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thshen34
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Homework Statement
Consider a steady flow of liquid with a density of 805 kg/m3 through a rotating tube as shown in the sketch. The flow speed is V = 5 m/s. If ω = 10 rad/s, find the torque necessary to rotate the pipe. Assume a uniform velocity distribution at the exit from the pipe, and that the
incoming fluid has no angular momentum.
Homework Equations
Conversation of momentum and Rotational Forces
The Attempt at a Solution
So I calculated the force of the fluid on the pipe, which is ρV(∏D^4)/4, which can be split up to y and x components, by multiplying cosθ and sinθ, respectively. However, this does not create any moment about the axis of rotation. So, my guess is that the x component of the force provides the centripetal force of the ω rotation. Given that F = mv^2/r, I'm thinking that the we can find the torque by Fr = mv^2, since we know v. Now, can someone help me find out what m ought to be? Is it just the mass of the bent pipe portion?
I think this is a valid attempt a solution, I only need a bit of concept cleared up. I hope someone will review this question please.
Thanks,
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