| 1. | Lattice boltzmann method ; boundary treatment ; flow around cylinder ; parallel computation
玻尔兹曼方法边界处理圆柱绕流并行计算 |
| 2. | Lbm is a recent developed method with advantage of high parallel performance and easy boundary treatment . for curvilinear boundary , a new method has been adopted for simulation of flow around cylinder with
Lattice boltzmann method lbm是一种近年来发展的一种数值方法。它具有并行效率高，边界处理简单的特点。本文采用一种能对曲线边界进行较好处理的方法，用lbm对 |
| 3. | Aiming at the limitation of classical boundary extension methods , interpolating subdivision method is brought forward to resolve boundary treatment problem by taking different subdivision depending on the position of image data ( three conditions )
还针对传统延拓边界处理方法缺陷，采用插值细分算法对图像信息数据所在位置不同(分三种情况) ，用不同插值方式处理数据来解决边界问题。 |
| 4. | Results indicate that although established program uses traditional vibration solution , from the point of view of dams " dynamic stability analysis during earthquakes , its solution and boundaries treatment are feasible and can meet needs of practical projects
计算结果表明，原有程序虽然采用的是结构分析中的振动解法，但从土坝地震稳定性分析角度而言，原来程序的算法及边界处理是可行的，可以满足实际工程的需要。 |
| 5. | A patch antenna with air holes in the substrate has been designed . the finite - difference time - domain ( fdtd ) method together with the perfectly matched layer ( pml ) boundary treatment has been used to study the performance of the antenna . it is shown that the surface waves are significiently suppressed , the frequency bandwidth is improved , the sidelobe levels are reduced and consequently the gain in the forward direction is improved by 14 db ( about 4 db higher than the value reported previously )
设计了一种基底钻周期圆孔结构的电磁(光子)晶体贴片天线，用fdtd方法并结合pml吸收边界条件对该天线进行了研究，结果表明本文所设计的基底钻孔型电磁晶体贴片天线取得了多方面的性能改善，与普通天线相比，基底中的表面波受到很大抑制，天线的带宽增加，远场方向图上天线的旁瓣和背瓣被明显削弱，向前辐射的增益由原来的12db增加到26db ，增加了14db ，比文献上报道的gonzalo等人的研究结果提高了4db 。 |
| 6. | Based on the simulation method of finite difference time domain ( fdtd ) ( together with the boundary treatment of an anisotropic perfect matched layer of absorbing media for the truncation of fdtd lattices ) and the theory of ordinary antennas , antennas based on photonic bandgap ( pbg ) materials and meta - materials are studied in the present dissertation
在开展有限时域差分法(结合各向异性完全匹配层边界)算法研究和普通天线模拟设计研究的工作基础上，本论文主要进行了基于光子晶体( pbg )与异向介质的新型天线的研究。 |
| 7. | Based on the analysis of the monitoring data during construction and the settlement of stacking yard surveyed after 2 years ' operation , this paper introduces the design and construction of sct2 ground treatment engineering , and main technical problems such as drilling holes and boundary treatment , together with relevant solutions
摘要结合施工过程中的各项监测数据及堆场使用2年后的沉降情况，介绍sct2地基处理工程的设计、施工情况，以及施工中存在的引孔、边界处理等主要技术问题及其解决办法。 |
| 8. | The numerical algorithm of solving the adjoint equations for different design cases have been developed by using finite volume methodology which is usually used to solve the flow governed equation . it includes the some important aspects , such as flux formulation , wall and far - field boundary treatment methodology , dissipative term formulation , etc . after the solution of the adjoint equations is obtained , the derivatives of the cost function with respect to all the design variables can be evaluated with the same operation . this can yields a significant saving over the other gradient - based techniques when there are many design variables
( 3 )进行了应用控制理论和三维欧拉方程的机翼气动反设计研究，以及有升力约束情形下机翼跨音速减阻问题研究，分别推导了相应的共轭方程及边界条件数学表达形式，研究与发展了三维共轭方程的有限体积数值求解方法，及相应梯度公式的数值求解方法，通过对计算网格生成、流场计算、共轭方程数值求解、梯度求解和优化算法等多方面的有效结合，成功发展了三维机翼的气动反设计和跨音速减阻优化设计程序，成功地进行了多个设计算例研究。 |
| 9. | The performance of the pbg antenna using the new pbg cover together with a pbg substrate is studied by the fdtd method together with the pml boundary treatment . the numerical results show that a more focused beam radiated in the broadside direction is achieved . the gain of the pbg patch antenna in the forward direction is improved by about 6 db . the radiation directivity is improved significantly and reaches 11 . 5 db , which is 0 . 4 db less than the maximum value that is allowed physically for this size of the antenna ( this difference is about 4 . 1 db less than the difference achieved by thevenot et al . ,
用fdtd方法并结合pml吸收边界条件，我们对加了这种新的覆层结构并且基底钻孔的复合结构电磁(光子)晶体贴片天线的性能进行了研究，结果证明加了这种新的电磁晶体覆层结构以后，天线的波束收拢很多，并且向前辐射的增益大大提高，与普通天线相比，天线的e面和h面方向图上向前辐射的增益均提高了约6db ，另外，该复合结构天线的方向性系数达到了11 . 5浙江大学博士学位论文db ，与该物理尺寸天线的方向性系数的理论极限值( 11 . 9db )相差0 . 4db ，该差值比thevenot等人设计的电磁晶体覆层天线的相应差值减少了约4 . 1db ，比qiu等人设计的电磁晶体天线的相应差值减少了约1 |
