Area Thermal Expansion
Area Thermal Expansion
A heated plate expands in both directions, so its area grows at roughly twice the linear expansion rate.
The area change is ΔA = 2·α·A·ΔT. where α is the linear expansion coefficient, A the area and ΔT the temperature rise.
Inputs
alpha := 23e-6 K^-1=2.3e-05 1/K
A := 0.5 m^2=0.5 m^2
dT := 80 K=80 K
Apply the area-expansion formula.
dA := 2·alpha·A·dT=1.84e-03 m^2
Results
The factor of two comes from expansion in two directions. Volumetric expansion similarly uses a factor of three.
Assumptions & limitations
- Isotropic expansion.
- Small temperature change.
- Area coefficient ≈ 2× linear.