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In order to research the evolution of permeability and damage of fractal rock under hydraulic fracturing, a new damage variable that describing relative reduction of pore amounts as radius is bigger than r any fracturing stage is defined. Assuming the process of evolution of micro-fracturing is in accord with standard model of Logistic bifurcation theory, according to energy conservation principle,...
Based on analysis of hydrostatic bearing with circular pocket, equations of static pressure, volvme pressure and squeezing pressure which influence dynamic characteristics of hydrostatic guides with rectangle pocket have been deduced. The function and their influencing factors of the three kinds pressure mentioned above are clarified. The amplitude-phase-frequency characteristics of the hydrostatic...
A test platform based on hydro-pneumatic suspension was set up to research the pressure characteristic of damping hole of this kind suspension. A series of experiments on damping holes of different diameters were carried out, and the pressure on both sides of damping holes were recorded. A mathematical model of this platform was established using knowledge of fluid mechanics; various parameters of...
Design calculation of gearbox torque will improve a pumping unit's efficiency. The kinematic relation and total loads of polished rod were developed based on the kinematic and dynamic analysis of the pumping system. The method combined the counterbalance effect with the calculated dynamometer cards and torque factors to compute the net gearbox torque. The results show that the dynamic load is relatively...
A modern methodology is presented for the optimum design of sucker rod pumping system. The pump setting depth and rod string tapers were determined for any production rate by an iteration algorithm. The optimization criterion was proposed to select the optimum pumping mode from the combinations of pumping parameters. The results show that size of pumping unit, plunger size, stroke length, pumping...
The tribological properties of nano-Cu lubricating additives and electroless deposited Ni-W-P coating as well as their synergistic effect are researched using ring-block abrasion testing machine and Energy Dispersive Spectrometer. Research results show that the wear resistance of Ni-W-P alloy coating after heat treatment at 400°C has greatly increased since the Second Phase Ni3P particles were educed...
This article introduces some principal parameters, which are required to be monitored, of machine electric spindle, hardware components of the system and main functions of configuration software MCGS(Monitor and Control Generated System) in China. The system is a set of online monitoring and analysis system that is designed for machine electric spindle. The system analyzes real-time information acquired...
This paper discusses the spray characteristics of a new generation multi-hole injector for spark-ignition gasoline engines with direct fuel injection (DISI) and homogeneous combustion system. In order to satisfy the design request of combustion system, numerical simulates the liquid spray progress using currency commences star-cd code. In the work, the injection pulse rule is kept almost constant...
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