Institute of Problems of Mechanical Engineering

Eigenvalue Falls in Thin Broken Quantum Strips

Abstract. We are interested in the spectrum of the Dirichlet Laplacian in thin broken strips with angle [Formula: see text]. Playing with symmetries, this leads us to investigate spectral problems for the Laplace operator with mixed boundary conditions in trapezoids of thickness...

Relatively Undistorted Solutions to the Wave Equation: A Review

A review of simple solutions to the linear wave equation in three spatial variables, involving arbitrary functions, is given. Physicists’ interest in these solutions is primarily motivated by the need for a convenient description of spatiotemporally localized wave beams and packe...

Artificial-Lift System Control: A Reduced-Order Transient Model for Real-Time Predictive Control of Electrical Submersible Pump Wells

Unstable well operations, driven by reservoir depletion, high gas–oil ratios, unstable inflow, and surface network interactions, have become a major challenge in modern production — especially in Western Siberian fields — causing flow instabilities and production losses. While nu...