Research on flow field characteristics of compound jet pump
The jet pump is a kind of the mass and energy transportation machine and mixing reaction equipment, which utilizes jet shear and turbulent diffusion. It has simple structure, easy maintenance, good sealing, reliable work and a string of unique advantages because of no moving parts. Jet pump is widely used in mining, geological exploration, deep well water extraction and other many fields. Basing on the mechanism research for jet transmission, a compound jet pump was proposed by combining the central jet and the annular jet. Turbulent numerical simulation was used to study the flow field characteristics of the compound jet pump. The results show that the compound jet structure increases the contact interface between the primary flows and the entrained flow, which contains the cylindrical surface of central jet and the inner cylindrical surface of annular jet. Therefore, the mixing process is accelerated and the effect of mass and energy transfer is improved. In addition, the entrained flow is extracted by the primary flows from the centre and the circumference at the same time, so the extracting capacity of primary flows is enhanced significantly. Compared with the conventional central jet pump and annular jet pump, the calculated peak efficiency of compound jet pump increases by about 10%. The structure has not been greatly changed and the parts increase is little, thus the processing technology for compound jet pump is easy to achieve. The research can provide a scientific basis for the popularization and application of compound jet pump.