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Performances of vanes with various numbers and front oriented-body with different shapes such as half sphere, half ellipsoid and cone are simulated by RNG κ-ε model and standard wall functions method in order to optimize the parameters of the front oriented-body attached on the new bidirectional flowmeter. The performances of weakening-vortex and the pressure losses attaching to various models are analyzed and compared with each other. The results show that the structure with cone guide-head and 6 vanes can obtain the minimum range of flow pulsation, the least pressure loss and the least reverse flow. The simulation methods and results will be used for reference to analyze the similar annular flow and design the steady device.

The configuration of a new swirlmeter is designed. The hollow cylindric fluid axial-symmetrically in cylindric pipe is analyzed, and then the algebra expression of meter coefficient is deduced. An impeller of swirl generator attaching to a specimen of swirlmeter is designed according to the deducing process. Simulations and experiments test the method of measuring flowrate by measuring the rotation frequency of ball is feasible. Comparing the results of simulations and experiments with that of algebra expression derived from deducing in theory the maximal error is 7.8%. At last, the reasons resulting in the errors are discussed which the next researches will continue to minus the errors. The conclusion will be applied in designing the impeller of swirl generator and measuring the flow by the new swirlmeter.

To ensure the security and integrity of three dimensional point clouds model during transmission in the network, according to their own characteristics, after the pretreatment of PCA (Primary Component Analysis), three dimensional point clouds watermarking embedding algorithm based on sphere degenerated octree was proposed, and the octree that contained the original point clouds model was subdivided multilevel from top to bottom, and the nodes of the octree were ordered. And three dimensional point clouds watermarking extraction algorithm was proposed, and the original point clouds model and the watermarked model were registered accurately, and the occurrence of synchronization error was avoided. Experimental results showed that the presented algorithm was robust to many attacks such as rotation, translation, uniform scaling, vertices reordering, simplifying, noise and cropping under blind detection.

The accuracy and efficiency of finite element analysis is closely related to mesh quality. There is a lack of universal automatic meshing method currently. Existing hexahedral meshing methods suffer from poor meshing compatibility between different geometric constraints and poor meshing quality, especially for complex models with varieties of geometric features. To solve this problem, a novel hexahedral meshing method based on the mapping algorithm for multi-featured geometry is proposed. In this method, the model boundary is extracted and converted into regular shape, subdomain constraints generated by different geometric feature are projected to one face for centralization, the dividing number of boundary edges are comprehensive computed to make mapping mesh compatible between subdomains, and then dividing lines are generated by linking appropriate nodes on the subdomain boundary and the nodes on the face boundary with consideration about dividing result. Finally, high quality structured mesh is filled in the divided patches and then mapped back to the original model to finish hexahedral mesh generation. Examples demonstrate that the proposed method is reliable and robust, and can handle the hexahedral mesh generation of complex geometries with multi-features.