Dimensionless study on outlet flow characteristics of an air-driven booster

Air-driven boosters are widely used to obtain high-pressure gas. Through analysis of the boosting process of an air-driven booster, the basic mathematical model of working processes can be set up. By selecting the appropriate reference values, the basic mathematical model is transformed to a dimensionless expression. Using MATLAB/Simulink for simulation and studying the booster experimentally, the dimensionless outlet flow characteristics of the booster were obtained and the simulation results agree well with the experimental results. Through analysis, it can be seen that the dimensionless outlet flow of the booster is mainly determined by the dimensionless input pressure of the driving chamber, the dimensionless outlet condition pressure of the booster and the dimensionless area of the piston in the driving chamber. The dimensionless average outlet flow becomes larger with an increasing dimensionless input pressure of the driving chamber, but it becomes smaller with an increase in the dimen- sionless outlet condition pressure of the booster. Especially when the dimensionless outlet condition pressure is approximately 1.4, the dimensionless average outlet flow reaches zero. With an increase in the dimensionless area of the piston in the driving chamber, the dimensionless average outlet flow increases and peaks at approximately 1.89, and after this peak, it starts to decrease. This research can be referred to in the design of air-driven boosters.

Physical and chemical changes of water in the deep interior of the Earth―Decrepitation-style mud-volcano-earthquake―A bright lamp to shed light on the mysteries of the deep interior of the Earth

The 2008-05-12 Wenchuan mud-volcano-earthquake was accompanied with eruption of a huge volume of gas and stone,revealing that earthquakes generally result from instant reverse phase explosion of supercritical water(SCW) at the supercritical point.In the deep parts of the crust and mantle there still exists a large amount of supercritical water equivalent in order of magnitude to that of the Earth's hydrosphere.Soft fluids which exist in the MOHO at the top of the upper mantle are the so-called deep supercritical fluids(SCWD).Supercritical water(SCW) has n×103 times strong capability to dissolve gas.Its viscosity is extremely low and its diffusivity is extremely strong.Therefore,it can naturally migrate toward a region with relatively negative pressure.In the steep break zone of the MOHO at the 57-65 km depth beneath the earthquake belt,due to mutation of overburden pressure,SCWD can automatically separate out CaSiO3 and other inorganic salts,evolving into the SCW(H2O-CO2-CH4O system.In going upwards to the 10-20-km depth of the crust SCW will be accumulated as an earthquake-pregnant reservoir in the broken terrain.The phase-transition heat of SCW is estimated at 606.62 kJ/kg and the reverse phasing kinetic energy is 2350.8 kJ/kg.When automatic exhaust at the time of decompression reaches the critical pressure(Pc),the instant explosion reverse phase will be normal-state air water.It will release a huge volume of energy and high-kinetic-energy gas which has been expanded by a factor of 1000,leading to the breaking of the country rocks overlying the earthquake-pregnant reservoir,thus giving rise to a Ms 8.0 earthquake.As a result,there were formed eruptive and air-driven(pneumatic) debris flows whose volumatric flow rate reaches n×1014 m3/s,and their force greatly exceeds the power of INT explosive of the same equivalent value.