How to find velocity of gas pump flowing into car tank

AI Thread Summary
To determine the velocity of gas flowing into a car tank, the discussion emphasizes using the general balance equation while considering factors like cross-sectional area and mass flow rate. Participants suggest measuring the volume flow rate in gallons per minute and dividing it by the hose's cross-sectional area for accurate calculations. They also recommend using a stopwatch to time the delivery duration for practical measurements. Concerns about DIY systems and safety are raised, highlighting the importance of relying on established pump specifications. The thread has remained inactive for over two years, indicating that the topic may be concluded.
medale14
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Hello, so I am stuck with the concern of making an equation that fits my standard. I'm trying to create an equation from the mass, momentum and energy balance equation according to my system. My system is a gas pump flowing into a car tank. In this to make it easier for myself I disregarded friction. I understand that to solve this equation I must use the cross-sec area of the nozzle. However, I'm stuck with how to set up the rest of the equation. Would I take inconsideration p atm?
The general balance equation is as follow: d[m{u+gz+v2/2)sys=(u+gz+v2/2)dmin-(u+gz+v2/2)dmout +dq+dw.

I understand that I would take in consideration the cross sectional area as well as the mass flow rate. However I can't figure out what else to consider as if atm pressure should be considered and vapor pressure? My main goal is to figure out the velocity if the gas being pumped into the tank.

Screenshot 2022-10-13 183213.png
 
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Let's just pump water first. Vapor pressure for gasoline might be an issue but not now. So what are you tryimg to specify?
Pump pressure required to deliver a certain flow rate? Please specify exactly what you want to know
 
I'm just trying to figure out an equation that can help me figure out the velocity for pumping gas into a car tank.
 
medale14 said:
I'm just trying to figure out an equation that can help me figure out the velocity for pumping gas into a car tank.
Can you please define all of your terms in your equation in your first post? And in the future, please try to post math in LaTeX (see the LaTeX Guide link in the Edit window). Thanks.
 
medale14 said:
I'm just trying to figure out an equation that can help me figure out the velocity for pumping gas into a car tank.

Measure the volume flow rate (gallons per minute - with a stop watch) and divide by the cross sectional area of the hose (e.g. nozzle). Or just look at the specs of petrol pumps for typical volume flow rate. What accuracy do you actually need?
I hope you wouldn't risk a DIY system for doing this sort of thing.
 
1) The pump display shows a running total of gallons delivered.
2) Use a watch with a second hand, or a stopwatch, to measure the delivery duration.
3) Divide the result from 1) above by the time from 2) above.

Note: the OP hasn't been seen since starting this thread, 2 years + 2 months ago.
 
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It seems the topic has run its course and its time to close after waiting for over 2 years for some new responses.

Thank you all for participating here. Hopefully the OP now has a car of his/her own with which to conduct this experiment and others.
 
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