The lattice Boltzmann method(LBM)for multicomponent immiscible fluids is applied to the simulations of solid-fluid mixture flows including spherical or nonspherical particles in a square pipe at Reynolds numbers of ab...The lattice Boltzmann method(LBM)for multicomponent immiscible fluids is applied to the simulations of solid-fluid mixture flows including spherical or nonspherical particles in a square pipe at Reynolds numbers of about 100.A spherical solid particle is modeled by a droplet with strong interfacial tension and large viscosity,and consequently there is no need to track the moving solid-liquid boundary explicitly.Nonspherical(discoid,flat discoid,and biconcave discoid)solid particles are made by applying artificial forces to the spherical droplet.It is found that the spherical particle moves straightly along a stable position between the wall and the center of the pipe(the Segr´e-Silberberg effect).On the other hand,the biconcave discoid particle moves along a periodic helical path around the center of the pipe with changing its orientation,and the radius of the helical path and the polar angle of the orientation increase as the hollow of the concave becomes large.展开更多
Transporting and storing hydrogen is a complex technological task.A typical problem relates to the need to minimize the strength of fluid motion and heat transfer near the walls of the container.In this work this prob...Transporting and storing hydrogen is a complex technological task.A typical problem relates to the need to minimize the strength of fluid motion and heat transfer near the walls of the container.In this work this problem is tackled numerically assuming an infinite cavity of pipe square cross-section,located in a constant external temperature gradient.In particular,a method based on the application of vibrations to suppress the gravitational convection mechanism is explored.A parametric investigation is conducted and the limits of applicability of the method for small Grashof numbers(10e4)are determined.It is shown that it is possible to minimize the intensity of the vibrogravitational flow for any values of the problem parameters if correction factors are specified.The results obtained can be applied in technological processes associated with the transportation,storage and use of hydrogen:pumping the working fluid through pipes,storage in tanks,as well as flow processes in the combustion chambers of power plants.展开更多
基金This work is partly supported by the Grant-in-Aid for Scientific Research(No.18360089)from JSPSthe COE program(the Center of Excellence for Research and Education on Complex Functional Mechanical Systems)of the Ministry of Education,Culture,Sports,Science and Technology,Japan。
文摘The lattice Boltzmann method(LBM)for multicomponent immiscible fluids is applied to the simulations of solid-fluid mixture flows including spherical or nonspherical particles in a square pipe at Reynolds numbers of about 100.A spherical solid particle is modeled by a droplet with strong interfacial tension and large viscosity,and consequently there is no need to track the moving solid-liquid boundary explicitly.Nonspherical(discoid,flat discoid,and biconcave discoid)solid particles are made by applying artificial forces to the spherical droplet.It is found that the spherical particle moves straightly along a stable position between the wall and the center of the pipe(the Segr´e-Silberberg effect).On the other hand,the biconcave discoid particle moves along a periodic helical path around the center of the pipe with changing its orientation,and the radius of the helical path and the polar angle of the orientation increase as the hollow of the concave becomes large.
基金carried out with financial support from the Russian Ministry of Education and Science,project FSNM-2023-0004“Hydrogen energy.Materials and technology for storage,transportation and use of hydrogen and hydrogen-containing mixtures”.
文摘Transporting and storing hydrogen is a complex technological task.A typical problem relates to the need to minimize the strength of fluid motion and heat transfer near the walls of the container.In this work this problem is tackled numerically assuming an infinite cavity of pipe square cross-section,located in a constant external temperature gradient.In particular,a method based on the application of vibrations to suppress the gravitational convection mechanism is explored.A parametric investigation is conducted and the limits of applicability of the method for small Grashof numbers(10e4)are determined.It is shown that it is possible to minimize the intensity of the vibrogravitational flow for any values of the problem parameters if correction factors are specified.The results obtained can be applied in technological processes associated with the transportation,storage and use of hydrogen:pumping the working fluid through pipes,storage in tanks,as well as flow processes in the combustion chambers of power plants.
