POGO vibration is a low-frequency vibration problem which can not be ignored in the course of liquid rocket flight, it belongs to fluid-solid coupling dynamics.
POGO振动是大型液体火箭飞行过程中遇到的一个不容忽视的低频振动问题,属于流固耦合动力学研究范畴。
The acceleration response of the vibration reaches maximum when the POGO vibration happens,and the phase difference between the pulsatory thrust force and the acceleration response is equal to-π/2.
分析结果表明,临界阻尼比的增大会导致火箭结构系统失稳,而增大蓄压器气蚀柔度可降低临界阻尼比,提高系统稳定性;产生POGO振动时,结构振动的加速度响应最大,且推力脉动与加速度响应的相位差为-π/2;蓄压器在推进系统上的安装位置对POGO抑制有重要影响,给出了蓄压器安装的最佳位置。
For the purpose of fast and effective elementary analysis of POGO vibration problem which possibly appear in the liquid launch vehicle engine,the study on calculation of natural frequency for engine flow system, with general applicability to any liquid launch vehicle engine, is proposed.
为了能够快速有效地对各种构型的液体运载火箭可能出现的POGO振动问题进行初步分析,对液体运载火箭推进系统固有频率的通用化计算问题进行了研究。
Through analyzing the theory of posture alignment,the cumulative properties of the posture and the stress state of 3-axis POGO sticks are revealed.
针对飞机数字化装配中大部件调姿与对接问题,设计了一种精密三坐标POGO柱,在此基础之上提出了一种基于三坐标POGO柱三点支撑的姿态调整方法。
A control study of magnetic resonance diffusion weighted imaging of patients with acute cerebral infarction and early(<48 hours) intervention with resuscitating and scalp acupuncture therapies(醒脑开窍针刺加头针法);
醒脑开窍针刺加头针早期介入治疗脑梗死的磁共振弥散加权成像对照研究
A Clinical Judgment of SCL-90 on Treating 50 cases of Depression with Scalp Acupuncture;
头针治疗抑郁发作SCL-90评定结果分析
Scalp Acupuncture for Treatment of Apoplexy and Effect on Plasma ET Content;
头针治疗中风及对血浆内皮素含量的影响
Significance of Nerve Stem Cells in the Research on Clinical Treatment of Ischemic Stroke with Scalp-acupuncture Therapy;
神经干细胞在头针治疗缺血性脑卒中研究中的意义
Scalp-acupuncture on Cell Apoptosis in Acute Cerebral Ischemia Reperfusion Injury Rats;
头针对急性脑缺血再灌注大鼠细胞凋亡的影响
Effects of Scalp-acupuncture on Expression of Bcl-2/Bax in Acute Cerebral Ischemia/Reperfusion Injury Rats;
头针对急性脑缺血再灌注大鼠Bcl-2/Bax表达的影响
Design and accuracy for POGO stick with three-axis
一种精密三坐标POGO柱设计与精度研究
Structure Design of POGO Stick with 3-DOF and Analysis of Its Mechanical & Dynamic Characteristics;
三坐标POGO柱的结构设计及其力学特性、动态特性分析
Posture Alignment for Large Aircraft Parts Based on Three POGO Sticks Distributed Support
基于POGO柱三点支撑的飞机大部件调姿方法
3-D Column Chart Button\\015\\015Creates a column chart with 3-D markers.
创建具有三维坐标刻度的柱形图。
Discussion on the Calculation of Threefold Integral in a Cylindrical Coordinate System
在柱坐标系下三重积分计算法的探讨
A practical algorthm of cylindricity evaluation on the three CMMs
三坐标测量机上圆柱度评定的一个实用算法
The Application of PML in Three Dimension Cylindrical Coordinates and the Conversion from Near Field to Far Field;
PML在三维柱坐标系下的应用及近场-远场转换
Numerical Simulation of Eletromagnetic Propagation Logging by FDTD in 3-D Cylindrical Coordinates
三维圆柱坐标系下FDTD法对电磁波传播测井的数值模拟
Laplacian in the Columnar and Spherical Coordinates;
柱面坐标系和球面坐标系中的拉普拉斯算符
This coordinate system is called the triad at the point.
这个坐标系叫做该点的三面形坐标系。
Research on the Virtual Coordinate Measuring System of Coordinate Measuring Machines;
三坐标测量机虚拟坐标测量系统研究
Evaluation Algorithm of Cylindricity Error Based on Coordinate Transformation
基于坐标变换的圆柱度误差评定算法
Traditional coordinate measuring machines (CMMs) with Cartesian coordinate system, columniation coordinate system and other coordinate systems are widely used.
传统的坐标测量机大都基于一种几何坐标系,如笛卡儿坐标系,柱坐标系等。
A 3-D perspective column chart compares data points along two axes, showing variation over a period of time or illustrates comparisons among items.
三维柱形图沿两个坐标轴比较数据点，显示一段时间内的变化或图示项目之间的比较情况。
three-dimensional search and height finding radar
三坐标搜索与测高雷达
The third coordinate is elevation.
第三项坐标是高程。
Method of 2D and 3D Radar Registration and Its Application
两坐标与三坐标雷达配准方法及其应用分析
Transformation Between Three-Dimension Geocentric Coordinate System and Independent Coordinate System
区域性独立坐标系与三维地心坐标系的转换