Dmitry Anatolievich Koroteev

Modeling of Pore-Scale Two-Phase Phenomena Using Density Functional Hydrodynamics

Predictive modeling of pore-scale multiphase flow is a powerful instrument that enhances understanding of recovery potential of subsurface formations. To endow a pore-scale modeling tool with predictive capabilities, one needs to be sure that this tool is capable, in the first place, of reproducing basic phenomena inherent in multiphase processes. In this paper, we overview numerical simulations performed by means of density functional hydrodynamics of several important multiphase flow mechanisms. In one of the reviewed cases, snap-off in free fluid, we demonstrate one-to-one comparison between numerical simulation and experiment. In another case, geometry-constrained snap-off, we show consistency of our modeling with theoretical criterion. In other more complex cases such as flow in pore doublets and simple system of pores, we demonstrate consistency of our modeling with published data and with existing understanding of the processes in question.

Discontinuity breakdown on shock wave interaction with nanosecond discharge

Discontinuity breakdown conditions were experimentally realized by instant energy input in front of a plane shock wave. A shock tube and a special type of transversal nanosecond electric discharge with plasma electrodes were used for this research. A two-dimensional (2D) numerical simulation under experimental conditions has been undertaken. The pressure, density, temperature, and velocity fields have been examined. A comparison of numerical data and shadow images of a 2D flow after shock wave interaction with the discharge area was conducted. The geometry of the disturbed flowfield was found to be in good correspondence with one from numerical calculations. The results of the investigation also showed that, by using the described experimental setup, it is possible to achieve a special type of Richtmyer–Meshkov instability without applying an additional curved diaphragm.

Sedimentation of particles in shear flows of viscoelastic fluids

An experimental investigation of sedimentation of single particles and concentrated suspensions in Couette flows of viscous and viscoelastic fluids is presented. With the passage from viscous to viscoelastic fluids, a slowing down of the sedimentation was observed. The sedimentation of suspensions in viscoelastic fluids accelerated with increase in the suspension concentration. The development of instabilities during the sedimentation was detected.

When shock is shocked: Riemann problem dynamics at pulse ionization of a shock wave

We study the dynamics of the gas flow discontinuities after pulse ionization of a half space in front of a flat shock wave moving in a channel. Pulse volumetric electric discharge initiated in the vicinity of the shock concentrates in front of the shock and heats the gas there. The heating is shown to be very rapid. We use the shadow imaging technique and a high speed camera to study the flow pattern evolution after the discharge. The pattern consists of two shocks separated by a contact surface. This structure corresponds to the classical Riemann problem formulation. Based on the observed pattern, we estimate the amount of discharge energy converted to heat during the discharge time: the rate of temperature increase is in the order of several degrees K per nanosecond.

Two Modes of Shock Interaction with Zone of Pulse Volume Discharges in the Channel

A great number of researches in the recent years deal with the problem of non-equilibriums plasma flow control in aerodynamics [1]. Different approaches are used for efficient flow moderation with energy deposition in a boundary layer, compression wave area, duct inlets and others [1, 2, 3]. Energy input using pulse discharge plasmas appeared to be rather promising. Pulse and pulse-periodic energy supply is the most effective way to improve high-speed flow characteristics; shock waves arising from local pulse energy input area may influence high speed flow with shock configurations.

Shock wave interaction with nanosecond transversal discharges in shock tube channel

Discontinuity breakdown conditions were realized experimentally by instant homogenous energy input in front of shock wave. Energy deposition was conducted using nanosecond gas discharges in spatial and surface area. A shock tube and special type of nanosecond electric discharge with plasma electrodes were used for this research. One and two-dimensional numerical simulation under experimental conditions has been undertaken. Pressure, density, temperature and velocity fields have been examined. Comparison of numerical data and schleiren images of shock wave after its interaction with discharge area was conducted. The configuration of disturbed shock wave was found to be in a good correspondence with one from numerical calculations. Numerical results showed possibility to achieve Richtmyer-Meshkov type instability without membrane.