화학공학소재연구정보센터
International Journal of Heat and Mass Transfer, Vol.46, No.20, 3897-3907, 2003
Bubble nucleation on micro line heaters under steady or finite pulse of voltage input
Nucleation temperatures on micro line heaters under steady voltage input were measured precisely by obtaining the I-R (current-resistance) characteristic curves of the heaters having dimensions of 50 mum in length, 3 or 5 mum in width, and 0.583 mum in thickness. The bubble nucleation temperature on the heater with 3 mum width is higher than the superheat limit, while the temperature on the heater with broader width of 5 mum is considerably less than the superheat limit. The nucleation temperature under a finite voltage pulse input was also measured for 5-mum width heater. The nucleation temperatures were also estimated by using the molecular cluster model for bubble nucleation on the cavity free surface with effect of contact angle. The bubble nucleation process was observed by a microscope/35 mm camera unit with a flash light of mus duration. (C) 2003 Elsevier Science Ltd. All rights reserved.