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Vol 73, No 6 (2018)
- Year: 2018
- Articles: 5
- URL: https://journals.rcsi.science/0027-1330/issue/view/10031
Article
Effect of Quartz Deposition on the Dynamics of Magma Chamber Degassing
Abstract
The filtration of a supercritical brine flow during the magma chamber degassing is numerically simulated with consideration of quartz transport and deposition. It is shown that the quartz deposition and the accompanying decrease of permeability reduce the size of the concentrated brine lens formed above the magma chamber. The effect of rock hydraulic fracture on the lens formation is studied. An unsteady degassing regime is revealed; this regime is associated with a periodic increase and decrease in permeability due to the hydraulic fracturing and quartz deposition. The obtained numerical results are in agreement with the geological data on the structure of copper deposits.
129-134
Programmed Strategies to Test the Quality of Line-of-Sight Guidance Control Using Video Images
Abstract
A particular case of the game problem formulated in our previous paper is considered. As a model of a moving platform, we use an extended model of the Dubins car. An existence condition for a saddle point and a method of its finding are proposed. A method of determining the strategies and trajectories of players is discussed.
135-140
Brief Communications
Motion of a Melting Particle
Abstract
The motion of a single melting spherical particle in its own melt is considered. A formula for the thrust appearing due to flow around the melting particle is derived. The self-similar melting problem is solved for a particle at rest in a quiescent melt to determine the radius of the particle. For a small Reynolds number, it is shown that there exists a critical temperature difference between the particle and the melt such that the accelerating and decelerating modes of motion are separated.
141-144
Stability of the Rectilinear Motion of an Omni Vehicle with Consideration of Wheel Roller Inertia
Abstract
The dynamics of a mobile vehicle with three omni wheels is considered for the case when the vehicle moves on a fixed perfectly rough plane by inertia. In order to study the effect of wheel roller inertia on the stability of the rectilinear motion of the vehicle, the fore wheel is modeled by the following rigid bodies: a wheel disk and a supporting roller such that the roller does not slip with respect to the plane. The rear wheels are modeled by disks slipping without friction in the direction perpendicular to their planes (an inertialess model of an omni wheel). We propose some dynamic equations of motion of the vehicle in the form of Tatarinov’s laconic equations for systems with differential constraints. These equations are related to the dynamic equations obtained for a vehicle with three inertialess omni wheels. The stability of rectilinear motions is analyzed.
145-148
The Shape of the Crater Formed by an Explosive Wedge-Shaped Cord Charge on the Ground Surface
Abstract
The explosion of a wedge-shaped cord charge on the ground surface is considered in the solid–liquid formulation of the pulsed-hydrodynamic model. The general solution to this problem is obtained. A parametric analysis is performed. The dependence of the shape and size of the explosion crater on the constitutive parameters is analyzed.
149-152