If I have a stream of moving fluid (moving at a velocity of $v$) flowing past a plate, is there a formula that calculates the pressure exerted by the fluid as a result of the movement of the fluid? More specifically, what is the difference in pressure if the fluid is static and moving?
I found a concept called dynamic pressure – but it doesn't seem to fit in this situation. By Bernoulli's principle, the faster the fluid the lower the pressure should be, but dynamic pressure was given as $q\propto v^2$, which is the opposite of what Bernoulli's principle states.
So my question is, is there a formula (as a function of $v$) for the pressure exerted specifically by the motion of a fluid on an object?
Best Answer
Bernoulli's principle states that the following expression is a constant $$\frac{1}{2}\rho v^2 + \rho g z + p = \mathrm{const}$$ From this equation you can evaluate the pressure reduction of a moving fluid.
Example: If you know the pressure $p_0$ of the fluid at rest and assuming there is no hight difference, $z=\mathrm{const}$ you get $$p_0 = \frac{1}{2}\rho v^2 + p$$ or $$p = p_0 - \frac{1}{2}\rho v^2$$