From 83cd3ad5859bf387d0b54a84ff10c64a505d2769 Mon Sep 17 00:00:00 2001
From: Alvie Rahman <alvierahman90@gmail.com>
Date: Tue, 31 Jan 2023 21:48:07 +0000
Subject: [PATCH] add standard nondimensional groups in fluids

---
 .../dimensional_analysis.md                   | 40 +++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/uni/mmme/2xxx/2047_thermodynamics_and_fluid_dynamics/dimensional_analysis.md b/uni/mmme/2xxx/2047_thermodynamics_and_fluid_dynamics/dimensional_analysis.md
index e173dd9..abda66c 100755
--- a/uni/mmme/2xxx/2047_thermodynamics_and_fluid_dynamics/dimensional_analysis.md
+++ b/uni/mmme/2xxx/2047_thermodynamics_and_fluid_dynamics/dimensional_analysis.md
@@ -120,4 +120,44 @@ where $M$, $L$, and $T$ are units of mass, length, and time respectively.
 The two equations results in some simple simultaneous equations to solve to find the
 coefficients $a$, $b$, $c$, $d$, $e$, $f$.
 
+# Standard Nondimensional Groups in Fluids
+
+This is not an exhaustive list.
+
+## Reynolds Number
+
+$$\text{Re} = \frac{\rho U L}{\mu}$$
+
+Represents ratio of intertial forces over viscous forces.
+Important in all viscous flows.
+
+## Froude Number
+
+$$\text{Fr} = \frac{U^2}{gL}$$
+
+Represents ratio of inerital forces over gravitational forces.
+Important in flows with interfaces (e.g. gas-liquid).
+
+## Weber Number
+
+$$\text{We} = \frac{rho U^2 L}{\sigma}$$
+
+where $\sigma$ is the surface tension coeffecient.
+
+Represents ratio of inertial to capillary forces.
+Important to flows with strong surface tension effects (e.g. droplets,
+bubbles, jets)
+
+## Strouhal Number
+
+$$\text{St} = \frac{fL}{U}$$
+
+where $f$ is frequency.
+
+Important in flows with velocity oscillations.
+
+## Mach Number
+
+$$\text{Ma} = \frac U a$$
+