Correct Answer - Option 2 : Viscous force
Explanation:
Reynolds number:
It is a dimensionless number which helps to predict flow patterns in different fluid flow situations. At low Reynolds numbers, flows tend to be dominated by laminar flow, while at high Reynolds numbers flows tend to be turbulent.
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Number
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Definition
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Significance
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Reynolds No
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\(Re = \frac{{Inertia\;Force}}{{Viscous\;Force}} \Rightarrow \frac{{\rho VL}}{\mu }\)
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Flow in closed conduit i.e. flow through pipes.
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Froude No
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\(Fr = \sqrt {\frac{{Inertia\;Force}}{{Gravity\;Force}}} \Rightarrow \frac{V}{{\sqrt {gL} }}\)
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Where a free surface is present and gravity force is predominant.
Spillway, Open Channels, waves in the ocean.
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Euler No.
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\({E_u} = \sqrt {\frac{{Inertia\;Force}}{{Pressure\;Force}}} \Rightarrow \frac{V}{{\sqrt {\frac{p}{\rho }} }}\)
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In cavitation studies, where pressure force is predominant.
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Mach No.
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\(M = \sqrt {\frac{{Inertia\;Force}}{{Elastic\;Force}}} \Rightarrow \frac{V}{C}\)
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Where fluid compressibility is important.
Launching of rockets, airplanes and projectile moving at supersonic speed.
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Weber No.
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\({W_e} = \sqrt {\frac{{Inertia\;Force}}{{Surface\;tension\;Force}}} \Rightarrow \frac{V}{{\sqrt {\frac{\sigma }{{\rho L}}} }}\)
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useful in analyzing fluid flows where there is an interface between two different fluids, especially for multiphase flows with strongly curved surfaces. |
