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The relative permeability of oil-water two-phase flow is an important parameter in fractured petroleum reservoirs. It is widely accepted that the sum of relative permeabilities is less than 1. In this study, a series of experiments have been conducted on six rectangular fractures for oil-water two-phase flows. Analytical investigations of the effects of flow rate, aspect ratio, and fracture size on the relative permeability of oil-water two-phase are analysed. Basic fluid flow equations are combined to develop a new analytical model for water-oil two-phase flow in a horizontal fracture. The simulation results predicted by this model are in good agreement with the experimental data. The relative permeability is a function of flow ratio, viscosity ratio, aspect ratio and saturation. It increases as aspect ratio increases if the fracture depths are the same, while it decreases as aspect ratio increases if the fracture widths are identical. Both experiment and model indicate that the sum of relative permeabilities of oil and water is greater than 1 in some cases, different from the accepted view.

To investigate the resistance performance of pore throats in porous media, a new method was used to conduct experiments to indirectly measure the local pressure loss of single-phase water and oil- water two-phase flow through pore-throat structures. Four microchannels were designed and manufactured with MEMS technology. One of the four microchannels is a straight duct with no throat and each of the other three has one throat within the passage. By comparison of total pressure drops between the straight duct with no throat and the channel with a throat at the same flow rate, the local pressure loss over a pore- throat structure can be determined. In this paper, the pore-throat structure is defined as a combination of a contraction, an expansion and a throat to stimulate the pore throat in porous media. Experimental results show that local pressure loss, nonlinear with the flow rate, grows up with the decrease of throat size and the increase of oil volume fraction. Local loss coefficient, characterizing the local resistance performance of pore-throat structure, diminishes with the increase of Reynolds number. Reynolds number (in throat part) is in the range of 100-1100. A new empirical correlation of local loss coefficient is proposed for single-phase water and oil-water two-phase flow through pore-throat structure.

Taking the elevator car bottom structure as the research object, the car bottom sheet metal process structure model was established by the three-dimensional design software SolidWorks. The part connection and support were considered in the simulation, and the mesh division finite element analysis was carried out to study static stress characteristics of the car bottom structure under load. The car bottom structure is optimized by introducing crisscross weldments according to the characteristics. The simulation results show that all the performances are improved, so as to illustrate the effectiveness of structural optimization, which provides theoretical basis for car bottom structure design.

Anthropocentrism of modern society leads to great damage to the environment. Mankind is faced with serious ecological crisis. In order to protect the environment, mankind must abandon political and religious differences and take the road to sustainable development. Modern education as delivering environmental information should contribute to protecting the environment. However, modern education based on utilitarian values can not cultivate global citizen possessing eco-consciousness. Reforming modern education model and advocating ecological education model is a reasonable choice in education reform.