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

Abstract

The invention provides a numerical simulation method of a powder flow field of a coaxial powder feeding nozzle of laser additive re-manufacturing, and relates to the technical field of laser manufacturing. The method comprises the following steps: firstly, obtaining physical powder parameters and material parameters and structural parameters of the coaxial powder feeding nozzle; and secondly, performing parameter calibration to obtain simulation experimental parameters, establishing a three-dimensional calculation model of the coaxial powder feeding nozzle according to the structural parameters of the coaxial powder feeding nozzle, establishing a powder particle model and a discrete element simulation model of powder particle motion of the coaxial powder feeding nozzle by using a discreteelement method, then establishing a gas-powder two-phase model of the coaxial powder feeding nozzle by using a computational fluid mechanics method, and then obtaining a gas-powder flow field distribution condition of the coaxial powder feeding nozzle. According to the numerical simulation method of the powder flow field of the coaxial powder feeding nozzle of laser additive re-manufacturing provided by the invention, the influence of the action relationship between the gas-powder two-phase, the physical properties of the discrete phase powder particles, and other factors on the powder flow field is fully considered, so that the powder flow field distribution condition of the coaxial powder feeding nozzle is 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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