The flow down a shaft spillway, connected with tunnel, results in nonsymmetric vortex around the axis of the shaft. The greater the nonsymmetry, the greater the pressure fluctuation and random vibration of structures....The flow down a shaft spillway, connected with tunnel, results in nonsymmetric vortex around the axis of the shaft. The greater the nonsymmetry, the greater the pressure fluctuation and random vibration of structures.This paper deals with an attempt to determine the fluctuating pressure characteristics in the shaft. Stochastic theory and random time series are employed to analyse the sample function x(t) , its x(t) and x(t), and their correlations:The moments of the spectra are obtained:The fluctuating pressure characteristics are related to the non-symmetric inlet vortex. The relation between the point pressure spectra and fluctuating pressures on the shaft wall are indicated and discussed.This paper gas further into the simulated test on the framed over-flow tower and puts forward an effective proposed way. Besides the calculation in frequency domain, computation in time domain is also ueed to analyse the same structure. The vibration source and the method to remove it are found out.展开更多
控制系统机械液压产品是涡轴涡桨发动机控制指令的重要执行元件,其生产装配完成后需要使用专用试验设备进行性能调试,调试合格后方可装配发动机。由于控制系统机械液压产品结构复杂,调试过程烦琐,对试验操作人员的技术水平要求较高,须...控制系统机械液压产品是涡轴涡桨发动机控制指令的重要执行元件,其生产装配完成后需要使用专用试验设备进行性能调试,调试合格后方可装配发动机。由于控制系统机械液压产品结构复杂,调试过程烦琐,对试验操作人员的技术水平要求较高,须构建一套基于放回取样策略-极端随机树(Return Sampling Strategy-Extreme Random Tree,RSS-ERT)的智能决策系统。通过在调试过程中采集试验数据并根据产品性能反馈调试决策,降低了调试过程对试验操作人员的技术依赖,提高了调试效率。选取某型号燃油调节器进行系统功能验证,结果表明智能决策功能反馈准确,能够满足使用需求。展开更多
文摘The flow down a shaft spillway, connected with tunnel, results in nonsymmetric vortex around the axis of the shaft. The greater the nonsymmetry, the greater the pressure fluctuation and random vibration of structures.This paper deals with an attempt to determine the fluctuating pressure characteristics in the shaft. Stochastic theory and random time series are employed to analyse the sample function x(t) , its x(t) and x(t), and their correlations:The moments of the spectra are obtained:The fluctuating pressure characteristics are related to the non-symmetric inlet vortex. The relation between the point pressure spectra and fluctuating pressures on the shaft wall are indicated and discussed.This paper gas further into the simulated test on the framed over-flow tower and puts forward an effective proposed way. Besides the calculation in frequency domain, computation in time domain is also ueed to analyse the same structure. The vibration source and the method to remove it are found out.
文摘控制系统机械液压产品是涡轴涡桨发动机控制指令的重要执行元件,其生产装配完成后需要使用专用试验设备进行性能调试,调试合格后方可装配发动机。由于控制系统机械液压产品结构复杂,调试过程烦琐,对试验操作人员的技术水平要求较高,须构建一套基于放回取样策略-极端随机树(Return Sampling Strategy-Extreme Random Tree,RSS-ERT)的智能决策系统。通过在调试过程中采集试验数据并根据产品性能反馈调试决策,降低了调试过程对试验操作人员的技术依赖,提高了调试效率。选取某型号燃油调节器进行系统功能验证,结果表明智能决策功能反馈准确,能够满足使用需求。
