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91.
使用1 053 nm脉冲激光分别辐照铝合金单板和铝合金/水结构,通过表面形貌观察、温度场分析、熔穿时间测量等手段,分析了水的存在对铝合金壳体烧蚀的影响。运用有限元软件ANSYS,建立了脉冲激光辐照下单板及结构温度变化的数值模型,计算了铝合金表面熔凝区域的尺寸,并与实验结果进行了对比。结果表明:在相同的实验条件下,辐照8个激光脉冲时,铝合金单板即被熔穿,而辐照10个脉冲后铝合金/水结构仍未发生熔穿,且结构中铝合金表面的熔凝区域要小于单板情形中的熔凝区域,这表明水的存在对延缓铝合金板的烧蚀有较大的作用。对于单板情形,计算结果与实验结果符合较好,而对于铝合金/水结构情形,数值模拟放大了铝合金壳体的温升,这主要是因为数值模拟程序未考虑水的对流及沸腾换热对计算结果的影响。 相似文献
92.
储油罐的变位识别与罐容表标定 总被引:1,自引:0,他引:1
研究了储油罐的变位识别与罐容表重新标定的问题,利用三重积分的方法和Maple软件对平底椭圆柱储油罐油量的表达式进行了精确求解,并利用实验数据对求解结果进行了误差补偿;利用近似积分算法对主体为圆柱,两端为球冠的储油罐的油量表达式进行了近似求解,通过建立优化模型,搜索算法和Matlab软件求解出了问题二中的变位角度,并利用实验数据对求解结果进行了检验;最后利用得到的油量表达式给出了两个储油罐的罐容表. 相似文献
93.
Tuned liquid dampers (TLDs) utilize sloshing fluid to absorb and dissipate structural vibrational energy. Simple TLD tank geometries may not always be feasible due to space limitations. While the non-linear modelling of sloshing fluid is currently limited to tanks of simple geometries, this paper develops a non-linear multimodal model which describes the sloshing behaviour of a fluid in a flat-bottom tank of arbitrary geometry. The mode shapes of the sloshing fluid are found by solving the Helmholtz equation over the tank domain using the finite element method. The Bateman-Luke variational principle is used to develop a system of ordinary differential equations which account for the coupling of the sloshing modes through the non-linear free surface boundary conditions. Damping is incorporated into the model by considering the drag produced on a set of damping screens inserted in the fluid. The system of ordinary differential equations is solved using the Runge-Kutta-Gill Method to predict the wave heights and sloshing forces. In general, the mode shapes in an arbitrary tank will have components in two orthogonal (x- and y-) directions. This out-of-plane behaviour is an important consideration for TLD design. The model is validated with existing models for the special cases of rectangular and circular tanks. Lastly, new shake table tests are conducted on a tank of complex geometry. 相似文献
94.
近年来随着海水养殖业的发展,因海水养殖而对环境造成的污染得到人们的重视,联合养殖系统作为一种环境友好的养殖方法,成为目前海水养殖的研究热点.本文综述了联合养殖系统中"藻塘"和"食藻动物塘"的研究进展,并对其未来发展方向进行了预测. 相似文献
95.
In the present paper, in order to investigate the effect of free surface on drag and lift coefficients of an Autonomous Underwater vehicle,1 two phase flow Reynolds Averaged Navier–Stokes (RANS) equations were solved using computational fluid dynamics. The numerical results were compared with those obtained from both numerical single phase flow simulations and the experiments conducted in the towing tank of the Subsea R&D Center at Isfahan University of Technology, using a 1:1 scale model of AUV developed in this center. The study was conducted at various submergence depths ranging from 0.87 to 5.22 of the AUV diameter and at the speeds of 1.5 and 2.5 m/s (corresponding to Reynolds numbers of 1.9 and 3.17 million, respectively). The variation of drag and lift coefficients of the AUV with the submergence depth were shown to be very sensitive to the AUV speed. 相似文献
96.
首先,从战场信息感知的功能入手,提出了信息条件下坦克智能体的感知行为模型框架;然后,分析了感知行为产生的要素,建立了坦克智能体观察模型;最后,通过战场态势进一步说明建立模型的必要性。 相似文献
97.
98.
Computational fluid dynamics (CFD) is used extensively by engineers to model and analyze complex issues related to hydraulic design, planning studies for future generating stations, civil maintenance and supply efficiency. In order to find the optimal position of a baffle in a rectangular primary sedimentation tank, computational investigations are performed. Also laboratory experiments are conducted to verify the numerical results and the measured velocity fields which were by Acoustic Doppler Velocimeter (ADV) are used. The GMRES algorithm as a pressure solver was used in the computational modeling. The results of computational investigations performed in the present study indicate that the favorable flow field (uniform in the settling zone) would be enhanced for the case that the baffle position provide small circulation regions volume and dissipate the kinetic energy in the tank. Also results show that the GMRES algorithm can obtain the good agreement between the results of numerical models and experimental tests. 相似文献
99.
100.