Development and computational analysis of a wave hydrodiode with a flow path profile based on cubic splines

   The article introduces a wave hydrodiode — a passive hydraulic device in which periodic variation of the half-gap along the channel creates a difference in hydraulic resistance between forward and reverse flow directions. The profile of the flow section is defined by a cubic spline. The geometry is fully determined by three independent parameters: the minimum half-gap, the half-gap at the splice point, and the relative coordinate of the splice point. Numerical simulation is performed using Computational Fluid Dynamics methods based on steady-state Reynolds-averaged Navier–Stokes equations and the k–ω turbulence model. Differential-geometric analysis has shown that the zero fourth derivative of the cubic spline within each polynomial segment limits the reproduction of sharp curvature discontinuities necessary for effective vortex-based flow blocking. The obtained results demonstrate that spline parameterization is effective for smooth profiles, reducing the number of variable parameters, but requires replacement with discrete models for geometries with local edge aggressiveness. The findings lay the groundwork for multi-criteria topological optimization of passive shut-off devices for nuclear reactors.

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