inch diameter vent. The whole aerospace industry uses that...
Thanks again to all of you. I read more of Milton's link, and it looks like mass flow depends on the square root of the product of density and upstream pressure, not square root of product of density and delta P...This isn't what 25362 posted. The full equation in Milton's post does have...
Thank you very much for your replies. I took a look at the links and they don't quite fit my question. I don't think that the gas flow in my case is necessarily choked, although I could be wrong. I think it would be helpful to explain my application a bit more. I am studying the venting...
I am trying to understand the effect of ambient pressure on venting a gas from a pressurized vessel. I understand that conductance of an orifice has units of torr-litre/sec. Does this mean that if there is a pressure difference of 1 psi, regardless of the absolute value of the input/output...
