Papers by Keyword: Flow Field

Abstract: A mathematical model has been constructed for simulating the RH degasser of an iron and steel Co. Ltd. The flow field of molten steel in the ladle has been investigated; in addition, it is also investigated through physical modeling study. The main objective of the investigation was to assess the influence of gas flow rate and immersion depth on dead zones in the ladle. The results show that the flow pattern of molten steel in RH degasser can be well represented by the mathematical model and the physical model. Except the areas close to the free surface and the zones between the two snorkels and the sidewall in the ladle, these dead zones can be reduced by increasing of gas flow rate and immersion depth. These dead zones were marked with 1, 2, 3, results calculated by mathematical modeling are in good agreement with which obtained by means of physical modeling (water modelling) study increasing of immersion depth could markedly reduce the area of dead zone 3, yet the area of dead zone 1 and 2 could be markedly reduced by increasing the gas flow rate, hence indicate that mixing of dead zones could be intensified through improving gas flow rate and immersion depth.

Abstract: According to the actual operating parameters of tundish in a steel mill, the flow pattern and temperature distribution of molten steel in tundish were studied by CFD and heat transfer calculation method. Changing the height of parapet hole, the effect of parapet hole on flow field and temperature field were simulated. The simulation results show that: the parapet hole height has large influence on flow recirculation position, which can impact surface temperature and outflow temperature of molten steel. When parapet hole height increases, the recirculation vortex moves towards the surface of molten steel in outflow zone, surface temperature rises, but outflow temperature decreases near the narrow wall. Comprehensive analysis show that, when the parapet hole height is 480mm, surface temperature is high, molten steel will not solidify at corner; the reduction of molten steel temperature is small at outflow hole.

Abstract: Air velocity in oven box is an important factor. The value of air velocity will affect the result of drying. This paper use the method of numerical simulation to research the effect of orifice plate on flow field and thermal environment in oven box. The results show the change rate of thermal environment & air flow field in oven box is depend on supply air volume, and the use of orifice plate will affect the flow field obviously.

Abstract: According to the operating parameters of continuous casting tundish in a steel mill, the flow patterns of liquid steel in tundish were studied by the method of numerical simulation. Changing the flow orifice area of slag wall, to simulate and calculate the influence of slag wall on the flow field in tundish. Through calculating the steel flow vector, to analyze the uniformity of steel flow in tundish, by calculating the inclusions distribution to analyze the effect of blocking slag wall holding inclusions. The simulation results show that: the slag wall can obviously deduce the short circuit flow of steel liquid in tundish bottom. With the flow orifice area is reduced, and the turbulence brisk between two slag walls, and liquid surface is easy to roll; the ability of slag wall holding inclusions enhances, but too small flow orifice area will prompt inclusions passing the slag wall.

Abstract: Researches on vibration of centrifugal pump induced by fluid exciting forces are significant for reducing equipment faults, which are caused by the vibration transferring from the base, and noise emission of shells which connected with the base. Fluid exciting forces are the main vibration sources in centrifugal pump systems. The vibration of impellers is generated by fluid exciting forces, and transferred to mechanical systems through pump shell and shaft bearings. By optimizing of inner flow filed of centrifugal pump, not only the fluid exciting forces can be reduced, but also the vibration level of the pump can be improved. In this paper, based on reducing noise and isolating vibration, the inner flow field of the centrifugal pump was emulated by CFD method. The flow field was optimized by controlling the impellers cutting process. The optimizing results were shown by comparing the pressure pulsation of the optimized flow field with those of the original flow field. The improvement of optimization was verification by measuring the vibration responses of the centrifugal pump base structure. The experimental results shows that: the level of flow field excitation and the pressure pulsation of flow field under the blade frequencies and multiplication frequencies are declined to some degree by cutting impellers; the vibration responses of pump base decreased 4.5 dB after cutting impeller.

Abstract: The erosion and wear mechanism for drilling equipment is studied in this paper, which is for the problem of unstable performance of drilling system and short lifetime caused by the erosion of drilling equipment by drilling fluid. The flow field, surface pressure of the erosion prone parts and drilling fluid flow rate are calculated by the finite element method. The results demonstrate the parts eroded seriously by drilling fluid appear in where the curvature of the curve of the wall changes suddenly and where the rate of change in the stress field is greater, which provide a theoretical basis on design, optimize, repair of drilling equipment.

Abstract: This paper focus on the detailed influence of forward-facing cavity on the opposing jet. The flow field of a hemisphere nose-tip with the combined configuration was simulated numerically and the surface heat flux distribution was obtained. The numerical results show that a suitable cavity is helpful for the opposing jet. With the same total pressure, the single opposing jet even can’t form a stable flow field and there is no cooling effect.

Abstract: The key of swirling airflow finishing is how to generate the swirling airflow. In the paper, three swirling airflow head are discussed according the manners of tangential inflow. By means of FLUENT, the general software of CFD, the swirling airflow field from different airflow head is simulated. The simulation results are shown by the flow line graphs, tangential velocity, radial distribution graphs, etc. All we have studied is as the basis for the determination of the application scope of each swirling airflow head.

Abstract: Electrical vehicle (hereafter EV) controller has proper function under the circumstances of interval thermal field due to controller sensitivity; therefore flow field and thermal field are key performance of controller application. Methodology is discussed; optimal flow field and thermal field are determined by use CFD simulation, battery frame material is confirmed as well.

Abstract: In this paper, using the finite element software of ADINA to analyze and simulate the meshing rotor element of the double rotor in the block rubber continuous mixer in the computer, the paragraphs games pressure, viscosity, shear stress field are analyzed. Through simulation analysis we found that mesh mixing rotor element type in rubber mixing process has strong shear, tensile, compression, stirring, mixing and the axial reciprocating cutting action on the rubber, realize the better dispersion and distribution mixing all kinds of material, reached good mixing effect. Rubber mixing rotor continuous component of three dimensional flow field’s simulation provides reliable theoretical basis and technical parameters for optimal design of rubber mixing rotor.