【摘 要】
:
Data extracted from time-of-flight (TOF) measurements with more than two peaks made for steady-state He free jets at G¨ottingen already in 1986 [1],for steady-state CO2 free jets [2] and for pulsed Ne
【机 构】
:
Chemical and Biomolecular Engineering Dept.,University of California at Los Angeles,Los Angeles,CA 9
【出 处】
:
29th International Symposium on Rarefied Gas Dynamics(第29届国际
论文部分内容阅读
Data extracted from time-of-flight (TOF) measurements with more than two peaks made for steady-state He free jets at G¨ottingen already in 1986 [1],for steady-state CO2 free jets [2] and for pulsed Ne free jets investigated recently at Tel Aviv have been added to Fig.1 of Ref.[3],where the terminal condensed-phase mass fraction x21 is plotted as a function of the dimensionless scaling parameter Γ.Γcharacterizes the source (fluid species,temperature,pressure and throat diameter); values of x21 are extracted from TOF measurements using conservation of energy in the free-jet expansion [3].
其他文献
机械设备在运行过程中,因工况复杂、过载等原因引起的性能退化及失效时有发生.滚动轴承作为机械结构的薄弱环节之一,除了要承受能量转换零部件传递给基础的交变载荷,还要承受工况波动引起的随机载荷,因此容易发生损伤失效.
为研究高速列车在风沙环境下的安全性,首先,基于多相流中的欧拉模型理论,建立了高速列车空气动力学模型,数值计算分析了高速列车在风沙环境下不同车速、不同风速的气动特性变化规律;接着,建立高速列车的动力学模型,将风载荷值作为外加载荷作用于列车上,从而研究了风沙环境下高速列车运行的安全性;最后,参照高速列车运行安全性相关限定标准,提出不同风速下高速列车在风沙环境中的最高安全运行速度.
当轴承在工作时会出现不同的故障,这会引起振动信号的频率分布发生改变,所以故障信号的能量也会发生相应的改变.相对BEMD 能量能够反映信号在不同频段的能量分布信息,因此滚动轴承信号的相对BEMD 能量能反映轴承出现故障情况下振动信号的能量分布特征,可以作为轴承故障诊断中的特征向量.
基于ANSYS 有限元软件,采用shell63、beam189 单元并结合MPC184 技术建立了TLJ900 型架桥机板梁结合的有限元模型,采用三步识别法对TLJ900 型架桥机主梁上易损伤的中部区域裂纹损伤进行识别.
Jet and impingement flows are two fundamental fluid dynamics problems with many applications.For rarefied jet and impingement flows,we can apply them to investigate rocket plumes,spacecraft integratio
Transverse jets are common means of maneuvering spacecrafts in both continuum and rarefied atmospheres,especially for planetary entry.In this paper,the interaction between a transverse jet and the mai
The International Space Station (ISS) Program is developing a robotically-operated leak locator tool to be used externally.The tool would consist of a Residual Gas Analyzer (RGA) for partial pressure
In space environment,the free expansion of the jet from attitude/orbit control engine to the external environment results in vacuum plume which introduces plume contamination,aerodynamic force,aerodyn
Clusters of orbital thrusters are an attractive option to achieve graduated thrust levels and increased redundancy with available hardware,but the heavily under-expanded plumes of chemical attitude co
Many defence and space research organizations have been working on the development missiles and vehicles that operate in the exo-atmospheric conditions.In addition to the main rocket motor,there is al