![]() In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Nothing to apologize to me about, just learn the rules and abide by them. Ask questions and participate in the discussion, but don't post "please explain the equation on page 67 of my book" kind of questions ever again. When it happens just go with the flow and don't post homework questions again. I'm sure someone will come across your uploaded files and ask site management to delete the thread. Probably very little that can help with school work (mores the pity), but a ton of stuff to help with a career. And we argue a lot about the nuances of those seemingly tiny differences. The white-hairs on this site are mostly guys who are regularly asked to differentiate really light gray from slightly darker gray. There is a lot for someone to learn on this site, mostly that there is a point in your career where things suddenly stop being black and white and you find there are so many subtle shades of gray. When you posted scans of your text book there stopped being any chance of ignoring the fact that this was homework. When you posted your question, there was a reasonable chance it was work related and I didn't ask. Recently the site management has implemented a don't ask/don't tell policy. It used to be that any student post got the student removed from the site. RE: Mass flowrate and pressure at subsonic and supersonic speeds zdas04 (Mechanical) 14 Feb 15 14:01 I started to draw it as "S" shaped, but that implies knowledge that I simply do not have. I have no idea what that flow profile looks like and from extensive research I'm pretty sure that no one else does either. The straight line in the transsonic region is simply connecting the end of one curve with the start of another. Below some value less than Mach 1.0 (based on dynamic pressure changes with velocity I use 0.6 Mach, others use 0.3 Mach), the flow matches the isothermal gas flow equation. Above choked pressure the mass flow rate is linear. This is a plot of the the flow through a hole when supply is shut off. I've attached a slide from my 5-day class that shows what he's talking about. Galileo Galilei, Italian Physicist RE: Mass flowrate and pressure at subsonic and supersonic speeds zdas04 (Mechanical) 14 Feb 15 13:58 With everything except upstream pressure held constant (the friction factor is not constant, but is pretty close for small changes in upstream pressure) then the mass flow rate term will approximate a parabola (but will deviate because of subtracting the downstream pressure and the changes in the friction factor). ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |