Calculation of a three-dimensional turbulent cascade flow

A three-dimensional steady incompressible viscous flow through a plane cascade of turbine blades has been analyzed through a numerical method based on the Navier-Stokes equation. Particular attention is paid to the prediction of secondary flows occurring due to the endwall boundary layer and the blade geometry. A standard k- model is used for the modelling of Reynolds stress and boundary-fitted coordinates are adopted to represent the complex blade geometry accurately. Two differencing schemes are applied to the convective terms to investigate the effect of numerical diffusion. Experimental data obtained for the flows through the Langston cascade are selected for code validation. Computed results for the velocity vectors and static pressure distributions are in good agreement with presious measurements and provide validity of this numerical method. Three-dimensional viscous flow phenomena and the distribution of total pressure loss caused by secondary flows are also reasonably well predicted.List of symbols A _w area of the control volume surface - a coefficient of the discretized equation - B product of the transformation matrix - b transformation matrix - C _x axial chord of the airfoil - C _p pressure coefficient - C _pt total pressure loss coefficient - mass-averaged total pressure loss coefficient - C ₁, C ₂, C coefficients of the standard k- model - E constant used in the law of the wall - unit vectors in the Cartesian coordinate system - F mass flux through the control volume surface - f linear interpolation constant - G production term in the turbulent kinetic energy, or the contravariant velocity - J Jacobian - k turbulent kinetic energy - L characteristic length - l ⁺ nondimensionalized vertical distance from the wall - p pressure - p _t total pressure     

Cylindrical poiseuille flow of a Fermi liquid

The integral equation for cylindrical Poiseuille flow of a general excitation gas is derived for diffuse scattering at the wall. For a degenerate Fermi gas or liquid the flow through a circular cylindrical tube is determined numerically by a variational method.     

Calculation of the statistical characteristics of a turbulent flow under the action of external forces

A study is made of the statistical characteristics of isotropic velocity and scalar fields in supply of the kinetic energy of turbulence from the energy of the average flow. Two models based on the distributions of the kinetic turbulence energy and the intensity of scalar-field pulsations by wave numbers and length scales are used for calculation of the statistical characteristics of turbulent velocity and scalar fields. The calculation results are compared to the data of the direct numerical modeling performed under the same initial conditions. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 79, No. 1, pp. 148–154, January–February, 2006.     

Measuring the dynamic characteristics of turbulent liquid flow

Conclusion Recording hydrodynamic pressure pulsations with inductive and capacitive instruments makes it feasible not only to determinè quantitatively the amplitude and the frequency of such a pulsation at the flow boundary but also to discover what the physical parameters of the flow are within a wide range of velocities and pressures under either natural or laboratory conditions. The knowledge of laws which govern the occurrence, the buildup, and the distribution of pulsating pressure at the flow boundary is important both practically and scientifically, as it enables one to account correctly for the forces which produce vibration in dams, in hydroelectric-plant structures, in guarding locks, etc.Translated from Izmeritel'naya Tekhnika, No. 8, pp. 45–47, August, 1972.     

Calculation of a turbulent monodisperse flow in an axisymmetric channel

A stationary isothermal model of the aerodynamics of a two-phase flow in an axisymmetric channel has been constructed with allowance for the turbulent and pseudoturbulent mechanisms underlying the transfer of the solid phase momentum. The equations of dispersed phase motion are closed at the level of the equations for the second moments of the pulsation velocities of particles, whereas the equation of momentum transfer of the carrier is closed on the basis of a one-parameter model of turbulence extended to the case of two-phase turbulent flows. The results of calculations are compared with experimental data. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 81, No. 5, pp. 844–855, September–October, 2008.     

Magnetohydrodynamic poiseuille flow through a porous medium

Abstract

This paper is concerned with formulating equations for the flow of an electrically conducting fluid through a non‐conducting porous medium with non‐porous and non‐conducting boundaries. Equations are developed for the general case of the flow of a solid‐fluid suspensions; flow through a porous medium is treated as a special case by letting the velocity of the particle phase goes to zero. Two cases are considered. Exact solution is obtained for the case of flow between parallel plates, but for flow in pipes of square and circular cross sections, the equations have to be solved numerically. The numerical technique developed can treat elliptical cross sections as well. The flow in all cases is assumed to be steady, laminar, incompressible, viscous, and fully developed. The results are presented in terms of a parameter which measures the resistance of the porous medium.     

Calculation of electric arc interaction with a turbulent gas flow

The characteristics of an electric arc in a turbulent gas flow are studied. Relationships for calculating turbulent transport are presented.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 54, No. 4, pp. 550–557, April, 1988.     

Calculation of the characteristics of particles in inhomogeneous turbulent streams

The influence of inertia, averaged phase slip, and inhomogeneity of the turbulent carrier stream on the parameters of the disperse phase in the flow of a gas suspension in a round pipe is investigated on the basis of a closed system of equations for the first and second moments of particle velocity pulsations.G. M. Krzhizhanovskii Scientific-Research Power Institute, Moscow. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 62, No. 4, pp. 539–545, April, 1992.     

Structure and characteristics of detached turbulent flow in a cavity

The results of an experimental investigation of the turbulence characteristics of detached flow in a channel with a rectangular cavity are given.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 48, No. 3, pp. 387–391, March, 1985.     

Some characteristics of thin shear layers in homogeneous turbulent flow

Tomographic particle image velocimetry measurements of homogeneous isotropic turbulence that have been made in a large mixing tank facility at Cambridge are analysed in order to characterize thin highly sheared regions that have been observed. The results indicate that such regions coincide with regions of high enstrophy, dissipation and stretching. Large velocity jumps are observed across the width of these regions. The thickness of the shear layers seems to scale with the Taylor microscale, as has been suggested previously. The results discussed here concentrate on examining individual realizations rather than statistics of these regions.     

Influence of wall elasticity and poiseuille flow on peristaltic induced flow of a particle-fluid mixture

The effect of Poiseuille flow on peristaltic transport of a particle-fluid mixture has been investigated in a two-dimensional mathematical model for the case where the walls of the channel execute sinusoidal motion of small amplitude. The driving mechanism of the muscle is represented by assuming the channel walls to be elastic or viscoelastic. The fluid-particle interaction problem is investigated by considering equations of motion for both the fluid and particle phases with the deformable boundaries. The wall characteristics appear in their equations of motion, which are solved to represent boundary conditions of the fluid motion. Solutions for free pumping case and interaction with Poiseuille flow are obtained for small values of Poiseuille flow parameter in closed form as well as by a series method. The effect of the particulate phase is observed throughout the analysis both qualitatively and quantitatively.     

Calculation of turbulent gas jets

A technique is proposed for calculating jets with variable density. The variations of the basic parameters of a jet are obtained and they are compared with experimental data.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 42, No. 3, pp. 395–402, March, 1982.     

Study of the simplest statistical characteristics of a turbulent flow temperature distribution

The degeneracy of the temperature distribution in homogeneous nonisotropic turbulence is examined. The relations obtained are verified experimentally.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 30, No. 6, pp. 1025–1034, June, 1976.     

Dynamic characteristics of pulsating turbulent flow of compressible gas in a channel

A model of turbulent transfer that allows for the effect of flow-rate oscillations on the turbulent stress is used to investigate pulsating turbulent flow of a compressible gas in a narrow channel. An algorithm for solving numerically the system of equations that describes this process by the finite-difference method with the use of an implicit iteration scheme is proposed. The effect of operating parameters on the amplitude-frequency characteristic is considered.     

One example of turbulent flow with a strong effect on the pulsation characteristics of the flow

A semiempirical theory of turbulent transfer is used to calculate the flow of a liquid in a tube containing macroscopic formations. The properties of the solution correspond with the data on the effect of polymer additives on the turbulent flow characteristics.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 25, No. 6, pp. 1033–1038, December, 1973.     

Effect of a transverse entrainment flow on the characteristics of a turbulent jet

We have experimentally investigated the influence of a transverse entrainment flow (wind) on the trajectory of a turbulent jet, as well as on the distribution of the concentration of the gas being discharged along that jet (hydrogen, helium, nitrogen). The entraining flow of air is formed in open space. Its trajectory falls out along points corresponding to the maximum concentrations in the lateral cross section of the jet. We have derived empirical relationships between the jet trajectory and the gas-concentration distribution along that trajectory in their dependence on the hydrodynamic parameter.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 59, No. 2, pp. 188–191, August, 1990.     

倾斜热管湍流床的气固流动特性

为了探明间壁式流化床换热器内热管对气固流动状态的影响,采用欧拉双流体模型,并应用能量最小多尺度(energy minimization multi-scale, EMMS)曳力模型,对可实现2种物性相近催化剂热管间壁换热的湍动流化床流动特性进行模拟研究。结果表明:通过与实验数据进行比较,证明模型是有效的;比较热管对床内固含率轴向分布的影响,发现热管的设置可减小气泡尺寸、有效降低颗粒被夹带量;热管对固含率的影响主要位于热管末端,其仅存在于热管所在区域,且随着径向位置靠近隔板逐渐减小;沿热管轴向存在隔板影响区和主换热区,主换热区随着轴向高度的增加而减小,随着表观气速的增大而增大。