Calculation of evaporation of a twisted flow of cryogenic fluid in leidenfrost film boiling with allowance for the initial section

A mathematical model of evaporation of a twisted flow if a cryogenic fluid developed by the authors is supplemented by the calculation of an initial section. Calculational and experimental results are compared. Kazan State Technical University. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 69, No. 5, pp. 741–747, September–October, 1996.     

Effect of a constant electric field on the film flow of a liquid dielectric

The method and results of an experimental investigation into the effect of a constant electric field on the flow of a liquid dielectric film over a vertical surface are described.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 48, No. 3, pp. 432–436, March, 1985.     

Experimental study of unsteady heat transfer from a gas-suspension flow in the initial section of a cylindrical channel

Data are presented from experimental studies of unsteady heat transfer from a gas-suspension flow in a short cylindrical channel with an increase in the thermal load over time.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 42, No. 6, pp. 885–892, June, 1982.     

Heat transfer on the inlet section of a tube at increased levels of initial flow turbulence

The authors report the results of an experimental study of heat transfer on the initial section of a tube with uniform velocity profile at the inlet and a degree of flow turbulence up to 20% in the range of Reynolds numbers from 10⁴ to 10⁵.     

Instability of a two-dimensional film flow with inhomogeneous temperature field on the free surface

It is shown that a two-dimensional stationary flow of a thin liquid film with inhomogeneous temperature distribution on the free surface exhibits a local longwave instability. A critical condition for the transition to a regular three-dimensional flow with a “stream” structure is formulated and an expression for the characteristic period is derived.     

Heat exchange in the initial section of a pipe with laminar flow in the boundary layer and a constant wall temperature

Equations are proposed for calculating the local and average coefficients of heat exchange in the dynamic initial section of a round pipe with laminar flow in the boundary layer and a constant wall temperature.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 34, No. 4, pp. 581–588, April, 1978.     

Certain features of coherent flow structure development in the initial section of three-dimensional turbulent jets

Results of an experimental investigation of regular, large-scale, vortex structures in three-dimensional submerged jets are elucidated.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 47, No. 4, pp. 537–543, October, 1984.     

Influence of the concentration initial section on the magnitude of diffusion fluxes in turbulent fluid flow

Results of an experimental investigation of the influence of initial sections of a mass delivery surface on values of the Stanton number are presented.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 32, No. 5, pp. 856–859, May, 1977.     

电磁流量计椭圆截面管道流场仿真研究

通过ICEM CFD软件将局部截面变为椭圆形的异径导流筒进行了三维建模,使用Fluent对不同入口速度下的流线场与速度分布进行仿真计算,建立了不同结构的导流筒所适用的速度范围.结果表明,速度的大小和椭圆截面离心率对流场产生的影响较大.当速度减小或离心率变大时,导流筒尾部渐扩管容易发生回流,致使流场紊乱.本研究能为椭圆形管道电磁流量计的结构设计提供参考方案,为设计合理的导流筒提供理论依据.     

Motion of a viscous fluid in the initial section of a flat channel

The laminar flow of a viscous incompressible fluid in the initial section of a flat channel is investigated on the basis of the linearized boundary layer equations. Formulas are obtained for the longitudinal velocity component and the friction at the wall. The approximate and exact solutions are compared, and the agreement is shown to be satisfactory.     

Heat exchange in a draining liquid film in the initial thermal part

An approximate solution of the heat-transfer problem in a draining liquid film with a parabolic velocity profile and boundary conditions of the second kind is given.     

Laminar heat transfer over the initial section of a rectangular channel

The author describes a study, based on the linearized energy equation, of heat transfer over the initial section of a rectangular channel with a laminar incompressible flow and both uniform and nonuniform temperature fields at the inlet. Temperature and Nusselt number distributions over the channel perimeter are given.     

Thinning of a superfluid film in persistent flow

Persistent flow of a saturated helium film confined in an annular volume has been induced by rotation. Measurement of the change in film thickness when the flow is destroyed by a heat pulse showed good agreement with the Kontorovich prediction that the moving film is thinner, even after flow times of several hours. The cell geometry is such that any effect of the vapor on the thinning can be discounted.Supported financially by the National Research Council of Canada.     

Heat exchange on the initial thermal section in stabilized turbulent air flow in circular pipes and rectangular channels

Formulas are proposed for an analysis of the local and mean heat exchange on the initial thermal section for stabilized turbulent air flow in circular pipes and rectangular channels on the basis of an extension of test results.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 20, No. 2, pp. 215–223, February, 1971.     

Velocity measurements in a convective flow by holographic interferometry

A holographic interferometry technique has been developed that can be used to measure the three components of the velocity field in a whole plane of a fluid flow simultaneously. The light scattered from an illuminated fluid plane is recorded on a hologram. Several interferograms are obtained in the reconstruction of the hologram. Each interferogram is automatically analyzed and produces quantitative information about one velocity component. Parameters that affect the quality of the interferograms are analyzed. The technique is demonstrated in a Rayleigh-Bénard convective flow. Holographic interferometry and particle image velocimetry techniques are compared.     

Properties of a superconducting film in a perpendicular magnetic field

On the basis of the Ginzburg-Landau free energy, the magnetization and the shear modulus of the vortex lattice is calculated for various values of the Ginzburg-Landau parameter κ and of the film thickness. Agreement is found with recently measured values of the shear modulus.     

Nonisothermal film flow of a magnetizable liquid

The problem of the flow of a nonisothermal magnetizable liquid with a free surface in a nonuniform magnetic field is formulated and investigated theoretically by considering a specific example.Notation H magnetic field intensity - M magnetization - _o magnetic permeability of vacuum - I current (r, , z), cylindrical coordinates - (, gz) coordinates of free surface - R radius of current-carrying conductor - p pressure - v axial component of velocity - viscosity - R₁, R₂ principal radii of curvature of surface - surface tension - Q flow rate of liquid - G characteristic value of gradient of magnetic field intensity - density - g acceleration due to gravity Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 37, No. 5, pp. 881–885, November, 1979.     

The effect of electric field on the formation and fragmentation of condensate film on the walls of a capillary in a flow of steam

An experimental investigation is performed of the effect of electric field on the parameters of a condensate film forming on the walls of a capillary in which hot steam flows. The increase in the field intensity in the vicinity of the capillary exit section causes a variation of the two-phase mode of flow in the capillary from annular to slug; the shape of the film surface varies from smooth to wavy; and the formation of large droplets at the capillary exit section changes to pulsating fragmentation of the film. With continuing increase in the intensity, the slug flow changes back to annular, water forms steady-state projections at the capillary exit section, the fragmentation of the film becomes monotonic, and an unsteady corona discharge arises on the projections. The variation of the capillary orientation from horizontal to vertical results in an increase in the intensity required for the development of the slug mode of flow. A mechanism of monotonic fragmentation of film is suggested, within which the characteristics of resultant fragments are assessed.     

Vortex equilibrium in film flow near a defect

A simple model based on numerical simulations in bulk is used to examine the pinning characteristics of vortices in helium films adsorbed in the vicinity of substrate defects. The film profile in the absence of a vortex is first calculated including both the Van der Waals potential of a bump defect and surface tension. The displacement and ultimate de-pinning of a vortex line constrained within the profile is then followed as a function of an imposed superfluid flow. The behavior of the vortices lends insight into recent experimental results sensitive to the presence of pinned vortices and indicates that the relevant pinning sites are atomic in dimension.     

Thermal entry zone of a film flow

A simplified solution for the thermal entry zone in the stabilization of a film is confirmed by experiments at Re 450 for boundary conditions of the first type.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 51, No. 6, pp. 892–896, December, 1986.