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851.
非结构化网格浸入边界法的流固耦合数值模拟(英文) 总被引:1,自引:0,他引:1
This paper presents an improved unstructured grid immersed boundary method. The advantages of both immersed boundary method
and body fitted grids which are generated by unstructured grid technology are used to enhance the computation efficiency of
fluid structure interaction in complex domain. The Navier-Stokes equation was discretized spacially with collocated finite
volume method and Euler implicit method in time domain. The rigid body motion was simulated by immersed boundary method in
which the fluid and rigid body interface interaction was dealt with VOS (volume of solid) method. A new VOS calculation method
based on graph was presented in which both immersed boundary points and cross points were collected in arbitrary order to
form a graph. The method is verified with flow past oscillating cylinder. 相似文献
852.
实际海浪环境大尺度模型试验遥控遥测系统(英文) 总被引:1,自引:0,他引:1
Physical testing of large-scale ship models at sea is a new experimental method. It is a cheap and reliable way to research
the environment adaptability of a ship in complex and extreme wave conditions. It is necessary to have a stable experimental
system for the test. Since the experimental area is large, a remote control system and a telemetry system are essential, and
were designed by the authors. An experiment was conducted on the Songhuajiang River to test the systems. The relationship
between the model’s speed and its electromotor’s revolutions was also measured during the model test. The results showed that
the two systems make it possible to carry out large-scale model tests at sea. 相似文献
853.
Sandwich plate systems (SPS) are advanced materials that have begun to receive extensive attention in naval architecture and
ocean engineering. At present, according to the rules of classification societies, a mixture of shell and solid elements are
required to simulate an SPS. Based on the principle of stiffness decomposition, a new numerical simulation method for shell
elements was proposed. In accordance with the principle of stiffness decomposition, the total stiffness can be decomposed
into the bending stiffness and shear stiffness. Displacement and stress response related to bending stiffness was calculated
with the laminated shell element. Displacement and stress response due to shear was calculated by use of a computational code
write by FORTRAN language. Then the total displacement and stress response for the SPS was obtained by adding together these
two parts of total displacement and stress. Finally, a rectangular SPS plate and a double-bottom structure were used for a
simulation. The results show that the deflection simulated by the elements proposed in the paper is larger than the same simulated
by solid elements and the analytical solution according to Hoff theory and approximate to the same simulated by the mixture
of shell-solid elements, and the stress simulated by the elements proposed in the paper is approximate to the other simulating
methods. So compared with calculations based on a mixture of shell and solid elements, the numerical simulation method given
in the paper is more efficient and easier to do. 相似文献
854.
Experiments were conducted to study characteristics of flow when flow is fluctuating. The experimental results showed a phase
difference between the flow rate and the pressure drop fluctuations. This phase difference between the fluctuating flow rate
and pressure drop was analyzed for laminar flow. Analysis showed that the phase difference changes with the period of the
flow fluctuation, the pipe radius, the density and the dynamic viscosity of the liquid. Fluctuating pipe flow was then numerically
simulated. Results of the numerical simulation were compared with theoretical values and experimental results. It was shown
that, when the flow rate fluctuates with time as a sine wave, the pressure drop fluctuates with the same periodicity, and
there is a phase difference between them. 相似文献
855.
为护航"畅通高效平安绿色的低碳交通——内河航运",广东海事局十年来在珠江口着力打造了一条"水上高速航路",这是3月16日记者从广东海事局在广州召开的新修订《珠江口水域船舶安全航行规定》(以下简称《规定》)宣贯会上获悉的。据了解,经修订的《规定》针对珠江口水域通航环境的变化情况和存在问题,进行了科学合理的规定,内容更加简明,方便广大船员理解掌握。 相似文献
856.
857.
858.
上海某大桥主桥为双塔自锚式悬索桥,主体结构采用(40+70+40)m三跨塔梁组合结构体系,由钢筋混凝土主塔、预应力混凝土箱梁、主缆、吊杆组成。本文主要针对主缆混凝土浇筑对预应力管道破坏的施工问题进行分析,从施工过程记录、预应力孔道变形参数汇总分析、后续解决流程及方案三方面综合分析,全过程记录施工过程中因混凝土浇筑对主缆预应力孔道造成破坏的成因及对策。通过结合实践数据的过程记录及分析来验证类似问题的解决策略,指导类似项目如何工前预防、工后补救,避免对工程造成不可逆的巨大损失。 相似文献
859.
860.
装船机是国内使用较多的港口散货装船设备,长江航运科学研究所研究设计的1500t/h环保型装船机的技术亮点是,采用了技术先进的除尘系统,确保有扬尘特性的物料在输送过程中整体收尘效果可以达到国家标准的要求。 相似文献