The authors have upgraded an experimental stand that simulates energy-loaded elements of thermonuclear installations. This indicates a significant increase in the efficiency of the work area. In the measurements of the heat exchange of a high-temperature surface with a dispersed flow of released water, the values of exceeding the heat flow level of 7.1 MW/m2 were measured, with a heat transfer coefficient of 151 kW/(m 2 ×K). The excess pressure of the coolant at the inlet to the nozzle is (1.5–3.5) × 10 5 Pa), the mass flow rate of the coolant (distilled water) is (4.0–6.0) × 10 –3 kg/s, the irrigation density was changed within (4.2–6.2) kg/(m 2 ×s). These values of thermophysical quantities correspond to the values applicable to modern experimental thermonuclear facilities. For the calculated thermophysical values, graphic dependences were obtained for the entire time. Comparison with similar results of other authors is made.
The article discusses analysis of geometric obstacles in computer-aided assembly planning. An important concept of a geometric situation is introduced. This is such a connected and coordinated set of parts that requires a test of freedom from geometric obstacles. The axiom of geometric heredity is formulated and two algebraic models of a complex technical system are proposed. It is shown that the set of all assembled fragments of the product, which are free from geometric obstacles, forms a lattice. This makes it possible to solve the problem of geometric analysis of assembly processes by algebraic methods
The simulation system MTSS is a visually interactive process-oriented discrete simulation system. With use of the simulation system MTSS a number of models of mining machines, and models of coalmine subsystems such as a working face, an underground conveyor network, a pumping subsystem, and a power supply subsystem were developed. To combine these heterogeneous models in the simulation system MTSS the possibility of distributed simulation is implemented. To implement this possibility, the High Level Architecture standard and Runtime Infrastructure Pitch pRTI Free was used. As an example of the use of distributed simulation, a federation consisting of two federates from a simulation model of a coalmine working face and a simulation model of a belt conveyors network of a coalmine is presented.
The cooling of surfaces that perceive high heat flows (more than 7 MW/m2) at the current rate of development of the energy sector will become one of the main problems of the near future. Already at the moment, during the construction of the experimental thermonuclear reactor ITER, located in the Center for technological research of Cadarache, France, there is a need to divert the heat flux density of about 10 MW/m2 to maintain stable operation of the reactor. In this article, it is proposed to use a method of heat exchange intensification using a two-component dispersed flow. The effectiveness of this cooling method is due to the use of the latent heat mechanism of the phase transition instead of the convective heat transfer mechanism. The paper describes the experimental setup, the method of measuring and conducting the experiment, as well as the results obtained. The highest value of the diverted heat flux density obtained as a result of processing experimental data is 11.2 MW/m2, with a coolant flow rate of 0.025 kg/s. The experimental data results indicated in the article reveal the possibilities of using a dispersed two-component flow and indicate the high efficiency of the proposed cooling method.
Usually, the generation of electricity from the conversion of a mechanical rotation energy requires the adjustment of the level of not only the output power, but also the voltage. Changes in the speed of rotation of a generator rotor, as well as load drops and surges, can lead to a deviation of the voltage value from the nominal one. That is why generators with permanent magnets on the rotor are of limited use where stability of the output voltage is required. This article describes the design of a brushless generator which does not have the disadvantages of currently used generators with permanent magnets, and with excitation windings on the rotor. The proposed generator does not have windings on the rotor. Accordingly, it does not have brushes, and can work for a long time without any maintenance. It can be used in wind turbines, generators of ships, and superconducting sources.
