bertusgeert 1 #1 February 12, 2006 I was talking to a friend the other day about fluid mechanics, and the fundamental equations. All I remember is something like: Inflow - outflow = generation - destruction What is the correct equation, and what is it called? --------------------------------------------- As jy dom is moet jy bloei! Quote Share this post Link to post Share on other sites
cocheese 0 #2 February 12, 2006 Gallons per minute through a pipe.gpm= .0408 x pipe diameter inches2(sq) x feet/minute water velocity ? Quote Share this post Link to post Share on other sites
sundevil777 94 #3 February 12, 2006 QuoteI was talking to a friend the other day about fluid mechanics, and the fundamental equations. All I remember is something like: Inflow - outflow = generation - destruction What is the correct equation, and what is it called? That is not fluid mechanics, that is just conservation of matter or something like that. However, maybe you are referring to the Navier Stokes equations. A simple search on this term will get you going.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
larsrulz 0 #4 February 13, 2006 QuoteI was talking to a friend the other day about fluid mechanics, and the fundamental equations. All I remember is something like: Inflow - outflow = generation - destruction What is the correct equation, and what is it called? Could you be a little more general? I assume you're talking about Reynolds transport theorem (of which the differential forms make up the Navier-Stokes equations, and given you are talking about fluid mechanics, this is probably the case), but who knows. It applies to any logical conservative property, i.e. mass, momentum, energy, heat. I recall it moreso in my thermo classes, but that's probably because I tended to fall asleep in my fluids classes. In fact, you can't destroy a fluid, so this seems more thermodynamically likely unless we are talking theoretically. I got a strong urge to fly, but I got no where to fly to. -PF Quote Share this post Link to post Share on other sites
waltappel 1 #5 February 13, 2006 Look, this is the bonfire. Let me try to get things back on track here. This is probably more along the line of fluid dynamics but I've always wondered what the deal is when I'm taking a piss and get like three streams coming out in different directions--one in the toilet, one on my leg, and one on the ceiling (or whatever). Since when did the bonfire become a haven for intellectualism! Gee. Walt Quote Share this post Link to post Share on other sites
Trae 1 #6 February 13, 2006 in reply to "All I remember is something like: Inflow - outflow = generation - destruction " .................... I seem to recall that all the fluid dynamics equations are mere approximations of the 'real ' world. just love (NOT ) how those scientists think it's OK to reduce everything to imperfect equations and then apply them so astutely to our world . It's little wonder modern technology misses out on taking everything into account eg all the toxic by products ....not included in those imperfect equations No doubt everything is flowing close to estimate down and through all them pipes. Quote Share this post Link to post Share on other sites
kallend 1,658 #7 February 13, 2006 Quote I seem to recall that all the fluid dynamics equations are mere approximations of the 'real ' world. just love (NOT ) how those scientists think it's OK to reduce everything to imperfect equations and then apply them so astutely to our world . It's little wonder modern technology misses out on taking everything into account eg all the toxic by products ....not included in those imperfect equations No doubt everything is flowing close to estimate down and through all them pipes. You'd better stay on the ground - all modern airplanes are designed using those imperfect equations.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
pincheck 0 #8 February 13, 2006 Quotewhen I'm taking a piss and get like three streams coming out in different directions--one in the toilet, one on my leg, and one on the ceiling (or whatever). Isn't that an old Jedi mind trick All this to win a pissing contest Billy-Sonic Haggis Flickr-Fun Quote Share this post Link to post Share on other sites
skiskyrock 0 #9 February 14, 2006 QuoteI was talking to a friend the other day about fluid mechanics, and the fundamental equations. All I remember is something like: Inflow - outflow = generation - destruction What is the correct equation, and what is it called? This is mass balance, not fluid mechanics. The equation might be right or wrong, depending on the control volume and sign conventions. And you have to account for accumulation: Inflow - outflow = generation + destruction + accumulation drink enough beer and you'll either piss or explode ~ Quote Share this post Link to post Share on other sites
