The flow of a viscous liquid layer in an open inclined channel under the turbulent mode is considered in this paper. To describe turbulent viscosity, the Van Driest model is used. The spectrum of characteristic values of the problem on linear stability of a plane-parallel flow is studied numerically. Parameters of the maximal growth waves are found out, the surface tension effect is studied, and theoretical results are compared with experimental data.
In thin films of liquid falling over an inclined surface random (or non-random) small dry spots shut and disappear or expand into the large-scale dry spots depending on the initial spot sizes and parameters of the liquid film. On consideration of the gravity forces, inertial forces of the film and surface tension, affecting the elements of a roller surrounding the dry spot, we have formulated a criterion, which helped us to answer the following question: if this spot shuts or not? This criterion includes the numbers of Bond and Reynolds and the contact wetting angle as the determining parameters. It is generalization of the known Hartley
The fluorescence method was used to measure the instantaneous thickness field of the falling non-isothermal water film. The process of rivulet formation in a heated film was registered. Measurement averaging allowed determination of the degree of transverse deformation of a film. In the lower half of the heater within the interrivulet zone of the non-isothermal film, the wave amplitude decreases with a rise of the heat flux and reduction of the average thickness. Two zones of the heat flux effect on liquid film deformation were distinguished. At low heat fluxes, the film flow is weakly deformed. At high heat fluxes the thermal-capillary forces provide formation of rivulets and a thin film between them.
Calculation data for characteristics of concave holographic arrays are reported, allowing development of low-size spectrometers with medium and high spectral resolution. The holographic arrays were fabricated around new subnanostructured films of chalcogenide semiconductors. A medium-resolution, small-size spectrometer was used to measure the distribution of temperature in the gas flow emanating from a DC plasmatorch with sectioned inter-electrode insert by the relative-intensity method. Presently available methods for measuring the temperature of non-uniform optically thin plasma were employed. A comparison of spectral and thermophysical methods for temperature measurements is given.
Estimation criteria for contribution of the main energy sources and sinks to complex heat transfer of the rod thermal cathodes were obtained for the quasi-one-dimensional statement of the heat problem. Criterial relationships allow determination for operation temperatures of the high-current long cathodes. A method for optimization of the electrode thermal state was developed. Calculations by the criterial method correlate with the experimental results.
Peculiarities of the formation of melt hydrodynamics in the molten pool of electric arc as a result of a viscous interaction with the arc plasma flow and the effect of electromagnetic forces are considered. It is shown that in a relatively shallow pool, the role of viscous interaction with plasma flow predominates electromagnetic forces. In a deeper pool, the flow in peripheral upper region is formed as before by a viscous interaction between plasma and melt, and the electromagnetic forces dominate in deep regions.
An extremal problem is formulated for computing the distributions of pressures, flow rates, and temperatures in the steady operation regime of thermal network of arbitrary configuration from data of measuring these parameters at individual network points. For its solution, it is proposed to use a non-conventional mathematical model of a non-isothermal flow distribution whose peculiarity is the invariance to flow directions, which are not known in advance. The approach and the computational scheme for estimating the parameters of the thermal/hydraulic regime are proposed and tested with a numerical example.
For the purpose of the development and introduction of the arrangements aimed at increasing the slagless power, economy, and reliability of the P-67 boiler of the 800 MW unit of the Berezovskaya Power Plant No.1, the variation of heat-engineering characteristics of the coal (lignite) of the open-cast mine
The scheme and cycle of a promising highly economic coal-dust combined steam-cycle power unit are presented. The flow-rate, thermodynamic, and design figures of high-temperature sets (a coal-dust boiler and a high-temperature steam turbine) are considered.
The paper described the creative path of K.E. Tsiolkovsky, the founder of theoretical cosmonautics, who devoted his life to solving various problems in the field of aerodynamics and rocket engineering, creating dirigibles with a metallic shell, jet planes, and air-cushioned trains, and studying the origin of planets, the Sun, and the Universe. The main engineering proposals of a scientist of great originality, which found applications in modern rocket and space engineering, are briefly analysed. The versatility of his interests is demonstrated; his research is shown to deal with many fields of science and technology, including the kinetic theory of gases, geology, cosmology, biology, philosophy, sociology, theology, and language science.
