arXiv subjects

Arseniy Parfenov

Publications and source records attributed to Arseniy Parfenov.

3 recordsLinked to original sources

arXiv2026

Gas-liquid stratified MHD flows in inclined rectangular ducts

This study investigates fully developed stratified gas/liquid magnetohydrodynamic (MHD) flow of an electrically conducting liquid and a nonconducting gas in inclined rectangular ducts subjected to a vertical magnetic field. Analytical and numerical solutions for the velocity and induced magnetic fields are obtained in terms of the governing dimensionless parameters for concurrent upward, concurrent downward, and countercurrent flows. Unlike single-phase MHD flow, duct inclination strongly affects two-phase flow by altering the liquid holdup and the relative contributions of gravitational, frictional, and electromagnetic forces. The results reveal a complex interplay among gravity, Lorentz forces, and wall and interfacial shear stresses. These interactions govern the liquid holdup, pressure gradient, multiple steady solutions, flooding limits, local backflow, jet-like velocity structures, and pumping requirements. Wall conductivity critically affects the induced magnetic field and Lorentz force distribution and therefore cannot be neglected, even at very small magnetic Reynolds numbers. Fully insulating ducts generally exhibit the weakest electromagnetic effects and behavior closest to non-MHD flow. Configurations with a conducting bottom wall exhibit substantially stronger electromagnetic effects and greater sensitivity to side-wall conductivity, leading to pronounced changes in the velocity field, liquid holdup, pressure gradient, gas-lubrication effect, and overall pumping-power requirements.

physics.flu-dyn↗

arXiv2026

Two-phase stratified MHD flows in rectangular ducts

The characteristics of two-phase stratified magnetohydrodynamic (MHD) flow in horizontal rectangular ducts are investigated for a system consisting of a conductive liquid and a non-conductive gas. Numerical and analytical solutions of the governing equations for the velocity and induced magnetic field intensity of fully developed laminar MHD flow are obtained for various combinations of bottom- and side-wall conductivities and for different orientations of an externally applied transverse magnetic field. The relevant set of dimensionless parameters governing the problem is identified. Unlike in single-phase MHD flows, the presence of a non-conductive gas layer breaks the flow symmetry, leading to a significantly different dependence of the flow characteristics on duct aspect ratio, wall-conductivity configuration, and the strength and orientation of the applied magnetic field. Using mercury-air flow as a representative test case, the solutions are employed to quantify the influence of the gas phase on the in-situ liquid holdup, velocity field, pressure gradient, flow lubrication, and pumping-power requirements. It is shown that, regardless of the magnetic Reynolds number, these characteristics are strongly affected by the wall-conductivity configuration and by the orientation of the external magnetic field.

physics.flu-dyn↗

arXiv2025

Long-wave instability of stratified two-phase MHD flow

Instability of a stratified two-phase MHD parallel flow between two infinite plates is addressed. We examine the effect of the transverse magnetic field on the base flow and long wave instability of a two-layer system consisting of conductive liquid and non-conductive gas. Both perfectly insulating and perfectly conducting boundaries are considered. To capture the behavior at small but finite wavenumbers, the conventional first-order long-wave stability analysis is extended to higher order terms. Using mercury-air system as a representative test case, the results demonstrate distinct and non-similar base flow and disturbance profiles, as well as different stability maps for insulating versus conducting boundaries. The stability diagrams reveal a non-monotonic influence of the magnetic field on flow stability, showing that, in addition to its expected stabilizing effect, the field can also induce destabilization under certain conditions. Inspection of the disturbance profiles indicates that despite the strong damping of mercury flow by the magnetic field, interaction of the two fluids at the interface and the shear-induced instabilities in the gas layer dominate and can lead to flow destabilization as the magnetic field strength increases.

physics.flu-dyn↗