Why is the flow rate in smooth pipes lower than that in rough pipes when distributing flow through pipes?
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RT, according to the formulas in the book, a smoother pipe with a lower friction coefficient should result in a higher flow rate
Both flow rate and friction coefficient are related to the pipe diameter
What if the light tube is thin, long, and has many bends?
The friction coefficient is just one factor; there are also factors such as equivalent length and elevation. Ultimately, the final flow rates of the two pipes should be determined by ensuring that their energy losses are equal
The diameter of the rough tube is no more than 5% larger than that of the smooth tube; both tubes have the same length. However, the flow rate through the smooth tube is only 0.8 times that of the rough tube. Of course, in reality both tubes are connected to sections of tubes that are neither smooth nor rough, but the conditions for these two sections are identical. If only the friction coefficient for these sections is considered (and in fact the Reynolds number also differs by less than one order of magnitude), the calculated friction coefficient turns out to be negative, which is clearly unreasonable
The diameter of the rough tube is no more than 5% larger than that of the smooth tube; both tubes have the same length. However, the flow rate through the smooth tube is only 0.8 times that of the rough tube. Of course, in reality both tubes are connected to sections of tubes that are neither smooth nor rough, but the conditions for these two sections are identical. If only the friction coefficient for these sections is considered (and in fact the Reynolds number also differs by less than one order of magnitude), the calculated friction coefficient turns out to be negative, which is clearly unreasonable
It may be related to the degree of laminar flow and turbulent flow.