Problem calculating liquid flow rate?
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Hello everyone, I would like to ask the following question: There are two points, A and B, which are 10 meters apart from each other. A pipe with a diameter of 108 runs between these two points. Point A is at a height of 7 meters, while point B is at a height of 10 meters. Now, a liquid with a density of 1200 kilograms per cubic meter and a flow rate of 20 cubic meters per hour flows from point B to point A. What is the flow velocity of the liquid inside the pipe? Can it be calculated?
For a continuous and steady flow, the flow rate is independent of the distance and height between points A and B, as well as of the density of the material. The formula for calculating the flow rate in the tube is: 20/3600 ÷ (108×0.7854×d×d), where d is the diameter of the tube. Since this value is missing, it is not possible to calculate the flow rate in the tube; the flow rate can be determined once this value is available.
It can be calculated using Bernoulli’s equation and mass balance
Reply to 1# Haneguri’s Stone: The inner diameter of the 108 pipe is 100 mm, or 0.1 m. Converting the flow rate to per second gives: 20/36000. Formula: v = (3.14/4) × d²u. Therefore, u = 4 × 20 / (3600 × 3.14 × 0.1²) = 0.71 (m/s)
Reply to 2# chinazwr: What do you mean by \"tube bundle\"? Does it count if it flows through this 108 tube?
Reply to 4# phlpf2009: Hello, that can’t be right. Is the flow rate not related to the height difference between A and B?
Reply to 2# chinazwr: There are no listed pipes; there’s just one pipe. How should this be calculated?
Reply to #6: Yuuri’s Stone. The flow velocity is related to the height difference, but you’ve already provided the flow rate here.
Reply to 8# phlpf2009: What is the relationship between height and flow rate?
This post was last edited by phlpf2009 on 2011-1-31 at 10:35. Reply to #9: For the formula gh=λ(L/d)(u²/2), we still need to know the friction coefficient λ in order to perform the calculation. g: acceleration due to gravity, 9.81 m/s2; h: height difference of the pipeline, in meters ； λ: Coefficient of friction ； No unit ； L: Pipe length ； m d: pipe diameter ； m u: Flow velocity, m/s ；
Reply to post #10 by phlpf2009: What do all the symbols in the formula represent? Could you explain that further?