A BNCT treating planning system MCDB is developed.Three-dimensional material matrix and tally matrix are designed, which are used to describe voxel models and tally.A fast track technique is used in simulation.Computation time is greatly decreased compared with MCNP code.Same dosimetry results with MCNP are achieved by MCDB,which is faster by 3.1-3.4 times with respect to MCNP.Computation time and accuracy of most voxels reach clinical BNCT requirement in a scale of 10 million particles.

A joint-scalar probability density function (PDF) method, a steady laminar flamelet model, a Eulerian unsteady laminar flamelet model and a hybrid RANS and PDF method are employed in calculating a bluff-body stabilized turbulent non-premixed Sydney flame HM1. Nitrogen oxides emission is numerically simulated with the joint-scalar PDF method and the Eulerian unsteady laminar flamelet model in order to investigate influence of combustion models on the formation of nitrogen oxides. Comparisons between numerical results and experimental data show that chemical reactions by PDF are best while the computational cost is expensive. The laminar flamelet model results shows lower computational cost and are reasonable in complete combustion.

A joint-scalar probability density function (PDF) model is used to simulate bluff-body stabilized turbulent non-premixed Sydney flames HM1. In Situ Adaptive Tabulation (ISAT) algorithm is used to accelerate chemistry calculations. A modified LRR-IP Reynolds stress model is applied to obtain mean flow and turbulent mixing fields. We consider three chemical kinetical schemes for methane chemistry. Simulation results are compared with experimental data. It shows that the model and mechanisms predict flow field, scalar field and local extinction well. C2 chemistry has minor effect on flame HM1.

Gas filtration combustion in porous media differs substantially from the combustion with free flame. A one-dimensional model is proposed, and a perturbation theory is used for the combustion front velocity analysis of the methane-air premixed combustion in an inert packed bed, The temperature distribution is predicted for either fully-developed or transient combustion state, based on direct solution and Green's function method. Finally, computational experiments are given and the results are satisfactory.