Study on Heat Transfer Correlations for the Closed-loop Airborne Spray Cooling System With R22 as the Cooling Medium

A closed-loop experimental bench for airborne application with R22 as the cooling medium was established and heat transfer characteristics on the heating surface in the boiling region and the failure region were investigated, which provide reference for the design of thermal management system for airborne weapon with high heat ux. Four dimensionless parameters were defined, which were Renolds numberRe, Weber number We, Jacob number Jaand dimensionless temperature". And then the heat transfer correlations for boiling region spray cooling and failure region spray cooling were obtained. The deviations between the experimental values and the fitting values are all within ±15% which satisfy the requirements of engineering design in aircraft. From the fitting process it can be deduced that in the boiling region the Weber number We could not be ignored. Compared with the dimensionless temperature ε, Jacob number Ja is preferred to reflect the temperature variation tendency of the droplets and the heating surface during the boiling heat transfer process. During the failure state the most significant heat transfer parameter is Weber number We.