During rapid expansion in supersonic nozzles and turbine blades, under special conditions, steam may become supercooled vaporand the heat release rate - - due to phase change is substantial. Droplet radius -r- and Wetness fraction -WF-are important parameters in design of wet steam equipment. Until now, cost-intensive and complicated methods are applied for designing wet steam equipment. In this paper an innovative method based on Buckingham-pi dimensional analysis is proposed for predicting r andWFusing dry vapor data only. A dimensionless droplet radius -DDR- is obtained from the influential parameters at Wilson point -named DWP-. First, DWP, DDR and WF are obtained from the results of the analytical modeling, then two regression equations are proposed for calculating DDR and WF with DWP. Finally, results of the proposed regression relationships are compared for 7 analytical cases and the average percent errors associated with the presented equations for the droplet radius or DDR andWF percentage - - found to be less than 30% and12%,respectively.

Keywords