Study on boundary characteristics of meshless particle method

The existence of discrepancy between the discretized numerical boundary of meshless particle method and the assumed real one is proved by the mechanism analysis based on the notion of particle number density. By simulating the movement of scattered fluid particles in the vicinity of boundaries under typical cases and analyzing their trajectories, such difference is verified. What's more, the way of the boundaries exert influences on flows and its related phenomena are conspicuously demonstrated. The results show that the numerical boundaries do not exactly represents the real physical ones and their influences zone to fluid are not smooth, which lead to deflect and error for the near wall flows, especially for the scattered fluid particles with low velocity.