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Questions tagged [flow-control]

The act of regulating the rate of fluid movement through flow conduits, or into and out of fluid containing vessels. Control action may or may not involve sensing of the flow rate and feedback of flow measurement, but in all cases involves some means of throttling the flow in either an on-off or proportional manner.

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What is the purpose of these "steps" in rivers?

I have seen a number of structures within rivers, which resemble steps, and which allow the water to cascade down them instead of flowing naturally down the course of the river. Example 1: River Avon in Bath Example 2: River Seine in Paris (from…
March Ho
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Best way to get rid of turbulent flows?

I am making a testing facility for pumps. This facility has to be able to handle 500 m3/h with at little turbulence as possible. The basin itself is 5 meters long, 2,5 meters wide and 2 meters tall. The water level in the basin is kept at 1,9…
Arjo
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Buoyancy force problem

I'm trying to design a kind of water valve with inexpensive materials as a first prototype. The water flow from the PVC pipe (1) reach the body of the valve and pass through an aluminum grid (3) to the water tank. When the water level goes up…
Joaquin Osses
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Could a water stream be used as a fiber optic sensor and detect when the stream is broken?

I have a small idea/project I am working on in which I want to use a water fiber optic sensor that can detect whether the water stream is broken and if so shut off the water. Having looked into fiber optic sensor systems in general, all I have…
James Dawson
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Given flow rate of an orifice at one pressure, how do I calculate flow rate for a different pressure?

Given an orifice rated 1.8 GPM of water at 90 PSI, how do I calculate the flow rate at 30 PSI and what rating I would need to purchase to achieve 1.8 GPM at 30 PSI? Below added to give some context, based on responses. Sorry, as a programmer I…
Pascal
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Ideal funnel design for powders

I'm designing a funnel/bottle for a powder. My goal is to have all of the bottle's powder contents come out when inverted. However, the powder has a tendency to stick to itself (like flour or brown sugar) and so I will run into a chance that the…
Davbog
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Consistent Fluid or powder flow through an orifice

This is a really odd and specific question, and I'm not sure this is even where to ask. A few weeks ago I thought about making a clock based on water flowing from an orifice. The obvious issue is that the flow rate would vary significantly based on…
Austin Fox
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Transfer of low density solids

Which sort of equipment is specifically designed for flowing/pumping low density solids (powders) e.g. for loading from a drum to a receiver?
Beerhunter
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How can I ensure steady flow to all the valves?

I've set this up for my hydroponics water distribution system. The water is pumped up, and is distributed via the valves. I can manual control the valves so that each outlet has a steady flow of water. However, the pump is on a timer and when it…
Methos
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When NOT to use Bessel's Correction for Standard Deviation

I can not find a clear explanation for when NOT to use Bessel's correction and use N instead of N-1. As I understand it, Bessel's correction would apply to things such as clinical trials, sampling from a production line, voter polling, etc. I am…
Justin
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Do pressure regulators restrict the mass flow rate?

Suppose we have a tank containing compressed air. If a hole is made in the tank the air will start flowing out. The mass flow rate of exiting air will be heavily dependent on the diameter of the orifice (ie the narrowest opening on the system) -…
Izak the coder
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Can ultrasonic sound pass through solid medium?

For my electronic project, I have been searching the internet for a non invasive flow meter that does not require disassembly. I have found an ultrasonic measurement technique that use the clamp on method (just fitting on to the pipe) for flow…
Taha
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What specific characteristic of proportional solenoid valves makes the flow to current behavior quadratic?

If experimental data is obtained from a proportional solenoid valve, specifically flow vs current (assuming inlet pressure is constant), the fit is nearly quadratic in nature. Andersen's Analysis and Design of Pneumatic Systems predict that the flow…
docscience
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A 40L compressed air cylinder at 100 bar is emptied in pulses at the rate of 41kg/s. How many such cycles would it take to empty the cylinder?

I am constructing a blowback gas system where clogged debris needs to be removed with compressed air using compressed air cylinder. 40L compressed air cylinder at 100bar pressure is available as standard here. The pressure has to be relieved at the…
Yadunandan
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Why do Ejectors have a Venturi/Contraction?

Ejectors are flow devices that provide low back-pressure to a duct by passing a gas jet past the duct and taking advantage of the low pressure region this creates (See figure). A common usage of this device is for paint spray guns. I outlined the…
A McKelvy
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