ET,matid,FLUID116
KEYOPT,matid,1,1                         ! TEMP degree of freedom only
KEYOPT,matid,2,1                         ! Convection passed to SURF151 /SURf152

RADIUS = 12.5e-3
PERIMETER = 2*3.14159*RADIUS
FLOW_SECTION = 3.14159*RADIUS*RADIUS
HYDRAULIC_DIAMETER = 4*FLOW_SECTION / PERIMETER
R,matid,HYDRAULIC_DIAMETER, FLOW_SECTION,1 
