| Abstrakt: |
A numerical study of the mixing processes of multicomponent gas flows with the help of static mixers was carried out to reduce the temperature and gas mixture composition inhomogeneities in the fuel pipeline. The literary sources of interest for this work are analyzed. Two types of static mixer are selected: a series of elements from a twisted band and a leaf mixer. For these designs, numerical calculations are made at the specified parameters of mixing gas flows containing methane, hydrogen, and nitrogen. Turbulent flows of the mixture were modeled in a stationary formulation using the equations of conservation of mass, momentum, and energy averaged by Reynolds. Two-parameter models with wall-side functions were used to determine turbulent viscosity. As boundary conditions at the entrance to the static mixer, the fields of the desired variables, obtained earlier by the authors of this article at the exit from the T-shaped mixer with Reynolds numbers (4–6) × 106 in the main and adjacent pipes for the supply of fuel mixture components, were set. The analysis of the efficiency of the mixing process using stationary mixers of various modifications was carried out. The fields of the components of speed, temperature, and mass fractions of the mixture at the exits from static mixers were obtained and pressure losses in the structures were determined. The optimal design of the mixer is proposed, which consists of four elements in the form of a 180° plate, each element of which has a length (half-spin period) equal to two diameters of the pipe. Adjacent elements are twisted in opposite directions and adjoin each other at an angle of 90°. It is shown that it is possible in a fragment of the fuel pipeline, including a static mixer and a straight section of the pipe with a length of not more than five diameters, to achieve the required uniformity of the composition and temperature of the fuel mixture in the outlet section of the said fragment. [ABSTRACT FROM AUTHOR] |
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