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振動是大型液體火箭飛行過程中遇到的一個不容忽視的低頻振動問題,屬于流固耦合動力學研究范疇。
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.
分析結果表明,臨界阻尼比的增大會導致火箭結構系統(tǒng)失穩(wěn),而增大蓄壓器氣蝕柔度可降低臨界阻尼比,提高系統(tǒng)穩(wěn)定性;產生POGO振動時,結構振動的加速度響應最大,且推力脈動與加速度響應的相位差為-π/2;蓄壓器在推進系統(tǒng)上的安裝位置對POGO抑制有重要影響,給出了蓄壓器安裝的最佳位置。
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.
為了能夠快速有效地對各種構型的液體運載火箭可能出現的POGO振動問題進行初步分析,對液體運載火箭推進系統(tǒng)固有頻率的通用化計算問題進行了研究。
Through analyzing the theory of posture alignment,the cumulative properties of the posture and the stress state of 3-axis POGO sticks are revealed.
針對飛機數字化裝配中大部件調姿與對接問題,設計了一種精密三坐標POGO柱,在此基礎之上提出了一種基于三坐標POGO柱三點支撐的姿態(tài)調整方法。
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(醒腦開竅針刺加頭針法);
醒腦開竅針刺加頭針早期介入治療腦梗死的磁共振彌散加權成像對照研究
A Clinical Judgment of SCL-90 on Treating 50 cases of Depression with Scalp Acupuncture;
頭針治療抑郁發(fā)作SCL-90評定結果分析
Scalp Acupuncture for Treatment of Apoplexy and Effect on Plasma ET Content;
頭針治療中風及對血漿內皮素含量的影響
Significance of Nerve Stem Cells in the Research on Clinical Treatment of Ischemic Stroke with Scalp-acupuncture Therapy;
神經干細胞在頭針治療缺血性腦卒中研究中的意義
Scalp-acupuncture on Cell Apoptosis in Acute Cerebral Ischemia Reperfusion Injury Rats;
頭針對急性腦缺血再灌注大鼠細胞凋亡的影響
Effects of Scalp-acupuncture on Expression of Bcl-2/Bax in Acute Cerebral Ischemia/Reperfusion Injury Rats;
頭針對急性腦缺血再灌注大鼠Bcl-2/Bax表達的影響
Design and accuracy for POGO stick with three-axis
一種精密三坐標POGO柱設計與精度研究
Structure Design of POGO Stick with 3-DOF and Analysis of Its Mechanical & Dynamic Characteristics;
三坐標POGO柱的結構設計及其力學特性、動態(tài)特性分析
Posture Alignment for Large Aircraft Parts Based on Three POGO Sticks Distributed Support
基于POGO柱三點支撐的飛機大部件調姿方法
3-D Column Chart Button\\015\\015Creates a column chart with 3-D markers.
創(chuàng)建具有三維坐標刻度的柱形圖。
Discussion on the Calculation of Threefold Integral in a Cylindrical Coordinate System
在柱坐標系下三重積分計算法的探討
A practical algorthm of cylindricity evaluation on the three CMMs
三坐標測量機上圓柱度評定的一個實用算法
The Application of PML in Three Dimension Cylindrical Coordinates and the Conversion from Near Field to Far Field;
PML在三維柱坐標系下的應用及近場-遠場轉換
Numerical Simulation of Eletromagnetic Propagation Logging by FDTD in 3-D Cylindrical Coordinates
三維圓柱坐標系下FDTD法對電磁波傳播測井的數值模擬
Laplacian in the Columnar and Spherical Coordinates;
柱面坐標系和球面坐標系中的拉普拉斯算符
This coordinate system is called the triad at the point.
這個坐標系叫做該點的三面形坐標系。
Research on the Virtual Coordinate Measuring System of Coordinate Measuring Machines;
三坐標測量機虛擬坐標測量系統(tǒng)研究
Evaluation Algorithm of Cylindricity Error Based on Coordinate Transformation
基于坐標變換的圓柱度誤差評定算法
Traditional coordinate measuring machines (CMMs) with Cartesian coordinate system, columniation coordinate system and other coordinate systems are widely used.
傳統(tǒng)的坐標測量機大都基于一種幾何坐標系,如笛卡兒坐標系,柱坐標系等。
A 3-D perspective column chart compares data points along two axes, showing variation over a period of time or illustrates comparisons among items.
三維柱形圖沿兩個坐標軸比較數據點，顯示一段時間內的變化或圖示項目之間的比較情況。
three-dimensional search and height finding radar
三坐標搜索與測高雷達
The third coordinate is elevation.
第三項坐標是高程。
Method of 2D and 3D Radar Registration and Its Application
兩坐標與三坐標雷達配準方法及其應用分析
Transformation Between Three-Dimension Geocentric Coordinate System and Independent Coordinate System
區(qū)域性獨立坐標系與三維地心坐標系的轉換