Liquid being pushed out of a nozzle - how to calculate it?

[Rob2009]

Hi guys,

I'm relatively new to physics, so please bear with me.

 

Let's image we have a cylinder like this, filled with 8760 mm3 of liquid, with a nozzle on one end and a plunger on the other.

An explosive charge goes off behind the plunger, releasing 45 joules of energy, and pushing the liquid out of the nozzle.

 

 

I want to calculate

1. how far will the liquid go, before dispersing into mist?

2. what is the optimal shape and size of the nozzle, to make the liquid go as far as possible?

 

Where do you think should I start?

 

Thanks!

Edited September 20, 2012 by Rob2009

[Ophiolite]

The distance to go before it converts to mist will be contingent upon the character of the fluid as well as the physical parameters of the experimental set up.

[Rob2009]

The distance to go before it converts to mist will be contingent upon the character of the fluid as well as the physical parameters of the experimental set up.

 

Let's assume that the liquid is alcohol. What other parameters are needed?

 

And one more thing does the conical shape of the front end of the plunger help or basically the result would be the same as with a simple flat plunger?

Edited September 20, 2012 by Rob2009

[Ronald Hyde]

You have to use variational methods, simply because there are so many things can can be varied. Specify ( fix ) everything that can be specified, the viscosity, density, mass of the plunger, etc. You have to set an initial value or values for the size and shape of the plunger too. Then you have to write an equation, or more likely, system of equations, where the

size and shape of the nozzle are treated as variables, and solve for that. But you will have to realize that the fluid doesn't have one exit velocity, as it exits over the time of the

'experiment' its speed will vary.

 

I don't know why but this question reminds me of a true life tale about Thomas Alva Edison. All the movies I seen about him portray his as some quiet, scholarly fellow who

just invents stuff. This was not TAE. There's only one actor who could play him in a movie, and that is Jack Nicholson. And we also know that Jack Nicholson only plays one

character in all his movies, himself. That's exactly how they both are, just themselves, you either accept them as is, or take your leave.

 

Enter TAE as The Joker, because he loved to kid around. He had a mathematician on his staff, and he had a problem. He wanted to know the volume of a light bulb. He also wanted

to know how 'smart' his mathematician was, as opposed to just being knowledgeable in his field. So he brings the shell of the bulb to the mathematician and asks him to come back

with the result. The math guy spent several hours doing integrals and measuring and such and returned to Edison with his result. Whereupon Edison unceremoniously takes the

empty shell, picks up a pitcher of water, pours it in the shell, pours the shell contents in a graduated cylinder, and takes the measurement. He had discovered that his

mathematician could not 'think outside the box'.

[dmaiski]

stream to drop equations:

http://en.wikipedia.org/wiki/Stream_function

 

then you just have the basic equations for motion of an body

http://en.wikipedia.org/wiki/Classical_mechanics#Velocity_and_speed

 

plug what you have in there and you have a rough estimate

 

if you want to be more difficult you can factor in drag, for the drops

http://en.wikipedia.org/wiki/Drag_%28physics%29

 

just input the information you have into the appropriate equations and you have your answer

 

 

[Ronald Hyde]

stream to drop equations:

http://en.wikipedia....Stream_function

 

then you just have the basic equations for motion of an body

http://en.wikipedia....ocity_and_speed

 

plug what you have in there and you have a rough estimate

 

if you want to be more difficult you can factor in drag, for the drops

http://en.wikipedia....g_%28physics%29

 

just input the information you have into the appropriate equations and you have your answer

I wasn't thinking outside the box, and here this guy comes along, who was thinking outside my box, and has a better way. Good job!