非绝热壁叶栅的粘性流动

非绝热壁叶栅的粘性流动王正明（中国科学院工程热物理研究所北京１０００８０）关键词非绝热壁；叶栅；粘性流动１引言近年来，随着计算机运算速度的提高，叶轮机械内部粘性流动的数值解法发展很快，对于动量方程，已广泛采用亘接求解不作简化的完全的Ｎ－Ｓ方程，以便更...     

误差性质的一种判据

一、判据我们在医用物理实验过程中,在实验设计、误差分析、数据处理以及实验结果的表述上都需要明确判断所观测的量是以偶然误差为主,还是以系统误差为主,还是两者共存。我们在教学过程中,曾提出过几种不同的判据,但最后倾向一致的判据可表述如下。     

ITER第一壁、偏滤器靶板和壁的热负荷计算

由于日本和欧共体对固体氚增殖包层已进行了很多实验研究，并且提出了他们的1TER固体氚增殖包层模块(TBM)方案。为了设计具有中国研究基础的氚增殖包层模块方案，我们选定液态锂和锂-铅作为氚增殖材料的ITER包层模块方案。但是包层第一壁的厚度一般只有2～3cm，因为它必须小于14．1MeV聚变中子的平均自程，从结构力学的角度它是非常单薄的。     

一种适用于对称截面的主动式热斗篷的研究

直接求解导热方程对具有自适应热源的可控式热隐身技术进行数值研究,探索热流控制方法及隐身效果,推导出均匀背景下二维对称截面热斗篷热隐身区域自适应热源分布的通解.仿真结果表明:对于任意对称截面斗篷,自适应热源都能使得扰动后的温度场很好地恢复到背景温度场,达到热隐身的目的.     

ITER第一壁铍铜连接部件在高热负荷作用下的热性能分析

对ITER屏蔽包层第一壁板铍铜连接件在高热负荷作用下的传热性能进行了分析,模拟了第一壁铍铜连接手指部件的热应力和热应变,得到其对应的热疲劳寿命.计算结果表明,在局部4.7MW?m-2高热负荷作用和ITER水冷条件下,现有设计方案中的铍铜连接件的热性能和热疲劳性能均满足设计要求.     

管道连接装配型ITER增强热负荷第一壁的热工水力分析

对管道连接装配型ITER增强热负荷第一壁(EHF FW)的标准手指对、边缘手指对及中心梁(CB)开展了热工水力分析.分析结果显示流速分布合理,低于1m·s-1或高于10m·s-1的区域非常小;手指对间的流量分配较合理;整个第一壁的压降为0.351MPa,小于0.4MPa的限定值;在8个循环周期内CB最高温度为409.2...     

自由流区近壁蒸发及未蒸发颗粒的热泳分析

本文给出了自由分子流区作用在壁面附近蒸发及未蒸发颗粒上的热泳力的分析结果.分析中气体分子在壁面和颗粒表面处均假定为部分镜反射和部分漫反射.分析表明,作用在近壁颗粒上的热泳力不仅依赖于气体中的温度梯度,还和气体的压力以及壁面与气体温度比有关.颗粒表面的温度和镜反射分数对作用于未蒸发颗粒的热泳力没有影响,但明显影响作用于蒸发颗粒的热泳力.研究表明,近壁效应及蒸发对颗粒热泳的附加影响是不容忽视的.     

Z箍缩驱动混合堆第一壁热-力学瞬态响应分析

利用ANSYS程序对Z箍缩驱动聚变-裂变混合堆(Z-FFR)第一壁在瞬态热流加载下的热-力学响应进行了模拟计算,分析了第一壁温度、应力随时间和深度的分布。结果表明,周期性脉冲加载不会导致第一壁产生温度累积效应,第一壁温度峰值409 ℃,出现在钨层表面,钨层最大应力140 MPa,锆合金基底最大应力33 MPa。     

二维非结构网格有限体积格式的壁热现象和人工热流方法

基于Noh人工热流方法的思想,推导出任意多边形网格人工热流的格式,将Noh的结构网格人工热流方法推广到任意多边形非结构网格的拉氏有限体积方法中,抑制或消除了壁热现象.几个数值实验,包括Noh激波反射问题和两块钢金属碰撞问题,验证了方法的可行性.     

一维理想弹塑性流体的数值模拟及壁热现象的抑制

针对一维理想弹塑性流体的Wilkins模型,提出HLLC型的近似黎曼解法器.该解法器引入塑性波并保证波的个数和真实的物理情况一致,其中波速选取由波系的特征分析来确定.整个算法实施简单,无需迭代,为减少强冲击（稀疏）模拟时的壁热误差,设计相应的壁热粘性,有效地抑制了非物理的壁热现象.     

Relation Between Dimension and Angular Momentum for Radially Symmetric Potential in N-Dimensional Space

It is proved that when solving SchrSdinger equations for radially symmetric potentials the effect of higher dimensions on the radial wave function is equivalent to the effect of higher angular momenta in lower-dimensional cases. This result is applied to giving solutions for several radially symmetric potentials in N dimensions.     

Towards a Physical Interpretation for the Stephani Universes

A physically reasonable interpretation is provided for the perfect fluid, spherically symmetric, conformally flat "Stephani Universes". The free parameters of this class of exact solutions are determined so that the ideal gas relation p = nk _B T is identically fulfilled, while the full equation of state of a classical monatomic ideal gas and a matter-radiation mixture holds up to a good approximation in a near dust, matter dominated regime. Only the models having spacelike slices with positive curvature admit a regular evolution domain that avoids an unphysical singularity. In the matter dominated regime these models are dynamically and observationally indistinguishable from "standard" FLRW cosmology with a dust source.     

Relation Between Dimension and Angular Momentum for Radially Symmetric Potential in N-Dimensional Space

It is proved that when solving Schr(o)dinger equations for radially symmetric potentials the effect of higher dimensions on the radial wave function is equivalent to the effect of higher angular momenta in lower-dimensional cases.This result is applied to giving solutions for several radially symmetric potentials in N dimensions.     

On the HLLC Riemann solver for interface interaction in compressible multi-fluid flow

In this work, the HLLC Riemann solver, which is much more robust, simpler and faster than iterative Riemann solvers, is extended to obtain interface conditions in sharp-interface methods for compressible multi-fluid flows. For interactions with general equations of state and material interfaces, a new generalized Roe average is proposed. For single-phase interactions, this new Roe average does not introduce artificial states and satisfies the U-property exactly. For interactions at material interfaces, the U-property is satisfied by introducing ghost states for the internal energy. A number of numerical tests suggest that the proposed Riemann solver is suitable for general equations of state and has an accuracy comparable to iterative Riemann solvers, while being significantly more robust and efficient.     

Quasi-Periodic Solutions and Asymptotic Properties for the Isospectral BKP Equation

In this paper, based on a Riemann theta function and Hirota's bilinear form, a straightforward way is presented to explicitly construct Riemann theta functions periodic waves solutions of the isospectral BKP equation.Once the bilinear form of an equation obtained, its periodic wave solutions can be directly obtained by means of an unified theta function formula and the way of obtaining the bilinear form is given in this paper. Based on this, the Riemann theta function periodic wave solutions and soliton solutions are presented. The relations between the periodic wave solutions and soliton solutions are strictly established and asymptotic behaviors of the Riemann theta function periodic waves are analyzed by a limiting procedure. The N-soliton solutions of isospectral BKP equation are presented with its detailed proof.     

基于黎曼解的粒子间接触算法在SPH中的应用

采用光滑粒子流体动力学（SPH）方法模拟大变形问题具有明显的优点,但传统的SPH方法在模拟冲击波与接触界面的作用时,往往会出现压力的反常跳动。采用黎曼解描述粒子间相互作用的接触算法对传统SPH方法进行修正,计算了激波管和飞片碰撞（包含接触界面）问题中波的传播,并将计算结果与解析解作比较。结果表明,与传统的光滑粒子法相比,该改进的光滑粒子法无需引入人工粘性项和人工热流项,程序结构简洁,且能较好地处理接触界面问题,从而能有效提高计算精度。     

Quasi-Periodic Solutions and Asymptotic Properties for the Isospectral BKP Equation

In this paper, based on a Riemann theta function and Hirota's bilinear form, a straightforward way is presented to explicitly construct Riemann theta functions periodic waves solutions of the isospectral BKP equation. Once the bilinear form of an equation obtained, its periodic wave solutions can be directly obtained by means of an unified theta function formula and the way of obtaining the bilinear form is given in this paper. Based on this, the Riemann theta function periodic wave solutions and soliton solutions are presented. The relations between the periodic wave solutions and soliton solutions are strictly established and asymptotic behaviors of the Riemann theta function periodic waves are analyzed by a limiting procedure. The N-soliton solutions of isospectral BKP equation are presented with its detailed proof.