How to calculate the velocity reduction in pipes

[Vinodhkumar]

I have a big pipe with known diameter, length and velcity at big pipe. There are two pipes dividing form the big pipe with varing diameter and length.
1) How to calculate velocity of water in these two pipes?
2) If I add one more pipe of known length and diameter, what would be the velocity in each of these pipes.

Many Thanks...

 

[mfb]

You need the pressure at every entry/exit point of your pipe system. Each pipe has a specific relation "flow for specific pressure difference" (where the dependency on the absolute pressure should be small), this depends on the geometry.

 

[Vinodhkumar]

Yes, I have pressure value for the pipes. But, it is same for all over the pipe. I won't be able to measure at each entry and exit of the pipes :(

 

[mfb]

If the pressure is the same everywhere, you cannot get any flow, unless the system has zero friction (in this case, the flow cannot be calculated without knowledge about the remaining system).

 

[PJC01]

I would first like to clarify that the velocity of water in pipes can be calculated using various equations, such as the Bernoulli's equation or the continuity equation. The specific equation to use would depend on the specific conditions and assumptions of the system.

1) To calculate the velocity of water in the two pipes dividing from the big pipe, you would need to know the flow rate of water entering the big pipe, as well as the diameter and length of the two smaller pipes. Using the continuity equation, which states that the flow rate is constant throughout a closed system, you can calculate the velocity in each of the smaller pipes. This equation is given by Q = Av, where Q is the flow rate, A is the cross-sectional area of the pipe, and v is the velocity.

2) Adding one more pipe of known length and diameter to the system would affect the flow rate and velocity of water in the entire system. To calculate the new velocity in each pipe, you would need to recalculate the flow rate using the updated system parameters and then use the continuity equation again to calculate the velocity in each pipe. It is important to note that adding another pipe would also introduce friction and other factors that could affect the velocity of water in the system.

In conclusion, calculating the velocity reduction in pipes is a complex process that requires knowledge of the system parameters and the use of appropriate equations. It is important to carefully consider all factors and assumptions when making these calculations in order to obtain accurate results.