Resistance evaluation for flying boats sliding at medium and high speed in calm water

Considering the unique multimedia condition during take-off process of a flying boat and referring to the method of studying the resistance performance of a planning boat in the sliding process,a formula,to evaluate the resistance of a flying boat at medium and high speed in calm water,was proposed. The formula combines theoretical analysis and empirical correction and also includes the effect of aerodynamic distribution.With this formula,graphs illustrating hydrodynamic resistance and pitch angle varying with the volume Froude number were obtained and the reasons for the varying were analyzed. Take-off running distance was calculated with the hydrodynamic resistance and pitch angle that calculated from the formula. As the calculated take-off running distance is in consistent with experimental results,the validation of the formula was verified indirectly. And a method to calculate the take-off running distance of a flying boat was also proposed at the same time.