fix typos

uni/mmme/2047_thermodynamics_and_fluid_dynamics/dimensional_analysis.md

@@ -175,7 +175,7 @@ When $\text{Ma} > 0.3$, the flow should be considered compressible.
 
 # Nondimensional Momentum Equation (From Navier-Stokes)
 
-$$\frac{\del \pmb{V*}}{\del t*} + \pmb{V*} \cdot (\Del* \pmb{V*} = -\Del* p* + \frac{1}{\text{Re}}\Del*^2\pmb{V*}$$
+$$\frac{\delta \pmb{V^*}}{\delta t^*} + \pmb{V^*} \cdot (\nabla^* \pmb{V^*}) = -\nabla^* p^* + \frac{1}{\text{Re}}\nabla^{*2}\pmb{V^*}$$
 
 Therefore for large values of Reynolds number, the viscous forces become negligible.
 
@@ -185,7 +185,7 @@ An airfoil model and prototype are geometrically similar, with $1:\alpha$ length
 
 - $x_m = \frac{x_p}{\alpha}$, $y_m = \frac{y_p}{\alpha}$
 - $u_m$ at $(x_m, y_m)$ must have the same direction at $u_p$ at $(x_p, y_p)$
-- $\frac{u_p}{u_m} = \Beta$ is constant at homologous points
+- $\frac{u_p}{u_m} = \beta$ is constant at homologous points
 
 ![](./images/vimscrot-2023-02-06T09:46:38,665212789+00:00.png)