A parametric study of nucleate boiling on structured surfaces, part II: Effect of pore diameter and pore pitch

This two-part experimental work identifies the effect of geometric dimensions on the boiling performance of "tunneled" enhanced boiling surfaces, which is similar to the Hitachi Thermoexcel-E surface. Tests were performed an a horizontal tube using R-Il and R-123 at 26.7 degrees C for heat fluxes from 2 to 70 kW/m(2). This second part of the study defines the effect of the pore dimensions (pore diameter and pore pitch). The pore diameters are 0.12, 0.18, 0.23, and 0.28 mm and the pore pitches are 0.75, 1.5, and 3.0 mm. The results are interpreted to explain the relationship between pore diameter and pore pitch on the boiling performance.