Numerical analysis of lost foam casting for large-caliber water meter shell

Large-caliber water meter shells are prone to shrinkage porosity, wrinkles, air entrapment, slag inclusion, and other defects during the lost foam casting process. Taking the vertical spiral wing WS-100 water meter as the research object, through the analysis of the structure of the water meter shell, the flow field and temperature field of the design of outer bottom injection-vertical pouring, outer bottom injection-horizontal pouring and inner bottom injection-horizontal pouring involved in the filling and solidification process are numerically simulated and solve analysis, respectively. The results showed that: when the inner bottom injection-horizontal pouring process was adopted, the filling process of the casting was stable, the isolated liquid phase area of the solidification process was relatively small, and the possibility of forming defects was less. The casting performance is excellent, and the numerical analysis is verified to be effective.

Changes of Multiphase Flow Patterns during Steel Tapping with Simultaneous Argon Bottom Stirring in the Ladle

Changes of unsteady multiphase fluid flow patterns of liquid steel during electric arc furnace-ladle tapping operations, with simultaneous argon bottom injection, are simulated using interfacial tracking computing techniques. The impinging steel jet interacts with the argon bubbling plume, suffering mutual bending effects, and imparting non-symmetric flows of liquid steel during the whole ladle filling time. At low bath levels, radial recirculating flows are generated and at high bath levels, these flows are substituted by vertical long flows generated by the permanent interaction between the impinging jet and the argon plume. Turbulence intensity increases as the bath level rises. Low bath levels are suitable for pre-melting and preheating ferroalloy particles. High bath levels of steel in the ladle, close to total ladle filling, are the most suitable conditions for thermal and chemical homogenizations. Argon gas forms an intermittent blanket over the air–liquid steel mix due to its higher density than air during the whole ladle filling time.

Experimental Investigation of a Two-Phase Drainage Process in Porous Media

This paper presents an experimental study of two phase water-oil displacement in transparent porous media model made of mini-channels. The working fluid (water or/and oil) was injected into the porous matrix using a syringe pump with a constant flow rate. The influence of gravity and flow rates were studied. The volume fraction was defined and measured during the drainage. Two different experimental configurations, namely vertical and horizontal mini-channel were studied. For the vertical mini-channel, two injections, namely gravity-assisted (top-to-bottom) injection and anti-gravity (bottom-to-top) injection were performed. Experiments using horizontal mini-channel were also performed with the inlet and outlet placed on the same horizontal plane. It was observed that the gravity has significant effect in case of gravity-assisted injection and did not influence the anti-gravity injection or the horizontal injection setups.

CO2 Injection in Vertical and Horizontal Cores: Measurements and Numerical Simulation

Summary In certain high-pressure and low-temperature reservoirs, the density of CO2 may be substantially higher than the oil density. Upon mixing of CO2 and oil, a gas phase with a high content of methane (C1) may also appear. When the C1 content is high, this gas phase may have a lower density than the oil. In relation to this phenomenon, we have conducted three comprehensive experiments studying CO2 injection from the top and bottom of a vertical core and injection in a horizontal core. The injection rate is 1 PV/day. This low rate allows the study of diffusion. The core diameter used in this work is 3.8 cm and the length is 27.3 cm. The tests are conducted at a pressure of 441 bar and a temperature of 60°C. At 2.6 hydrocarbon pore volume injection (PVI), the coreflood results give a recovery of 98% for bottom injection, 84% for top injection, and 92% for horizontal injection. We have also conducted an extensive set of measurements to determine swelling, viscosity, and density for the calibration of an equation of state. We simulate the experiments using a state-of-the-art higher-order finite-element three-phase compositional model. The simulations suggest that the endpoint relative permeability of the CO2-rich phase may be lower than the oil phase. The results also show that Fickian diffusion should be taken into account, but that the diffusion coefficients are reduced, because the CO2/oil mixtures are in the near-critical region for much of the injection. Even for a horizontal core there is a considerable gravity effect. One main conclusion is that there may be vast differences between CO2 injection in a 1D slim tube and in a core where there may be a 2D flow. A related conclusion is that analysis of CO2 coreflooding may provide important parameters for field-scale problems.

Study on Distribution of TiC Particles in Molten Steel under Electromagnetic Stirring Condition

This paper explored the distribution regularities of TiC particles in molten steel under electromagnetic stirring condition. The influencing factors on distribution such as the unit stirring power(P), the styles of TiC particles addition and the methods of surface pretreatment had been studied in our experiments. The results show that it’s easier to get uniform distribution by the way of high-power smelting with miniwatt stirring and the bottom injection. Besides, the pretreatment plays an important role in particles distribution.