The study of bed-load transport is of great significance both in theory and in practice.This paper discusses the saltation of bed-load solid grains in flowing water.Experiments and theoretic analysis have been made by...The study of bed-load transport is of great significance both in theory and in practice.This paper discusses the saltation of bed-load solid grains in flowing water.Experiments and theoretic analysis have been made by means of high-speed photographing and advanced data processing technique with a combined method based on mechanical and statistical theories.It indicates that the saltation is the main form of the bed-load transport under ordinary flowing conditions.In the meantime,taking suecessive saltation as the mod- el of bed-load transport,systematic analysis has been made with regard to the kinematic properties and mechanism of saltation.The statistical analysis shows that the probability density functions of the relative height and length of saltation are in conformity with Γ-type distribution,while the probability density func- tions of the relative velocities of saltation are in conformity with the Gaussian distribution.展开更多
The finite analytic method (FA) developed in the last decade is an effective numerical method for solving fluid flow problems. However, because of the limitation in the present computer, large round-off errors are fou...The finite analytic method (FA) developed in the last decade is an effective numerical method for solving fluid flow problems. However, because of the limitation in the present computer, large round-off errors are found in calculating FA coefficients when Reynolds number is large. This paper investigates the cause of this difficulty and presents a special programming technique in making an accurate computation of FA coefficients. Then a fundamental function known as 'Pe' is tabulated by the accurate computation. In practical application the interpolation technique is employed so that the FA coefficients can be obtained reliably and quickly.展开更多
Taking refined forecasting model of oil pollution as basic target,this pa-per widely deals with the theory and method of refined simulation of turbulent two-phaseflow.The two-fluid model of turbulent buoyant recircula...Taking refined forecasting model of oil pollution as basic target,this pa-per widely deals with the theory and method of refined simulation of turbulent two-phaseflow.The two-fluid model of turbulent buoyant recirculating two-phase flow and the cor-responding method of numerical computation are developed in this paper.The motion ofeach phase is described by a unified multi-fluid model in an Eulerian coordinate system.The laws of turbulent transportation for each phase,and the restriction of each other be-tween the two phases are completely simulated.The complex two-phase turbulence withbuoyancy and recirculating flow is selected to examine numerically.Comparison of the re-sults of numerical simulation with the experimental data is conducted.Then the forecastsfor oil-water two-phase turbulence are carried out.It has been shown that the results ofnumerical simulation are satisfactory.展开更多
基金The project supported by National Natural Science Foundation of China
文摘The study of bed-load transport is of great significance both in theory and in practice.This paper discusses the saltation of bed-load solid grains in flowing water.Experiments and theoretic analysis have been made by means of high-speed photographing and advanced data processing technique with a combined method based on mechanical and statistical theories.It indicates that the saltation is the main form of the bed-load transport under ordinary flowing conditions.In the meantime,taking suecessive saltation as the mod- el of bed-load transport,systematic analysis has been made with regard to the kinematic properties and mechanism of saltation.The statistical analysis shows that the probability density functions of the relative height and length of saltation are in conformity with Γ-type distribution,while the probability density func- tions of the relative velocities of saltation are in conformity with the Gaussian distribution.
文摘The finite analytic method (FA) developed in the last decade is an effective numerical method for solving fluid flow problems. However, because of the limitation in the present computer, large round-off errors are found in calculating FA coefficients when Reynolds number is large. This paper investigates the cause of this difficulty and presents a special programming technique in making an accurate computation of FA coefficients. Then a fundamental function known as 'Pe' is tabulated by the accurate computation. In practical application the interpolation technique is employed so that the FA coefficients can be obtained reliably and quickly.
基金Project supported by the National Natural Science Foundation of China.
文摘Taking refined forecasting model of oil pollution as basic target,this pa-per widely deals with the theory and method of refined simulation of turbulent two-phaseflow.The two-fluid model of turbulent buoyant recirculating two-phase flow and the cor-responding method of numerical computation are developed in this paper.The motion ofeach phase is described by a unified multi-fluid model in an Eulerian coordinate system.The laws of turbulent transportation for each phase,and the restriction of each other be-tween the two phases are completely simulated.The complex two-phase turbulence withbuoyancy and recirculating flow is selected to examine numerically.Comparison of the re-sults of numerical simulation with the experimental data is conducted.Then the forecastsfor oil-water two-phase turbulence are carried out.It has been shown that the results ofnumerical simulation are satisfactory.
