数值技术

However, a numerical value is necessary so various techniques are used to obtain a quantitative value.

然而这个特性的数值是必要性的，因此要用多种技术及方法来获取这一项数值。

Based on this, a new WENO difference scheme which based on Dispersion-Relation-Preserving relation is developed, and representative test cases with this scheme for computational aeroacoustics problems has been implemented and compared in order to test capability of wave capturing; In addition, WENO schemes generally do not converge at high order in the presence of contact discontinuity of Euler equations, so a conservative front tracking technique coupling WENO schemes and Level Set method to simulate the translating density profile is presented here, and numerical simulation with this technique for representative test case has been implemented and results show the desired accuracy.

本文研究了高阶精度加权基本无振荡格式及其在双曲守恒律方程中的应用，在此基础上作了两个方面的工作：一是针对高频声波问题构造出一种基于保色散关系的WENO有限差分格式，并对计算气动声学问题的代表性算例进行了大量数值实验，比较了该格式捕捉波数的能力；另外，针对高阶WENO格式在处理Euler方程的接触间断时精度有所降低的问题，研究了利用界面追踪技术Level Set方法和高阶激波捕捉WENO格式相结合的一种守恒追踪方法，并且给出有代表性的密度滑移面问题的算例，得到一致高阶精度的数值模拟结果。

As a fast TDIE solver with high accuracy and efficiency, plane wave time domain algorithm is studied deeply in this thesis. The implementations of two-level and multilevel PWTD-enhanced MOT schemes are described and the numerical efficiency is presented.

论文还深入研究了一种高精度、高效率的TDIE加速算法——时域平面波算法的理论基础、数值实现的关键技术，以及两层、多层PWTD加速MOT的实现方案、程序流程以及数值性能。

The ideal program for developing penetration technique is approached from the aspects of reservoir heterogeneity, initial proration velocity and optimal perforation plan (the extent of perforation and height of water avoidance ).

运用数值模拟的方法，结合油田的实际资料，建立了数值模拟模型，从油藏非均质性、初配产速度及最佳射孔方案等方面，探讨了水力深穿透射孔技术开发底水油藏的理想方案。

In order to resolve this problem,an effective conversion of fitted-body coordinate has been used in numerical simulations of flow field within a facture of layered medium ,resulting in a successful transformation of 2D flow-field calculation within a fracture from a complex physics domain to a regular calculation domain.

为了有效地攻克这一技术难关，在层状介质缝内流场数值模拟中，采用了有效的贴体坐标变换，成功地将二维缝内流场计算从复杂的物理域转换到规则的计算域，从而为我国全三维水力压裂数值模拟软件的开发和应用提供了良好的理论基础和新的思路。

By means of different subjects and te chniques,the paper makes an overall study on the crustal stability of Beihuaiyang region and its adjace nt areas from the aspects of current t ectonic stress fields,principal fa ult structures,analysis of regional fa ults and neotectonic activity,seis mic activity and numerical modeling,etc.

运用多学科、多技术相结合的研究方法，从现今构造应力场特征、现代地壳形变特征、主干断裂构造以及区域断裂活动性分析、新构造运动、地震活动、数值模拟等方面入手，对北淮阳及其邻接区地壳稳定性进行了全面而系统的研究，指出本区地震活动受走滑活动断裂控制，中、强地震集中于区内东南部和西北部NW向与NE向断裂交汇处；第四纪无大规模差异升降运动；数值模拟等综合分析表明，信阳地区的区域构造稳定性高，现代地壳形变量小，应力平缓，地震活动少且弱。

Furthermore, the statistical characteristics of the flow fields at the stator passage are obtained from the data of SPIV measurement, and the turbulence kinematic energy fields and Renold Stress fields are analyzed in primary at both design and near stall conditions.

从SPIV测量结果及CFD数值模拟结果来看，当前的CFD数值模拟技术在模拟真实压气机时，模拟结果总体趋势是正确的，但在具体流动细节上，其计算精度和可靠性还有待于进一步提高。

Detailed work have done at four aspects as follows: the usage of SPIV in multistage turbomachinery; the study of compressor rotor tip complex flow with SPIV; the study of compressor stator tip complex flow with Rotor/Stator interaction and the detailed analysis and comparison of the unsteady flow field respectively obtained by CFD and experiment investigation.

详细本文主要以SPIV非定常实验测量和CFD非定常数值模拟为工具，研究叶轮机端壁复杂流动的一些机理性问题，围绕四个方面开展了叶轮机端壁非定常流动方面的研究工作：适用于多级叶轮机械使用的SPIV技术；压气机转子尖区复杂流动；动静叶干扰条件下压气机静子内尖区非定常流动；以及非定常数值模拟结果与非定常实验测量结果的对比。

As the beginning of this thesis, the important meanings of sea ice to global climate change and ocean engineering in polar and subpolar sea regions are explained firstly. Then, it is pointed out that sea ice numerical modelling, as a powerful tool of sea ice research, is limited by the precision of parameters within models instead of itself so far. It is meaningful to study the important parameters of sea ice dynamics by means of the rapidly developing digital imaging techniques so as to provide better input parameters needed in numerical models.

文中首先阐述了海冰对全球气候变化和极区、亚极区海域海洋工程问题的重要性，并指出作为海冰研究重要手段之一的海冰数值模拟发展到目前，其准确性更加受到海冰参数而非模式本身的限制，因此以目前快速发展的数字图像技术为工具对海冰动力学过程中的重要参数进行研究，以提供数值模式所需要的高精度和准确性的数据，是非常有必要的。

The main research areas of this paper include:For simulation model of cyclist dummy, it is proposed that a combined custom modeling technique set up new cyclist dummy that adapts for two-wheeler collision accidents. The technique is achieved based on the analysis of modeling features of existing numerical dummy and the problems that occur when it is used to simulate the two-wheeler cyclists.

研究的主要方面包括：在两轮车骑车人仿真假人模型的研究方面，通过分析现有数值假人的建模特点和其用于对骑车人进行仿真模拟上存在的问题，根据本文研究的需要，提出组合式定制假人建模技术建立适合于两轮车碰撞事故研究的骑车人数值仿真假人。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。