Flow and heat transfer simulation in the ADS Dense Granular-flow Target using the Material Point Method

Abstract

The Dense Granular-flow Target (DGT) proposed by Chinese Academy of Sciences has great potential compared with solid target and liquid metal target. In DGT, the number of metal grains is up to ten million. To study the flow and heat transfer behavior of such a large number of particles, experiments and Discrete Element Method (DEM) simulations are extremely expensive. Therefore, this paper focus on develop a continuum approach suitable for simulating the flow and heat transfer behavior in DGT. This approach is based on the Material Point Method (MPM) and chose the μ(I) rheology as the constitutive model for granular material. It can be concluded from this work that the μ(I) rheology implemented in MPM is able to reproduce quantitatively the granular behavior in hopper flow. The velocity distributions calculated by MPM are in good agreement with those calculated by DEM, although the fluctuation information in particle scale is filtered. The temperature results of MPM are basically consistent with DEM in mesoscopic scale, which is a great improvement compared with the results from uniform velocity estimation. The influences of the effective thermal conductivity, proton current and flow rate on the temperature field are investigated. According to the MPM calculation, the maximum proton current that the target can withstand and the minimum velocity that the granular needs to be met can be estimated quickly. The MPM procedure developed in this paper would be of considerable help in predicting the flow and heat transfer behavior for DGT.