Mathematical simulation of the near-bottom section of an ascending twisting flow

The available results of laboratory experiments on the formation of free vortices and controlling of their behavior are compared with the results of mathematical simulation of corresponding flows. This is accomplished by constructing solutions for a set of gas dynamics equations. The comparison is performed for a specific scheme of origination and functioning of free ascending twisting flows. In particular, it is shown that the experimental results confirm the proposed scheme of the origination and initial twisting of ascending vortex flows and validate the reason of their stable functioning with the help of the method intended for controlling generated vortices using vertical grids which was implemented in the experiments. The fact of origination of an ascending flow twisting and its directing is mathematically substantiated using the solution to a specific initially edge problem for a set of gas dynamics equations. A stationary flow whose parameters are close to gas-dynamic parameters of free vortices reproduced in the experiments is calculated.     

The Usage of Error Compensation Tools of CNC for Vertical Milling Machines

The error of metal-cutting machines must be kept within standard limits when a numerical control system is first introduced. A mechanism for more precise control of the motion is proposed on the basis of control modules in the core of the CNC. The results of using the proposed approach when the AxiOMA Control numerical control system is introduced at the Quaser MV184 machine tool (produced by “KEMZ” Ltd.) are outlined.     

Reference 1st grade meter of laser radiation power

Measurement Techniques -     

Parameter certification for the elastic components in string transducers

Measurement Techniques -     

Effect of the Location of the Detonation Initiation Point and the Position of the Air–Fuel Cloud on Explosion‐Field Parameters

The effect of the location of the initiation point on explosionfield parameters is studied numerically using as an example the detonation of a stoichiometric mixture of propane with air. The shape of the cloud of the mixture (toroid) and the ratio of its dimensions in calculations are typical of the volumes of air–fuel mixtures formed in accidents. The effect of the initiation point location within the cloud cross section was studied with variation in the position of the lower edge of the cloud above the underlying surface.     

Numerical analysis of the burning of pulverized coal with different thermal properties in the furnace of a BKZ-420-140-2 boiler

Results are presented from numerical simulations of mass-transfer and combustion processes in the furnace of a BKZ-420-140-2 boiler using the applied program package FIRE 3D with replacement of the design ékibastuz coal by Kuznetsk grade D hard coal and Irsha-Borodino grade 2B lignite.     

Critical currents in YBaCuO ceramics

Magnetization measurements on a ceramic YBaCuO sample were carried out. TheM(H, T) dependence has demonstrated some peculiarities which we assume are connected withH _j1,H _j2,H _c1 fields. By analyzing the magnetization in the field region betweenH _j1 andH _j2 within the framework of the critical state model, one obtains the dependence of the intergranular critical current density on field and temperature.     

Influence of the Operating Time of a Surface Heated by Electric Current on the Heat-Transfer Coefficient of Kerosene and Water Boiling on It

Results of experimental investigation of the influence of the operating time of a heating surface on the intensity of heat transfer in the kerosene and water boiling on it are presented. The experimental data on the heat transfer in the indicated liquids boiling on unrun heating surfaces have been generalized using different relations. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 78, No. 3, pp. 134–140, May–June, 2005.