Numerical solution of the gas compression problem at a specified law of action

Author(s):  
Сергей Петрович Баутин ◽  
Юрий Владимирович Николаев

Выполнено численное моделирование одномерных течений политропного газа, описывающее сжатие покоящегося газа с плотностью 1 в покоящийся газ, сжатый до значения 10. Описываемое сжатие происходит без ударных волн эффективным с точки зрения энерговложения способом, так как энергия тратится только на сжатие газа, но не на его разгон Controlled thermonuclear fusion (CTF) is an almost unlimited source of energy and scientists have been studying it for several decades. This requires an efficient and stable compression of diyterium-tritium fuel to a very high density. This work addresses shockless one-dimensional (plane, cylindrical and spherical symmetry cases) “compression from rest to rest”, when gas from the initial resting state under the influence of an impenetrable piston is shocklessly transferred to a resting homogeneous state, but compressed by 10000 times. This compression is energetically most advantageous, because work is spent only on the compression, but not on the gas acceleration. Earlier [10] this problem was solved in the opposite direction of time change. In this case, a density jump occurs on the piston which was taken into account in calculations [3] at the final moment of compression. The numerical solution of this problem in the opposite direction of time variation allows calculating the trajectory of the compressing piston in the form of a set of points ( t,r ) at which the gas velocity and density are determined. In this paper, the problem of shockless “compression from rest to rest” is numerically solved in the forward direction of time change if the compressing piston trajectory is known. The compression piston moves along a monotonous trajectory away from the axis or center of symmetry. It is important, when calculating in forward direction of time change, no internal characteristics are initially entered. They, like all gas flow in the calculation area, are determined in the process of direct calculation. This indicates that the trajectory of compressing piston is the recommendation for appropriate physical experiments

1976 ◽  
Vol 98 (1) ◽  
pp. 111-116 ◽  
Author(s):  
A. Gu ◽  
L. Cziglenyi

Analysis and method of numerical solution for evaluating the performance of hydrostatic spherical gas gyro bearings at any gimbal angle and at any eccentricity have been developed. Performance data on load capacity, gas flow rate, drag torque, and error torque over some ranges of gimbal angle and eccentricity are presented. Comparison has been made between the equatorially vented and nonvented bearings of fixed bearing angles.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
M. Demianenko ◽  
M. Volf ◽  
I. Pavlenko ◽  
O. Liaposhchenko

Despite the rapid development of alternative energy sources, the role of hydrocarbons in the global fuel and energy balance remains significant. For their transportation and further processing, pre-processing is carried out using a set of equipment. In this case, the mandatory devices are separators. In terms of specific energy consumption and separation efficiency, methods based on the action of inertia forces are optimal. However, standard designs have common disadvantages. A method of dynamic separation is proposed to eliminate them. The proposed devices are automatic control systems. The object of regulation is hydraulic resistance, and elastic forces are the regulating actions. Aerohydroelastic phenomena accompany the operation of dynamic separation devices. Among them, the most interesting are flutter and buffeting. Oscillations of adjustable baffles accompany them. It is necessary to conduct a number of multifactorial experiments to determine the operating parameters of dynamic separation devices. In turn, physical experiments aim to identify patterns and features of processes occurring during vibration-inertial separation (i.e., the dependence of various parameters on velocity). Therefore, the article proposes a methodology for carrying our physical experiments on dynamic separation and a designed experimental setup for these studies. As a result, the operating modes of separation devices for different thicknesses of baffle elements were evaluated. Additionally, the dependences of the adjustable element’s deflections and oscillation amplitudes on the gas flow velocity were determined for different operating modes of vibration separation devices.


Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 892
Author(s):  
Haifeng Li ◽  
Zongshu Zou ◽  
Zhiguo Luo ◽  
Lei Shao ◽  
Wenhui Liu

COREX is one of the commercialized smelting reduction ironmaking processes. It mainly includes two reactors, i.e., a (reduction) shaft furnace (SF) and a melter gasifier (MG). In comparison with the conventional blast furnace (BF), the COREX MG is not only equipped with a more complicated top charging system consisting of one gimbal distributor for coal and eight flap distributors for direct reduction iron (DRI), but also the growth mechanism of its burden pile is in a developing phase, rather than that in a fully-developed phase in a BF. Since the distribution of charged burden plays a crucial role in determining the gas flow and thus in achieving a stable operation, it is of considerable importance to investigate the burden distribution influenced by the charging system of COREX MG. In the present work, a mathematical model is developed for predicting the burden distribution in terms of burden layer structure and radial ore/coal ratio within the COREX MG. Based on the burden pile width measured in the previous physical experiments at different ring radii on a horizontal flat surface, a new growth mechanism of burden pile is proposed. The validity of the model is demonstrated by comparing the simulated burden layer structure with the corresponding results obtained by physical experiments. Furthermore, the usefulness of the mathematical model is illustrated by performing a set of simulation cases under various charging matrixes. It is hoped that the model can be used as a what-if tool in practice for the COREX operator to gain a better understanding of burden distribution in the COREX MG.


1979 ◽  
Vol 21 (3) ◽  
pp. 197-203 ◽  
Author(s):  
G. M. Alder

The paper describes the numerical solution of the equations of compressible flow through axisymmetric convergent nozzles. The class of supercritical flows is considered, in which the gas velocities in the jet downstream from the throat are supersonic. The subsonic region of the flowfield is solved in the hodograph plane by a finite-difference method. The supersonic region is solved in the physical plane by the method of characteristics. The stream function distribution on the sonic line is adjusted iteratively to match the boundary conditions at the lip and free streamline. Discharge coefficients are evaluated and truncation errors in the results are considered.


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