Numerical simulation of gas powder flow in laser cladding with coaxial powder feeding

The discrete phase module in FLUENT is used to build the two-dimensional model of gas-powder flow. The impacts of the amounts of shielding gas, transporting gas and fed powder on the concentration field and velocity field distribution, divergence angle and the focus of powder flow are discussed. The calculated results show that with increase in transporting gas flux, the powder velocity increases and the gas-powder flows divergence angle decreases, and with increase in powder feed amount, the gas-powder flows focus moves down a little and the powder concentration at this focus increases. At the same values of the process parameters as in the calculation, the camera is used to take photos of the powder flow distribution. It is shown that the experimental results agree well with the computational results.