(V08CT09A034)EFFECTS OF SURFACE ROUGHNESS AND INCLINATION ANGLE ON NUCLEATE BOILING OF PF-5060 DIELECTRIC LIQUID ON COPPER

摘要

Saturation pool boiling experiments of PF-5060 dielectric liquid are performed using eleven different Cu surfaces with . average roughness, Ra = 0.21 to 1.79 urn, at inclination angle, 8, from 0° (upward facing) to 180° (downward facing). Nucleate boiling heat transfer coefficient, h_(NB), increases with increasing surface roughness and with decreasing inclination angle. The measured enhancements in h_(NB) with increased surface roughness are in excess of 36%. In the upward facing orientation, the experimental values of h_(NB) are correlated in terms of the surface heat flux in the experiments, q, as: h_(NB) = A q~B. The coefficient "A" increases from -0.14 to 0.23, while the exponent "B" decreases from 0.76 to 0.69 as Ra increases from 0.21 to 1.79 urn.