This paper presents a \%k\|ε\|k\-p\% multi\|fluid model for simulating confined swirling gas\|solid two phase jet comprised of particle\|laden flow from a center tube and a swirling air stream entering the test secti...This paper presents a \%k\|ε\|k\-p\% multi\|fluid model for simulating confined swirling gas\|solid two phase jet comprised of particle\|laden flow from a center tube and a swirling air stream entering the test section from the coaxial annular. A series of numerical simulations of the two\|phase flow of 30 μm, 45 μm, 60 μm diameter particles respectively yielded results fitting well with published experimental data.展开更多
Electrospinning experiments are performed by using a set of experimental apparatus, a stroboscopic system is adopted for capturing instantaneous images of the cone- jet configuration. The cone and the jet of aqueous s...Electrospinning experiments are performed by using a set of experimental apparatus, a stroboscopic system is adopted for capturing instantaneous images of the cone- jet configuration. The cone and the jet of aqueous solutions of polyethylene oxide （PEO） are formed from an orifice of a capillary tube under the electric field. The viscoelastic con- stitutive relationship of the PEO solution is measured and discussed. The phenomena owing to the jet instability are described, five flow modes and corresponding structures are obtained with variations of the fluid flow rate Q, the electric potential U and the distance h from the orifice of the cap- illary tube to the collector. The flow modes of the cone-jet configuration involves the steady bending mode, the rotat- ing bending mode, the swinging rotating mode, the blurring bending mode and the branching mode. Regimes in the Q-U plane of the flow modes are also obtained. These results may provide the fundamentals to predict the operating conditions expected in practical applications.展开更多
The article used new experimental equipment for effective testing of adhesion coatings on the sheets. Testing was performed in jig by bending roller with selected radius. In the context of experiments a multi-jet syst...The article used new experimental equipment for effective testing of adhesion coatings on the sheets. Testing was performed in jig by bending roller with selected radius. In the context of experiments a multi-jet system was used. The aim of my previous publications and even this article is to achieve that by using of multi-jet plasma system, samples were achieved that will not be damaged coating after the bending. Specific coats on the sheets have been optimized composition of the plasma so that its result was the maximum adhesion of the coating to the steel base of samples. Results of experiments are presented in article. The article focuses on the tensile test and the result of the tensile test. All important values of tensile tests are published in this article. For example: elongation A<sub>50</sub>, A<sub>g</sub>, tensile strength R<sub>m</sub>, and yield strength R<sub>p0.2</sub>. Results with values of tensile tests are also presented in this article. Selected coated steel samples were photographed in the clamped in jig on the tension device. Group selected samples were divided by the applied coating. First, the basecoat, the final coat and coat were treated with a multi-jet plasma system. From a previous publication graphs show the dependence of the strength on elongation of a sample. Further research will be focused on selected coated samples, where samples are etched onto the surface of a network and are bent in a special jig in range bending radius R11 to R35. After bending, the samples are examined at a special optical device and are evaluated deformation circles in straight and bent part of the samples.展开更多
Experimental visualizations and numerical simulations of a horizontal hot water jet entering cold water into a rectangular storage tank are described. Three different temperature differences and their corresponding Re...Experimental visualizations and numerical simulations of a horizontal hot water jet entering cold water into a rectangular storage tank are described. Three different temperature differences and their corresponding Reynolds numbers are considered. Both experimental visualization and numerical computations are carried out for the same flow and thermal conditions. The realizable k-e model is used for modeling the turbulent flow while the buoyancy is modeled using the Boussinesq approximation. Polynomial approximations of the water properties are used to compare with the Boussinesq approximation. Numerical solutions are obtained for unsteady flow while pressure, velocity, temperature and turbulence distributions inside the water tank as well as the Froude number are analyzed. The experimental visualizations are performed at intervals of five seconds for all different cases. The simulated results are compared with the visualized results, and both of them show the stratification phenomena and buoyancy force effects due to temperature difference and density variation. After certain times, depending on the case condition, the flow tends to reach a steady state.展开更多
For the numerical simulation of flow systems with various complex components, the traditional one-dimensional （1D） network method has its comparative advantage in time consuming and the CFD method has its absolute a...For the numerical simulation of flow systems with various complex components, the traditional one-dimensional （1D） network method has its comparative advantage in time consuming and the CFD method has its absolute advantage in the detailed flow capturing. The proper coupling of the advantages of different dimensional methods can strike balance well between time cost and accuracy and then significantly decrease the whole design cycle for the flow systems in modern machines. A novel multi-fidelity coupled simulation method with numerical zooming is developed for flow systems. This method focuses on the integration of one-, two-and three-dimensional codes for various components. Coupled iterative process for the different dimensional simulation cycles of sub-systems is performed until the concerned flow variables of the whole system achieve convergence. Numerical zooming is employed to update boundary data of components with different dimen-sionalities. Based on this method, a highly automatic, multi-discipline computing environment with integrated zooming is developed. The numerical results of Y-Junction and the air system of a jet engine are presented to verify the solution method. They indicate that this type of multi-fidelity simulationmethod can greatly improve the prediction capability for the flow systems.展开更多
文摘This paper presents a \%k\|ε\|k\-p\% multi\|fluid model for simulating confined swirling gas\|solid two phase jet comprised of particle\|laden flow from a center tube and a swirling air stream entering the test section from the coaxial annular. A series of numerical simulations of the two\|phase flow of 30 μm, 45 μm, 60 μm diameter particles respectively yielded results fitting well with published experimental data.
基金supported by the National Natural Science Foundation of China Project (11002139)the China Postdoctoral Science Foundation (20100470854)
文摘Electrospinning experiments are performed by using a set of experimental apparatus, a stroboscopic system is adopted for capturing instantaneous images of the cone- jet configuration. The cone and the jet of aqueous solutions of polyethylene oxide （PEO） are formed from an orifice of a capillary tube under the electric field. The viscoelastic con- stitutive relationship of the PEO solution is measured and discussed. The phenomena owing to the jet instability are described, five flow modes and corresponding structures are obtained with variations of the fluid flow rate Q, the electric potential U and the distance h from the orifice of the cap- illary tube to the collector. The flow modes of the cone-jet configuration involves the steady bending mode, the rotat- ing bending mode, the swinging rotating mode, the blurring bending mode and the branching mode. Regimes in the Q-U plane of the flow modes are also obtained. These results may provide the fundamentals to predict the operating conditions expected in practical applications.
文摘The article used new experimental equipment for effective testing of adhesion coatings on the sheets. Testing was performed in jig by bending roller with selected radius. In the context of experiments a multi-jet system was used. The aim of my previous publications and even this article is to achieve that by using of multi-jet plasma system, samples were achieved that will not be damaged coating after the bending. Specific coats on the sheets have been optimized composition of the plasma so that its result was the maximum adhesion of the coating to the steel base of samples. Results of experiments are presented in article. The article focuses on the tensile test and the result of the tensile test. All important values of tensile tests are published in this article. For example: elongation A<sub>50</sub>, A<sub>g</sub>, tensile strength R<sub>m</sub>, and yield strength R<sub>p0.2</sub>. Results with values of tensile tests are also presented in this article. Selected coated steel samples were photographed in the clamped in jig on the tension device. Group selected samples were divided by the applied coating. First, the basecoat, the final coat and coat were treated with a multi-jet plasma system. From a previous publication graphs show the dependence of the strength on elongation of a sample. Further research will be focused on selected coated samples, where samples are etched onto the surface of a network and are bent in a special jig in range bending radius R11 to R35. After bending, the samples are examined at a special optical device and are evaluated deformation circles in straight and bent part of the samples.
文摘Experimental visualizations and numerical simulations of a horizontal hot water jet entering cold water into a rectangular storage tank are described. Three different temperature differences and their corresponding Reynolds numbers are considered. Both experimental visualization and numerical computations are carried out for the same flow and thermal conditions. The realizable k-e model is used for modeling the turbulent flow while the buoyancy is modeled using the Boussinesq approximation. Polynomial approximations of the water properties are used to compare with the Boussinesq approximation. Numerical solutions are obtained for unsteady flow while pressure, velocity, temperature and turbulence distributions inside the water tank as well as the Froude number are analyzed. The experimental visualizations are performed at intervals of five seconds for all different cases. The simulated results are compared with the visualized results, and both of them show the stratification phenomena and buoyancy force effects due to temperature difference and density variation. After certain times, depending on the case condition, the flow tends to reach a steady state.
基金National Weapon Equipment Pre-research Foundation of China(0C410101110C4101)Innovation Foundation of BUAA for PhD Graduates(YWF-13-A01-15)for funding this work
文摘For the numerical simulation of flow systems with various complex components, the traditional one-dimensional （1D） network method has its comparative advantage in time consuming and the CFD method has its absolute advantage in the detailed flow capturing. The proper coupling of the advantages of different dimensional methods can strike balance well between time cost and accuracy and then significantly decrease the whole design cycle for the flow systems in modern machines. A novel multi-fidelity coupled simulation method with numerical zooming is developed for flow systems. This method focuses on the integration of one-, two-and three-dimensional codes for various components. Coupled iterative process for the different dimensional simulation cycles of sub-systems is performed until the concerned flow variables of the whole system achieve convergence. Numerical zooming is employed to update boundary data of components with different dimen-sionalities. Based on this method, a highly automatic, multi-discipline computing environment with integrated zooming is developed. The numerical results of Y-Junction and the air system of a jet engine are presented to verify the solution method. They indicate that this type of multi-fidelity simulationmethod can greatly improve the prediction capability for the flow systems.
