Embedded Isothermal Flat Plate
Calculates the shape factor S and heat transfer rate Q for a flat plate of width W and length L (where W>L) buried at depth d in a semi-infinite medium of conductivity k, below an isothermal surface.
The governing relationship is:
Q=S⋅k⋅(Tp−Ti)where Tp is the plate temperature and Ti is the surface temperature.
Shape Factor Cases
Case 1 — Plate at the surface (d=0, W>L):
S=ln(4W/L)πWCase 2 — Deeply buried wide plate (d≥10W, W>L):
S=ln(4W/L)2πWCase 3 — Very wide plate at moderate depth (W≥10L, d≥2W):
S=ln(2πd/L)2πWThermal Resistance
R=k⋅S1[K/W]Reference
Holman, J. P., Heat Transfer, 7th ed., McGraw-Hill, 1990, pp. 74–83.