Study Of FDTD Parallel Computing And ADI-FDTD Method

Based on a spatial decomposition of the regular grid structure, the FDTD computation space is divided into some sub-domains. Then the fields inside each sub-domain are computed on an individual processor with a small amount of data being communicated from neighboring sub-domains. According to the characteristic of FDTD computation formulas, there is an overlapping region between adjacent sub-domains, so that data communication is needed. The partition for 3D FDTD domain is the same as the one made for 2D FDTD domain. The identifier for each sub-domain is defined as the three-dimensional spatial location in the entire simulation domain. Some synchronization to be performed in all processes is required. Two main pathways that are use of blocking messages and use of barriers can be pursued to achieve the goal. It is worth noting that the domain partition leads to increased complexity in programming while the absorbing boundary, total-field scattered-field boundary and near-to-far field extrapolation boundary are located in different sub-domains.A parallel algorithm for the FDTD method on a distributed network by using the message-passing module is presented. The parallel platform of PVM system is applied to the implementation of FDTD parallel algorithm. The structure of the parallel program adopts a master-slave organization. Then the parallel program is divided into two parts of master program and slave program. The functions of the master program mainly include the creation of process, the initialization of iterative, the collection and display of the computation results, and so on. Similarly, the functions of the slave program mainly include the execution of FDTD computation, and the load of slave process is distributed by master process. Finally, flow diagrams of the parallel FDTD program are given, and the concrete functions of each module are discussed in detail.The EM scattering problems of 2D and 3D objects are analyzed by using the parallel FDTD method. The radar cross sections (RCS) of complex objects of metallic wing and NASA almond and practical object of missile are presented. In order to exactly imitate the contour of the missile warhead in the FDTD modeling, the superspheroid body is successfully applied. Then, the coefficient design of the superspheroidal equation, which can be modeling a number of shapes, such as Von Karman radome available for missile warhead is discussed. The calculated results of the back scattering demonstrate that the...