SR_4
Function SR_4(a, b, k) returns the thermal resistance between the surface of a rectangular contact area that is exposed to a uniform heat flux and is located on the surface of a semi-infinite half-space. The resistance is based on the temperature at the center of the rectangle (SR_5 provides the resistance based on the center temperature).
The calling protocol is:
R = SR_4(a, b, k)
Inputs:
a = half-width of the larger dimension of the rectangle [m or ft]
b = half-width of the smaller dimension of the rectangle [m or ft]
k = thermal conductivity of the material [W/m-K or Btu/hr-ft-R]
Outputs:
R = resistance [K/W or R-hr/Btu]
Rohsenow, W.M, J. P. Hartnett, and Y. I. Cho, Handbook of Heat Transfer, 3rd Edition, McGraw Hill, (1998).
Example:
$UnitSystem SI Mass J K Pa Radian
$VarInfo R4 units=K/W
a=1 [m]
b=1 [m]
k=1 [W/m-K]
R4=sr_4(a,b,k)
{Solution:
R4=0.2805 [K/W]}