Hey guys, I'm trying to learn fluid mechanics while at an internship and i just have a quick question. Let's say i have a fluid flowing down and incline plane with a quadratic velocity profile. Which direction does the shear stress (tau) act?(adsbygoogle = window.adsbygoogle || []).push({});

I know the formula for shear stress is tau = mu*(du/dy) where u is the velocity profile and mu is the viscosity. In the problem im working on, the derivative of the velocity profile (du/dy) points down the incline, does that mean shear stress also points down the incline?

the reason i ask such a basic question is that the hint on the problem says the shear stress must counteract the parallel weight of the fluid. the weight points down the slope so this is saying the shear stress points up the slope, but the formula above is saying it also points down the slope

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# Basic fluid mechanics question

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