ISSN Online: 2377-424X
ISBN Print: 978-1-56700-421-2
International Heat Transfer Conference 15
Experimental Study on Heat Transfer Characteristics of High-Velocity Circular Jet Impingement Boiling on the Nano-characteristic Stagnation Zone
Abstrakt
The jet impingement boiling is the most effective heat transfer method among all the steady-state heat
transfer forms. So far, various researches on the jet impingement boiling still lack experimental data under
high impact velocity and special heated surface topography. Due to this reason, the present experimental
study investigates the heat transfer characteristics of high-velocity circular jet impingement boiling on the
nano-characteristic stagnation zone with different wettability. The surface wettability is varied to hydrophilic or hydrophobic nano-characteristic surfaces by modifying surface topography and chemistry. The effects of
impact velocity, subcooling and solid-liquid contact angle (CA) on the onset of nucleate boiling (ONB),
nucleate boiling heat transfer coefficient (HTC) are studied experimentally. It is found that their effects on
the ONB are respectively independent. Wherein, the impact velocity and the subcooling are respectively in
positive relationship with the wall superheat corresponding to the ONB point, while CA is in linear inverse
relationship with it. Comprehensive effects of impact velocity and CA on the nucleate boiling HTC are also
obtained. The proportion of nucleate boiling HTC after the ONB point gets more significant with increasing
wall superheat. The HTC will increase with the impact velocity and CA. Some correlations are proposed for
predicting the various effects on the jet boiling heat transfer characteristics. The comparison results indicate
the predicted value agrees well with the experimental data.