Heat transfer characteristics in mist cooling with commercial machining oil were investigated experimentally. Steady state experiments of heat transfer were conducted using a pure copper cylinder and mist flow of commercial machining oil and air. Liquid flow rate was 0.3, 0.9, 1.8, 4 and 8 l/hr, respectively; each air flow rate was 0, 40, 75 and 120 lN/min. Furthermore, liquid mass flux on the heating surface for each experimental condition was measured by using a measuring cylinder with same diameter as the heater. Average velocity of droplets and average diameter of those were measured by using a laser doppler anemometer and immersion method, respectively. The heat transfer mechanism in oil mist was only cooling of liquid film formed on a heated surface, whereas the heat transfer mechanism in water mist cooling was classified into three regions. The heat transfer coefficient in the oil mist was well expressed by the heat removal capacity on sensible heat of supplying oil-droplets to the heated surface. Four dimensionless correlations were derived from a dimension analysis, Buckingham Pi theorem, and experimental data for both water mist and the oil mist.
Corrosion Detection of an Orifice Plate for Flow Rate Measurement using Heat Transfer Mechanism
