The Horizontal Axis Of The Spiral Hydraulic Characteristics And Solid Particles Suspended Mechanism Pilot Study

Sediment transportation in spiral pipe flow is a new method of sediment trans-portation. In this paper, the generating ways and hydraulic characteristics of spiralpipe flow, and the suspended Mechanics of particle in forced vortex with horizontalaxis were investigated by use of theory analysis and laboratory tests.1. Investigation on the generating ways of spiral flow in pipe. In this paper, thespiral flow generator- generating spiral flow by a part of pipe was investigated.The main conclusions are as follows. The structure parameters of the spiral flowgenerator have important influence on generation of the spiral flow in pipe, which in-clude its diameter and length, the .number and height and setting angle of guideblade. The cross-section axial velocity distribution at outlet of the spiral flow gen-erator is a logarithm-like function and more uniform than that of 2-D pipe flow.The outlet cross-section circumfential velocity distribution of the spiral flow gener-ator is a linear function. Its outlet cross -section rotational angular velocity growswith the increase of the discharge and is related to the structure parameters of spiralflow generator. The outlet cross -section pressure distribution is paraboloid of revo-lution and is directly proportional to the square of the rotational angular velocity, itis maximum near to the pipe wall and minimum at the pipe center.2. Study on the resistance characteristics and rotation efficiency. The main con-clusions are as follows. When water flows through the spiral flow generator, itspressure head loss consists of its resistance loss and the outlet cross -section rota-tion kinetic energy. The resistance loss formula of spiral flow generator was de-duced. The formula type is in accordance with Darcy's equation but the resistancecoefficient λq and in the formula is different from Darcy's resistance coefficient λ becauseλq concludes λand the structure parameters of the spiral flow generator. The coeffi-cient λq equates to λ when there is no guide blade in spiral flow generator. The rota-tion efficiency of the spiral flow generator can be risen, if the resistance loss is re-duced and the rotational angular velocity of flow is increased.3. Investigation for the hydraulic characteristics of the spiral flow in circle pipewith horizontal axis. The main conclusions are as follows. The cross -section axisvelocity distribution of the spiral pipe flow with horizontal axis is also a logarithm-like function, but its uniform degree is between that of the outlet cross-section ofthe spiral flow generator and 2-D pipe flow. If some cross-section is farther fromthe outlet cross -section of the spiral flow generator, the uniform degree of its axialvelocity distribution is closer to that of 2-D pipe flow. The circumferential velocitydistribution in the cross-section of the spiral pipe flow with horizontal akis is a linerfunction and its cross-section rotational angular velocity is negative exponent func-tion of axial locatin. The head loss between 2 crosss-ections is equal to the differ-ence of piezometric head of pipe wall at 2 cross-sections and is equal to the sum ofaxial and circumferential head loss. The energy grade and length of spiral pipe flowwith horizontal axis were also discussed in this paper.4. Study on the suspension mechanics of particle in spiral pipe flow with hori-zontal axis. the main conclusions are as follows. The suspension standard of particleis that particle arises and is located at the horizontal diameter of pipe cross -sectionby the action of circumferential flow. The relationship between rotational flow con-dition and tractive height, and the flow condition in which particle gets into suspen-sion state were expressed by use of mechanics analysis. The particle suspension me-chanics in spiral pipe flow with horisontal axis and the special action on particle sus-pension motion of circumferential flow were discussed.5. Investiga...