Non-isothermal flow of a non-newtonian fluid with the free surface in a coaxial channel

Non-isothermal non-Newtonian fluid flow implemented during filling a coaxial channel in the gravity field is investigated with regard to the dissipative heating, the temperature dependence of the effective viscosity, and the presence of the free surface. The rheological behavior of the medium is described by the Сross-WLF model. The problem is solved numerically using the original computational technology based on the control volume approach and the method of invariants for satisfying the boundary conditions on the free boundary. The flow characteristics in the process of filling are demonstrated for various values of the constitutive parameters

The impact of viscous dissipation on the flow parameters during round tube filling

The fountain non-isothermal flow of a viscous fluid realized during circular pipe filling is investigated. The mathematical basis of the process is formed by the equations of motion, continuity and energy with respective initial and boundary conditions with due account of the temperature dependence of viscosity, the presence of a free boundary, and dissipation of mechanical energy. To solve the problem numerically, a finite difference method is used. Depending on the values defining the dimensionless parameters, the results of parametric studies in temperature, viscosity, dynamic and kinematic characteristics of the flow are shown. Flow patterns for the formulation of problems with different initial and boundary conditions are given. The distributions of velocity and temperature in different cross sections of the pipe and the shape characteristics of the free surface are presented. The separation of flow into the zone of spatial flow in the vicinity of the free surface and one-dimensional flow away from it, and changing the shape of the free boundary, depending on the level of dissipative heating, are demonstrated

The impact of viscous dissipation on the flow parameters during round tube filling

The fountain non-isothermal flow of a viscous fluid realized during circular pipe filling is investigated. The mathematical basis of the process is formed by the equations of motion, continuity and energy with respective initial and boundary conditions with due account of the temperature dependence of viscosity, the presence of a free boundary, and dissipation of mechanical energy. To solve the problem numerically, a finite difference method is used. Depending on the values defining the dimensionless parameters, the results of parametric studies in temperature, viscosity, dynamic and kinematic characteristics of the flow are shown. Flow patterns for the formulation of problems with different initial and boundary conditions are given. The distributions of velocity and temperature in different cross sections of the pipe and the shape characteristics of the free surface are presented. The separation of flow into the zone of spatial flow in the vicinity of the free surface and one-dimensional flow away from it, and changing the shape of the free boundary, depending on the level of dissipative heating, are demonstrated

Change of triglyceride composition of Cucurbitaceae and Taraxacum officinale seed oil during ripening

yesThe change of triglyceride composition in seeds of certain plants of the Cucurbitaceae family and Taraxacum officinale during ripening was studied by HPLC. A small decrease in the content of palmitic derivatives in Cucurbitaceae seed oil and a questionable change of the triglyceride composition of T. officinale seed oil were found. Data for the triglyceride composition were compared with calculations performed assuming an equally probable statistical distribution of fatty-acid radicalsBelgorod State Universit

Incremental approach to hplc analysis of anthocyans

Relative analysis and relative incremental analysis, which can substantially simplify the determination of anthocyanidine glycosides without using standards, were used to determine anthocyans from plant materials by reversed-phase HPLC. The compositions of anthocyans from several plants grown in Belgorod district were investigatedyesBelgorod State Universit

Change of triglyceride composition of Cucurbitaceae and Taraxacum officinale seed oil during ripening

The change of triglyceride composition in seeds of certain plants of the Cucurbitaceae family and Taraxacum officinale during ripening was studied by HPLC. A small decrease in the content of palmitic derivatives in Cucurbitaceae seed oil and a questionable change of the triglyceride composition of T. officinale seed oil were found. Data for the triglyceride composition were compared with calculations performed assuming an equally probable statistical distribution of fatty-acid radicalsyesBelgorod State Universit