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Re: Calculating time to eject liquid from cylinder with nozzle
Re: Calculating time to eject liquid from cylinder with nozzle -- roger5	Post Reply	Top of thread	Forum

Posted by: zekeman ® 12/22/2006, 16:21:48 Author Profile eMail author Edit

You have to write two equations 1) the dynamic equation of force on the plate, F=pA, opposing the initial velocity, V 2) The Bernouli equation involving pressure and velocity thru the nozzle md^2y/dt^2=-pA A*(dy/dt)=a*sqrt(p-pa)/w w = density of water A= crossection of bottle a =area of nozzle If you can't solve this, repost and we can help. Viscosity is not important for water in this system.

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Re: Re: Calculating time to eject liquid from cylinder with nozzle
Re: Re: Calculating time to eject liquid from cylinder with nozzle -- zekeman	Post Reply	Top of thread	Forum

Posted by: roger5 ® 12/24/2006, 10:08:55 Author Profile eMail author Edit

Not really. Could you put some example numbers in please.

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Re: Re: Re: Calculating time to eject liquid from cylinder with nozzle
Re: Re: Re: Calculating time to eject liquid from cylinder with nozzle -- roger5	Post Reply	Top of thread	Forum

Posted by: roger5 ® 12/26/2006, 04:27:26 Author Profile eMail author Edit

You said "If you can't solve this, ..." and my reply was "Not really". I thought it was clear from the way I phrased it. Sorry.

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Re: Re: Re: Re: Calculating time to eject liquid from cylinder with nozzle
Re: Re: Re: Re: Calculating time to eject liquid from cylinder with nozzle -- roger5	Post Reply	Top of thread	Forum

Posted by: zekeman ® 12/26/2006, 09:46:11 Author Profile eMail author Edit

Sorry for the miscommunication. First, if you are saying that the plate has a velocity V, then do you mean that it is the initial velocity that is slowed down after impact with the fluid? That is the assumption I made and the basis for the equations . Otherwise, if you mean that the plate is moving at constant velocity, then the problem is simple and is just the volume of the thing divided by (A*V). Post which, and I think I can solve the set in general terms involving, m and V, if the first case applies.

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Re: Re: Re: Re: Re: Calculating time to eject liquid from cylinder with nozzle
Re: Re: Re: Re: Re: Calculating time to eject liquid from cylinder with nozzle -- zekeman	Post Reply	Top of thread	Forum

Posted by: roger5 ® 12/27/2006, 02:08:10 Author Profile eMail author Edit

>First, if you are saying that the plate has a velocity V, then >do you mean that it is the initial velocity that is slowed >down after impact with the fluid? Yes

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Re: Re: Re: Re: Re: Re: Calculating time to eject liquid from cylinder with nozzle
Re: Re: Re: Re: Re: Re: Calculating time to eject liquid from cylinder with nozzle -- roger5	Post Reply	Top of thread	Forum

Posted by: zekeman ® 12/27/2006, 17:10:48 Author Profile eMail author Edit

I solved the set and got t=(e^(@*L)-1)/(@*V) where t= time to complete evacuation, sec e is the natural base= 2.718... @=w*A^3/(2*m*a^2) L=length of cylinder fluid A = crossection area,Ft^2 a=orifice area, ft^2 w= density of fluid lb/ft^3/g m= mass of plate,weight in lbs/g V=initial velocity of plate, ft/sec g= 32 ft/sec^2 Try this out and tell me what you think or if you have other questions. Good luck.

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Re: Re: Re: Calculating time to eject liquid from cylinder with nozzle
Re: Re: Re: Calculating time to eject liquid from cylinder with nozzle -- roger5	Post Reply	Top of thread	Forum

Posted by: zekeman ® 12/25/2006, 23:47:44 Author Profile eMail author Edit

removed comment Modified by zekeman at Thu, Dec 28, 2006, 14:55:11

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