计算流体力学的时空观:模型的时空关联性及算法的时空耦合性

流体力学中波的有限传播、粒子的碰撞、各种力之间相互作用,无不体现时空关联效应.本文从计算方法的视角探讨计算流体力学的时空观,即流体力学模型的时空关联性和计算方法的时空耦合性.从流体力学微团法建模出发,明确模型时空关联性的涵义,建立有限体积格式的基本原理,阐述算法时空耦合的必要性,实现流体力学基本控制方程物理建模与有限体...     

An inverse design method for supercritical airfoil based on conditional generative models

Inverse design has long been an efficient and powerful design tool in the aircraft industry.In this paper, a novel inverse design method for supercritical airfoils is proposed based on generative models in deep learning. A Conditional Variational Auto Encoder(CVAE) and an integrated generative network CVAE-GAN that combines the CVAE with the Wasserstein Generative Adversarial Networks(WGAN), are conducted as generative models. They are used to generate target wall Mach distributions for the inve...     

暗条模型中暗条电流纵向分量的考虑

用暗条电流模型中矩形电流回路来研究NOAA131活动区暗条,结果得到暗条上升时弯曲成"U"形态,跟观测结果不符.因此本文推知:考虑暗条电流的纵向分量时一种椭圆形回路似乎比矩形回路更接近于暗条实际.      

基于对象的P&ID设计软件无向图模型

在开发P&ID辅助设计系统的过程中,需要表示实体间的逻辑拓扑信息.为避免引入附加抽象实体来表示逻辑拓扑信息带来的复杂性,提出以面向对象为基础将逻辑拓扑信息统一在实体本身数据结构中的方法,并介绍了从P&ID管网图抽象建立P&ID无向图模型的过程.此方法和模型在实践中取得了很好的效果.对P&ID无向图结构的特点做了深入分析,指出运用此模型建立P&ID系统的要点及运用中应注意的问题,并讨论了P&ID无向图模型的扩展.      

旋转平板型叶端气膜冷却实验研究

在相似理论指导下, 对旋转系流动与换热方程以及边界条件进行无量纲化, 得出了描述旋转气膜冷却效率与换热系数的一系列准则, 设计并建立了实验台, 解决了从高速旋转部件上引出测试信号而不失真及对旋转试件进行强电加热等问题, 并在旋转情况下, 对常用的平板型叶端气膜冷却效率及其换热系数进行了实验研究, 并总结出可供工程参考的准则公式.      

飞航导弹分层变结构控制

飞航导弹模型可以处理成一种四层非线性、时变块对角结构，但其中一、二层模型不是仿射型模型，这在控制理论的应用上受到限制。本文应用优化线性理论，对这两层模型进行了仿射型处理，这样就得到了飞航导弹的四层非线性信射型模型。接着，本文提出了玫类非线性系统的变结构控制方法，从而对导弹进行了分层变结构控制器设计。仿真结果表明，所设计的系统具有很强的鲁棒性。     

Observations and theory of cataclysmic variables: On progress and problems in understanding dwarf novae and nova-like stars

After brief historical and theoretical introductions to the field, observed properties of dwarf novae and non-magnetic nova-like stars are reviewed. Photometric observations splitted into events on time-scales of months to years (outburst light curves), hours (orbital light curves) and minutes and below (flickering and oscillations), respectively, and spectroscopic observations are presented. The emphasis is on one hand on the features common to many objects in an attempt to gain some impression on what could be considered typical features. On the other hand observations are highlighted that spectacularly deviate from these common trends as they may give some hint as to what the possible range of variability is. Whenever possible, the implications for the physical properties and possible models of the systems are pointed out. Furthermore, for each section the current status of the conceptual understanding and attempts to model this are briefly reviewed and, finally, confronted with the observations.     

A NEW FATIGUE CUMULATIVE DAMAGE DYNAMIC INTERFERENCE MODEL

ＡＮＥＷＦＡＴＩＧＵＥＣＵＭＵＬＡＴＩＶＥＤＡＭＡＧＥＤＹＮＡＭＩＣＩＮＴＥＲＦＥＲＥＮＣＥＭＯＤＥＬＬｉａｏＭｉｎ；ＹａｎｇＱｉｎｇｘｉｏｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＡｉｒｃｒａｆｔＥｎｇｉｎｅｅｒｉｎｇ，ＮｏｒｔｈｗｅｓｔｅｒｎＰｏｌｙｔｅｃｈ...     

STUDY ON ROTOR HEAD VIBRATION ABSORBER OF HELICOPTER

ＳＴＵＤＹＯＮＲＯＴＯＲＨＥＡＤＶＩＢＲＡＴＩＯＮＡＢＳＯＲＢＥＲＯＦＨＥＬＩＣＯＰＴＥＲＧｕＺｈｏｎｇｑｕａｎ；ＰｅｎｇＦｕｊｕｎ；ＭａＫｏｕｇｅｎ（ＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｉｅｏｆＶｉｂｒａｔｉｏｎＥｎｇ，ＮａｎｊｉｎｇＵｎｉｖｅｒｓｉｔｙ...     

A DYNAMIC MODEL OF THE SOLAR-POWERED SOLID ABSORPTION REFRIGERATION SYSTEM

ＡＤＹＮＡＭＩＣＭＯＤＥＬＯＦＴＨＥＳＯＬＡＲ－ＰＯＷＥＲＥＤＳＯＬＩＤＡＢＳＯＲＰＴＩＯＮＲＥＦＲＩＧＥＲＡＴＩＯＮＳＹＳＴＥＭＬｉｎＧｕｉｐｉｎｇ；ＭｅｉＺｈｉｇｕａｎｇ（Ｆａｃｕｌｔｙ５０５，ＢｅｉｊｉｎｇＵｎｉｖｅｒｓｉｔｙｏｆＡｅｒｏｎａｕ...