Numerical simulation method of powder flow field in laser additive manufacturing coaxial powder feeding nozzle

Abstract

The invention provides a numerical simulation method for the powder flow field of a coaxial powder feeding nozzle for laser additive remanufacturing, and relates to the technical field of laser manufacturing. In this method, the physical parameters of the powder and the material parameters and structural parameters of the coaxial powder feeding nozzle are firstly obtained; then the parameters are calibrated to obtain the simulation experiment parameters, and the three-dimensional calculation model of the coaxial powder feeding nozzle is established according to the structural parameters of the coaxial powder feeding nozzle, and the discrete The powder particle model and the discrete element simulation model of the powder particle motion of the coaxial powder feeding nozzle are established by the element method, and then the gas-powder two-phase model of the coaxial powder feeding nozzle is established by using the computational fluid dynamics method, and then the gas-powder two-phase model of the coaxial powder feeding nozzle is obtained. Powder flow field distribution. The numerical simulation method of the powder flow field of the laser additive remanufacturing coaxial powder feeding nozzle provided by the present invention fully considers the interaction relationship between the gas-powder two phases and the influence of factors such as the physical properties of the discrete phase powder particles on the powder flow field. Therefore, the distribution of the powder flow field of the coaxial powder feeding nozzle can be accurately obtained.

Description

technical field [0001] The invention relates to the technical field of laser manufacturing, in particular to a numerical simulation method for the powder flow field of a coaxial powder feeding nozzle for laser additive remanufacturing. Background technique [0002] Laser additive remanufacturing technology is a surface repair technology that has emerged in recent years. Using this technology to remanufacture and repair failed or misprocessed parts can greatly reduce production costs and has good practical significance. As an important part in the laser additive remanufacturing process, the coaxial powder feeding nozzle guides the powder flow into the laser strong action area and melts the substrate at the same time to form a cladding layer, so its working performance directly affects the forming quality after remanufacturing . At present, the optimal processing technology of laser additive remanufacturing is still based on trial and error experiments, and there is not enoug...

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Problems solved by technology

The Euler-Euler two-fluid model treats the powder flow as a quasi-fluid, does not consider particle-particle, particle-geometry collisions, etc., and ignores most of the physical properties of the particles themselves; while the DPM model is a single-phase coupling, it is the powder A particle is regarded as a particle in space, and only its mass is considered without considering the effect of its own shape and volume on the flow field. In this way, although the change trend of the powder flow field can be roughly obtained through calculation, it cannot accurately describe the powder flow in the flow field. The distribution of the flow field in the actual situation has little guiding effect on improving the powder feeding performance of the coaxial powder feeding nozzle

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