Numerical analysis of internal flow of abrasive entrained waterjet nozzle
LONG Xinping1,2, LIU Qi1,2, RUAN Xiaofeng1,2, CHEN Zhengwen3, XUE Shengxiong3, WU ziquan4
1.School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei 430072, China; 2.Key Lab of Hubei Province oratory Waterjet for Theory and New Technology, Wuhan, Hubei 430072, China; 3.Hefei General Machinery Research Institute, Hefei, Anhui 230031, China; 4.Shenyang All-Powerful Science and Technology Stock Co.Ltd., Shenyang, Liaoning 110179, China
Abstract：Abrasive entrained waterjet nozzle is a core component of high-pressure abrasive waterjet equipment. In order to investigate the internal flow and particle movement in the nozzle, numerical simulation of the multiphase flow in the nozzle was conducted based upon the Euler-Lagrange approach, and Discrete Particle Method was adopted to calculate the trajectories of abrasive particles by taking the shape factor of particles and the energy loss due to the collision with the wall into consideration. The results indicate that the air phase near the entrance of focusing tube has a comparatively large tangential velocity which will drag the particles to conduct circumferential movement, and the resulting centrifugal force will enhance the possibility of the collision of the particles with the local wall which can enhance the erosion in this area. A longer focusing tube will contribute to the dissipation of the circumferential movement and guarantee the particles ejecting from focusing tube without large tangential velocity. The decease of particle shape factor will enhance the acceleration of abrasive particles. The particle inlet velocity has little impact on the particle outlet velocity in the current nozzle model. The results are of importance to gaining a deep insight of the nozzle internal flow and nozzle optimization.
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