# How to find velocity of gas pump flowing into car tank

• medale14
In summary, the conversation discusses the general balance equation for pumping gas into a car tank, taking into account factors such as cross sectional area, mass flow rate, and vapor pressure. The main goal is to determine the velocity of the gas being pumped. The equation may need to be adjusted for pumping gasoline, as vapor pressure may become a consideration. The conversation also requests for clarification on the specific information needed, such as the required pump pressure for a certain flow rate.
medale14
TL;DR Summary
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.

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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.

## 1. How is velocity of gas pump measured?

The velocity of gas pump is typically measured in units of distance per time, such as meters per second or miles per hour. This can be calculated by dividing the volume of gas pumped into the car tank by the time it takes to pump.

## 2. What factors affect the velocity of gas pump?

The velocity of gas pump can be affected by a variety of factors, including the type of fuel being pumped, the size and design of the pump nozzle, and the pressure and flow rate of the gas in the pump.

## 3. How can I calculate the velocity of gas pump for my specific car?

To calculate the velocity of gas pump for your specific car, you will need to know the volume of your car's gas tank and the time it takes to fill it. Then, divide the tank volume by the filling time to determine the average velocity of the gas pump for your car.

## 4. Can the velocity of gas pump vary?

Yes, the velocity of gas pump can vary depending on the factors mentioned above. It can also vary from one gas station to another, as different pumps may have different designs and capabilities.

## 5. Why is it important to know the velocity of gas pump?

Knowing the velocity of gas pump can help you estimate how long it will take to fill your car's gas tank and plan your time accordingly. It can also be useful for tracking your car's fuel efficiency and identifying any potential issues with the gas pump or your car's fuel system.

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