In this paper,a rotational supercavitating evaporator(RSCE)was at first modeled by means of theoretical analysis approach.The geometrical characteristics of supercavity in the modeled RSCE were then studied through numerical simulations.The current research objectives consist in determination of shape of the supercavitator(which in the plane of rotation generates supercavity occupying the most volume between blades),and location of the area suitable for steam extraction by revealing the inner structure of supercavity.Analytical analysis was performed by solving empirical equations for the shape of RSCE,through which an evaluation of two-dimensional relative position of supercavity trailing edge for different shapes of the supercavitator has been realized.Numerical simulation was then carried out,by numerically solving the unsteady Navier-Stokes equations in their conservation form coupled with the Rayleigh-Plesset cavitation and Shear-Stress Transport turbulence models,for verification of the results obtained from empirical equations.Despite unreliable assumption of applicability of empirical equations we have confirmed similarity of the supercavity shapes obtained by both methods for the same RSCE.Therefore,the shape of supercavitator calculated by using empirical equations is acceptable,which provides a simple but reliable approach for design of RSCE.The inner structure of supercavity obtained by numerical simulation has indicated position and parameters for steam extraction openings for further numerical and experimental studies on the performance of RSCE.Practical application of steam or gas extraction is suggested for solving of some problems associated with cavitating pumping of cryogenic liquid. In this paper, a rotational supercavitating evaporator (RSCE) was at first modeled by means of theoretical analysis approach. The geometrical characteristics of supercavity in the modeled RSCE were then studied through numerical simulations. The current research objectives consists in determination of shape of the supercavitator which in the plane of rotation generates supercavity occupying the most volume between blades, and location of the area suitable for steam extraction by revealing the inner structure of supercavity. An analytical analysis was performed by solving empirical equations for the shape of RSCE, through which an evaluation of two-dimensional relative position of supercavity trailing edge for different shapes of the supercavitator has been realized. Numerical simulation was then carried out, by numerically solving the unsteady Navier-Stokes equations in their conservation form coupled with the Rayleigh-Plesset cavitation and Shear-Stress Transport turbulence models, for verification of the results obtained from empirical equations we have confirmed similarity of the supercavity shapes obtained by both methods for the same RSCE.Therefore, the shape of supercavitator calculated by using empirical equations is acceptable, which provides a simple but reliable approach for design of RSCE. inner structure of supercavity obtained by numerical simulation has indicated position and parameters for steam extraction openings for further numerical and experimental studies on the performance of RSCE. Practical application of steam or gas extraction is suggested for solving of some problems associated with cavitating pumping of cryogenic liquid.