To obtain reasonable scales and grid requirements of computational zone, water flow in 5×5 fuel pins assembly was simulated adopting incompressible N-S equations, standard k-ε turbulent model and SIMPLE algorithm. By comparing pressure drop, velocity and its vertical component at different planes perpendicular to fuel pins, with relative error smaller than 5%, conclusions were obtained. Length of inlet part and outlet part of computational domain should be about 2.0 times and 2.3-2.8 times of space between two spacer. Polyhedral mesh should be adopted and its scale should be smaller than 0.35 mm in zone between spacer as smooth pin zone adopt structured grid with 0.3 mm-0.5 mm dimension.

A fast numerical algorithm for six degrees of freedom electromagnetic probing is proposed, to simulate magnetic field inside a space of 500 mm×500 mm×500 mm. Compared with strict algorithm and current-loop approximation algorithm, normalization computing time ratio is 10⁶:70:1. It shows that the algorithm is feasible and reliable. Finally, how to effectively minimize deviation caused by limited length effect of solenoid coil is discussed to further improve the probing precision and stability of the probing system.

In one- and two- dimensional approximations,the penetration depth-concentration distribution for 200 keV vanadium ions implanted into peanuts is simulated using a Monte Carlo method.The calculation is in good agreement with experimental results.The depth-concentration distribution for nitrogen ions with low energy implanted into peanuts is calculated which can not be obtained with experiment.It provides a computational method for the depth-concentration distribution of ions with low energy implanted into seeds.

To improve the accuracy in the simulation of rotor flowfield and noise in the CFD/Kirchhoff method, a combination of the third-order upwind scheme(MUSCL) and flux-difference splitting scheme, instead of the second-order center-difference scheme which may cause larger wake dissipation, is employed and a N-S solver based upon embedded grids is developed. On the basis of the flowfield solution, a harmonic expansion approach is presented for rotor far-field noise. The approach gives an analytical expression of the integral function in the Kirchhoff formula and thus improves the interpolation efficiency and accuracy. A rotor high-speed impulsive(HSI) noise is calculated and a comparison with available experimental data is made, and good agreement was demonstrated. In addition, the HSI noise of helicopter rotors at different tip Mach numbers and on different observer locations is calculated and analyzed. The calculated results indicate a highly directional nature of the rotor high-speed impulsive noise with a maximum in the plane of rotor, and the impulsive feature of the high-speed noise radiation weakened rapidly with the increase of the directivity angle below the rotor plane.

By using the turbulence model proposed by Dubois & Samain and Lichtenberg, a transport code is presented to simulate a particular sawtooth discharge in T-10 tokamak under Ohmic heating situation. A trigger condition is also coupled into the transport code. The numerical results show that in many respects those with turbulent model agree with the experiment results. In contrast, it was impossible to obtain satisfactory simulations with the reconnection model.

An improved algorithm based on finite element method to calculate the sensitivity distribution of capacitance sensor is presented. By fast generating of global siffness matrix and fast calculating capacitance values, the calculation speed of sensitivity distribution is raised.

The Taylor expansion approximate method is deScribed with the precision of the second order, which is used to solve the electrostatic Poisson equation in the region with arbitrary shape. The Roberta rule is applied to obtain the potential distribution on the axisymmetric axle of the physical problem. A set of universal formulae is derived to solve the problem with various,boundary, so that the complexity of the problem is avoided and the simulating code can be simplied much more.

From the map function of orbit radius, an algorithm is presented for determinating the bounds of the integration in the "Conservation-Map" formulae of charge deposition and the precision of charge deposition, and hence makes the "Conservation-Map" method of charge deposition feasible.

A numerical Program is described. It can display the transport process of ions and the correspond cascade process in solids. It includes principle, physical models, calculation procedure and the range used. A newest nuclear scattering cross-section is used in this program. The Cub-Spline interpolation method is also used in order to raise calculation speed and precision. Some calculation results are given such as the range distribution, energy deposition, radiation damage distribution in semi-infinite medium by included ions with different energy.