An Experimental Study on the Following Behaviors of Near-Wall Fine Particles in Turbulent Tube Flow

In severe accident of nuclear plant, many non-or radioactive line particles are mainly PM₁₀ (Particulate Matter10). Studying the PM₁₀ thermophoretic deposition model can provide a theoretical basis for the design of advanced reactor. In this study, the diversification law of fine particles near-wall velocity in the temperature field of rectangular channel is studied using the two-phase experimental system of gas-particle and a PDA method (Particle dynamic analyzer of three-dimension laser) to effectively measure the diversification law of fine particles near wall velocity. Based on the experimental data, the variations of the following behaviors of particles with different diameters in the temperature field are calculated and analyzed. At the same temperature ratio, the velocity of the fine particles decrease with increased diameter, and the following behaviors decrease. Under the identical temperature ratio, the fluctuation of the particle velocity increases with decreased diameter. The velocity variation of the fine particle increases with increased temperature ratio in the boundary layer. The fine particles are easily deposited by the high temperature ratio of the particles and the wall, and the following behaviors of the particles with larger diameter decrease. The fine particles are forced by the flow thermophoretic force. The concept of flow thermophoretic force to the flow direction is brought to explain the velocity of fine particles in high temperature field.