数值计算

In Chapter Ⅳ, the reliability of the scheme presented in this paper is proved by numerical experiments for solutions of shock tube flow problem and Laval nozzle flow problem. The treatment of boundary conditions is also described.

第四章通过对一维激波管、Laval管的数值计算验证了本文所采用的格式的可靠性，同时给出了边界条件的处理方法，并讨论了对应不同精度参数的TVD格式对计算结果的影响。

Without doubt, the pure numerical calculations are important and helpful to disclose the laser material interaction rule; however they are difficult to be used in practical application due to their lengthiness calculation time and high calculation cost.

然而，由于激光对材料表面改性处理问题非常复杂，原则上，一个能够真实反映热作用结果的较严格的温度场计算只能通过有限元、有限差分等纯数值计算方法来完成。

For the numerical integration in time, the fraction step method is used. This method is useful because one can use the same linear interpolation functions for both velocity and pressure.

在时间域上采用分步格式计算，这种方法与混合插值方法比较其优点是速度和压力可使用同阶线性插值，给数值计算带来很大方便。

Using about 3,120,000 grid cells and 512 CPUs, the parallel program has been successfully transplanted to the SZ MPP machine for massive parallel computation, giving for the first time the detailed flow properties of a model engine's combustor, offering a thorough performance analysis, and unprecedentedly obtaining some flowfield characteristics.

第三章介绍了数值计算方法及其验证。本文运用时间相关法，采用格心有限体积离散，—-—通鲤登经军巡型遇逊生匕一一一一一独立建立和发展了-谁球解混合与燃烧流场的基于PVM环境的并行计算程序。

Using about 3,120,000 grid cells and 512 CPUs, the parallel program has been successfully transplanted to the SZ MPP machine for massive parallel computation, giving for the first time the detailed flow properties of a model engines combustor, offering a thorough performance analysis, and unprecedentedly obtaining some flowfield characteristics.

第三章介绍了数值计算方法及其验证。本文运用时间相关法，采用格心有限体积离散，—-—通鲤登经军巡型遇逊生匕一一一一一独立建立和发展了-谁球解混合与燃烧流场的基于PVM环境的并行计算程序。

Directly from the theory of Kirchhoff diffraction, without any approximation about mathematical models, a series of improved digital calculation ways are used to ensure the high accuracy of OTF calculation.

直接从基尔霍夫衍射积分理论出发，在数学模型上考虑了瞳面振幅分布的不均匀性和倾斜因子，并采取一系列改进数值计算方法的措施，力求光学传递函数计算的高精度。

The pressure build-up curve has been analyzed using a multi-porosity medium model by...

本文还对这种多重介质的油井压力恢复曲线用有限元方法进行了数值计算，并分析了计算结果。

In this paper,the Newtonian fluid model was used to describe rheological property of the produced fluid,and motion equation of unsteady flow of Newtonian fluid in eccentric annulus with the inner cylinder reciprocating axially was transformed by means of the method of undetermined coefficients.

采用Newton流体模式描述油井产出液的流变性，利用待定系数法变换Newton流体在内管做轴向往复运动的偏心环空中非定常流的运动方程，建立给定流量下Newton流体在内管做轴向往复运动的偏心环空中非定常流的压力梯度计算公式，并利用有限体积法对压力梯度进行数值计算。

In order to calculate the wave making resistance of multi-hull ships,the Michell wave making method was modified.

为计算多体船兴波阻力，改进了Michell线性薄船兴波阻力数值计算方法。

The reason is many sided: 1 student and parent think " miscalculate " irrespective, as long as next time attentive dot went. The student allows to use a calculator in 2 education, the student had to the calculator depend on, often abandon when encountering seemingly complex calculation think, use a calculator directly, for instance 618, do not know to change brief into 13, achieve a result with the calculator directly however 0.33. Phase of 3 high school trains a student " put forward, analysis and the ability that solve a problem " the demand is higher and higher, of the train of thought that inscribes to solution in classroom education, thoughtway many somes more tuitional, and to operation ability, because the student has certain base, loosened with respect to some then. 4 emphasizes the training of all sorts of thinking ability overly, the training of operation ability has the suspicion that should try education it seems that, this also is one of reasons. The operation in 5 maths, no matter be numeric computation, return be algebraic type to be out of shape figure, photograph of the train of thought that inscribes with new knowledge, new solution, skill is compared and character, appear more as dry as a chip, the student does not have interest.

原因是多方面的：1学生和家长都认为"算错了"没关系，只要下次细心点就行了。2教学中答应学生使用计算器，学生对计算器有了依靠，在碰到貌似复杂的计算时往往舍弃思索，直接用计算器，比如618，不知化简成13，而是直接用计算器获得结果0.33.3高中阶段培养学生"提出、分析和解决新问题的能力"的要求越来越高，课堂教学中对解题的思路、思想方法的讲授多一些，而对于运算能力，因为学生都有一定的基础，于是就有些放松了。4过分强调各种思维能力的练习，运算能力的练习似乎有应试教育的嫌疑，这也是原因之一。5数学中的运算，不管是数值计算，还是代数式的变形演算，和新的知识、新的解题的思路、技巧相比较而言，显得比较枯燥，学生没有喜好。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新