How can I create a constant flow? (not sure where to post)

In summary, the group is working on a STEM project to create a timer without using chemical reactions or electricity. One idea is to use a constant flow of water for a certain amount of time and measure the amount of water that comes out. They have considered various designs, including a water clock, a pendulum clock, and a container with an outlet pipe for a regulated outflow. The group plans to use red solo cups and graduated cylinders for their project.
  • #1
Parker Hame
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TL;DR Summary
I am doing a STEM project where we need to make a timer without any chemical reactions or electricity, and I think the best way to do this is to create a constant flow for a certain amount of time and weigh how much water comes out. What is the best way to create a constant flow of water for 10-300 seconds?
I am doing a STEM project where we need to make a timer without any chemical reactions or electricity, and I think the best way to do this is to create a constant flow for a certain amount of time and weigh how much water comes out. What is the best way to create a constant flow of water for 10-300 seconds?
 
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  • #2
Fun project. What are your thoughts so far?

I can think of one way to do it fairly accurately...
 
  • #3
Google "water clock" there is an ancient and venerable tradition of designing clocks that use water. There are dozens and dozens of basic designs.
 
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  • #4
anorlunda said:
Google "water clock" there is an ancient and venerable tradition of designing clocks that use water. There are dozens and dozens of basic designs.
The hard part about those is that I have no idea what the angle needs to be for it to work properly, or where to get a hollow cone.
 
  • #5
berkeman said:
Fun project. What are your thoughts so far?

I can think of one way to do it fairly accurately...
I’m thinking maybe using a throttle type device and two tanks of water
 
  • #6
Parker Hame said:
The hard part about those is that I have no idea what the angle needs to be for it to work properly, or where to get a hollow cone.
The cone was only one of many. Here's a simpler one.

1570827232084.png


And another.
1570827384201.png
 
  • #7
Did anyone suggest a pendulum clock?
A saw blade (hacksaw) could be lowered tooth by tooth by an escapement attached to a fixed length pendulum, that repeats a cycle every second. The blade will fall out when the number of teeth initially engaged have passed down through the escapement. You would need a blade with over 300 teeth for 1 second accuracy.
 
  • #8
Baluncore said:
Did anyone suggest a pendulum clock?
Yes, a pendulum clock powered by a water wheel instead of a weight on a string.
 
  • #9
Does it have to be water.
Other options.
An egg timer perhaps.
https://en.wikipedia.org/wiki/Hourglass
If water, one could set the faucet to drip, drip, drip, and do counting instead of weighing.
 
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  • #10
Parker Hame said:
What is the best way to create a constant flow of water for 10-300 seconds?

One thought is to have a container where inflowing water at the top of the continer keeps it overflowing, so the water level is in the container is approximately constant. Near the bottom of the container, have an outlet pipe whose outflow is much less than the inflow at the top. The outflow would be driven by an approximately constant pressure.
 
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  • #11
Stephen Tashi said:
One thought is to have a container where inflowing water at the top of the continer keeps it overflowing, so the water level is in the container is approximately constant. Near the bottom of the container, have an outlet pipe whose outflow is much less than the inflow at the top. The outflow would be driven by an approximately constant pressure.
This idea sounds great! I think this is what we will do, red solo cups and graduated cylinders to the rescue!
 
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  • #12
Stephen Tashi said:
Near the bottom of the container, have an outlet pipe whose outflow is much less than the inflow at the top.
The overflow only has to remain positive, it does not need to exceed the regulated outflow.
The reservoir could have a large surface area of water to reduce sensitivity to flow regulation.
 

1. How can I create a constant flow using gravity?

The simplest way to create a constant flow using gravity is to set up a siphon. This involves filling a tube with liquid, placing one end in a container of liquid at a higher elevation, and placing the other end in a container at a lower elevation. The liquid will flow from the higher container to the lower one, creating a constant flow. Make sure the end of the tube in the lower container is below the surface of the liquid to maintain the flow.

2. Can I use a pump to create a constant flow?

Yes, a pump can be used to create a constant flow. The type of pump needed will depend on the specific application. Centrifugal pumps are commonly used for creating a constant flow of liquid, while positive displacement pumps are better for creating a constant flow of gas. It is important to properly size and maintain the pump to ensure a consistent flow.

3. How can I regulate the flow rate?

The flow rate can be regulated by adjusting the size of the opening or diameter of the tube through which the liquid or gas is flowing. This will affect the pressure and velocity of the flow. Additionally, using a valve or flow regulator can help control the flow rate. It is important to carefully monitor and adjust the flow rate to maintain a constant flow.

4. Is it possible to create a constant flow without using gravity or a pump?

Yes, it is possible to create a constant flow without using gravity or a pump. This can be achieved through the use of pressure differentials, such as in a water tower or pressurized tank system. The pressure differential will cause the liquid or gas to flow from an area of higher pressure to an area of lower pressure, creating a constant flow.

5. What factors can affect the creation of a constant flow?

There are several factors that can affect the creation of a constant flow, including the type of fluid being used, the size and shape of the container or tubing, the pressure and velocity of the flow, and any external influences such as temperature or air resistance. It is important to consider and monitor these factors to ensure a consistent and reliable flow.

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