Numerical Simulation And Experimental Research On The Internal Flow Field Of Rotating Variable Diameter Pipe

The rotating variable diameter pipe is one of the important equipment for water treatment,its prototype is hydrocyclone.Complicated physical mechanism of turbulent flow about shear helical flow is contained in the Internal Flow Field,it is used in the field of engineering.Such as oil field wastewater treatment,the dehydration of crude oil in the field.However,the research for complicated movement wall turbulence is very short,the regularities of distribution of internal flow field in the rotating variable diameter pipe is not clear completely,there isn't a turbulence model which can simulate the internal flow field in the rotating variable diameter pipe clearly.The character of rotating turbulence is combined and the rapid distortion theory is used to establish the amended SSG model,the regularities of distribution of flow field in the rotating variable diameter pipe is got by simulating the flow with the new model.The theoretical direction and reference model is provided for the complex turbulence practical engineering application witch represented by the hydrocyclones.The rotating invarible diameter pipes are simulated by adding higher order term ?ij(r?)witch contains large scale quantity ?ij to Stress and strain term ?ij(r)which is amended SSG model.The developmental tendency of rotating invarible pipe turbulence which from initial anisotropy to isotropy can be reflected better by the new model.The amend SSG model is proved correctly to simulate the rotating pipes turbulence.The varible diameter pipe is simulated by the amended SSG model,the axial velocity,tangential velocity,turbulence intensity,turbulence dissipation rating and static pressure parameters were got in the different sections in different rotating speeds,the character curves were analyzed,the tangential velocity is enhanced when the wall rotateing along the forward direction and the tangential velocity is restrained when the wall rotateing along the reversed direction.The axial velocity is enhanced in the rigidity vortex and the axial velocity is restrained in the free vortex when the wall rotateing along the forward direction.The opposite results can be got when wall rotateing along the reversed direction.At the same time,the turbulence intensity,the turbulence dissipation rating,static pressure were different when the wall rotating.The experiment table with the rotating variable pipe is designed to measure the tangential velocity and the axial velocity when the wall rotating,and the simulating results with amended SSG model were compared with the experimental results,in the end,the simulation results is identical with the experimental results.In conclusion,the amended SSG model is established by combining theoretical research,numerical simulation and experiment,the simulation results were proved to be true by compared with the experimental results,the internal flow field of rotating variable diameter pipe which is more precise is provided,turbulence modeling and numerical modeling references were provided for rotating pipe flow research.