Heat Transfer Cheat Sheet
Table of Contents
This page provides an “equation sheet” that students like to use on tests. Developed by Vanderbilt University’s heat transfer class (ME 248, Fall)
Sign Convention
We are using Prof. Walker’s convention:
| name | quantity | units | alternative |
| heat tansfer | q | W | Q or ![]() |
| heat flux | q'' | W / m2 | q |
| generation | q''' | W / m3 | G |
Equivalent Resistance
Analogy of electricity to Fourier’s Law
Assumptions
- No generation
- Constant properties
- Steady state
- One-dimensional conduction
where
is the series and parallel combination of resistances as if they were resistors in units of K/W.
For Conduction:
Planar:
Cylindrical:
Spherical:
For Convection:
Planar:
Cylindrical:
Spherical:
For Radiation:
Or if
then
where
and
at the middle of two know temperatures
For Contact Surfaces:
Basic definitions: Heat transfer- thermal energy in transit due to a spatial temperature difference. Conduction- heat transfer across a medium (solid or fluid). Convection- heat transfer between a surface and a moving fluid. Thermal Radiation- all surfaces of finite temperature emit energy in the form of electromagnetic waves.
