In situ particles deposition imaging in centrifugal fields by implemented SPH-DEM-ANN into linear sensor-type wireless electrical resistance tomography (lsWERT)

In situ particles deposition images in centrifugal fields have been reconstructed by combination of smoothed particle hydrodynamics, discrete element method, and artificial neural network (SPH-DEM-ANN) which are implemented into linear sensor-type wireless electrical resistance tomography (lsWERT). The implemented SPH-DEM-ANN into lsWERT has a training section and a real imaging section. The training section is composed of four components which are 1) calculation component of phase-particles position by SPH-DEM for bead- and liquid-particles position array XP and XL in two-dimensional centrifugal fields, 2) generation component of conductivity map by conductivity map generator for simulated phase-particles array Dsim consisting of element array Γ, node-particles array X^, and phase-particles conductivity array σ, 3) simulation component of normalized resistance by electrical forward problem for simulated normalized resistance array R~sim consisting of simulated resistance array Rsim and simulated reference resistance array Rˇsim, and 4) training component of model factors by ANN for weight factors ki, j and bias βj in hidden layers. After the 4th training component in the training section, the real imaging section reconstructed the in situ particles deposition images in centrifugal fields based on the experimental normalized resistance array R~exp under three bead-particles numbers NP = 40, 48, 56, and four rotational speeds ω =175, 205, 235, and 255 rpm. As the results, the implemented SPH-DEM-ANN into lsWERT is able to reconstruct the in situ particles deposition images accurately with four evaluation indicators which are the averaged difference of phase-particles array between Dsim and Dexp: D¯δ=0.915, the averaged deviation of normalized resistance array between R~exp and R~sim: R¯δ=0.153, the averaged deviation of particles maximum height ZmaxP by a high-speed camera (HSC): Z¯δ=7.18%, and the averaged root mean square error of surface particles deposition quadratic curve: RMSE¯=3.465.