Gas-particle flow code has been develpoed by adding Lagrangian particle tracing technique to the steady/unsteady unstructured adaptive compressible Euler flow code. For steady state calculation, the iterative particle-source-in-cell(PSIC) method is used to couple the gas-phase flow with the source terms evolving with the flow development. Adaptive multigrid method is developed to accelerate the convergence rate of the gas-phase Euler solution before it is let to interact with the droplets via source terms that is evolving in the flow field until a steady state is reached. For transient calculation, new numerical method for the calculation of transient compressible two-phase flow with poly-disperse gas-particle suspension have been develpoed by using the particle adaptation technique.
To verify accuracy of the code, the gas-solid paricle mixture flow in the JPL nozzle is first calculated. Then two-dimensional transonic cascade flow of gas-liquid droplet mixture in the NACA 65410 cascade passage is calculated using the solution-adaptive unstructured grid to estimate the effect of liquid droplets on the aerodynamic performance. The droplet rebound/breakup impact model is also implemented in this code.
The experimental result of Sommerfeld was used to verify accuracy of the transient two-phase flow calculation and investigate the effect of particle adaptation. It is elaborated why the existing numerical solution shows discrepancy from the experimental results of Sommerfeld. It has beenfound that the particle adaptation of the particle control volume is essential to keep the computational accuracy, in case the adaptive grid is used for high resoiution of the shock waves. It is also shown thatcomputation with poly-disoers particle model gives more accurate result than the Lagrangian computation with uniform particle model or Eulerian-Eulerian approach based on the continuum assumption.
