Metal Foams: A Design Guide

246 Appendix: Catalogue of material indices
(g) (continued)
Function and constraints Maximize a
HEAT SINKS
Maximum heat flux per unit volume; expansion limited /1˛
Maximum heat flux per unit mass; expansion limited
HEAT EXCHANGERS (pressure-limited)
/ 1˛
Maximum heat flux per unit area; no failure under 1p f
Maximum heat flux per unit mass; no failure under 1p f/
a D thermal conductivity; a D thermal diffusivity; Cp D specific heat capacity; Cm D material cost / kg; Tmax D maximum
service temperature; ˛ D thermal expansion coeff; E D Young’s modulus; D density; f D failure strength (the yield strength
for metals and ductile polymers, the tensile strength for ceramics, glass and brittle polymers).