add exercise sheets, lecture notes, lecture slides

uni/mmme/2044_design_manufacture_and_project/bearings.md

@@ -4,12 +4,28 @@ date: \today
 title: MMME2044 // Bearings
 tags: [ bearings ]
 uuid: 94cac3fd-c352-4fdd-833d-6129cb484b8a
-lecture_slides: [ ./lecture_slides/Lecture 7 - Bearings 1 – Plain Hydrodynamic Bearings 1.pdf ]
+lecture_slides: [ ./lecture_slides/Lecture 7 - Bearings 1 – Plain Hydrodynamic Bearings 1.pdf, ./lecture_slides/Lecture 11 - Bearings 2 - Rolling Element Bearings.pdf ]
 anki_deck_tags: [ bearings ]
 ---
 
 > I don't think I ever finished these notes.
 
+# Errata
+
+## Lecture Slides 2 (Lecture 11), slide 18
+
+Static load carrying capacity equation is
+
+$$S_0 = \frac{P_0}{C_0}$$
+
+but should be:
+
+$$S_0 = \frac{C_0}{P_0}$$
+
+If the load applied to a bearing is half of its rated capacity,
+then you have a safety factor of 2.
+Therefore the equation in the slides must be incorrect.
+
 # Types of Bearings
 
 <details>

uni/mmme/2047_thermodynamics_and_fluid_dynamics/heat_transfer.md

@@ -72,11 +72,12 @@ Nusselt number is a dimensionless number:
 $$\text{Nu} = \frac{hL}{k_f}$$
 
 where $k_f$ is conductivity of the fluid, $L$ is the representative length (e.g. diameter, length,
-internal width, etc.).
+internal width, etc.), and $h$ is heat transfer coefficient.
 
 Since $h$ is unknown a lot of the time, sometimes Nusselt number must be found through approximating
 by other dimensionless numbers: Prandtl, Reynolds, and Grashof.
 
+
 Nusselt number for a laminar forced flow is around 3.66.
 For a turbulent forced flow it is estimated to be: