非对称尾部形状水翼水力阻尼识别方法研究
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摘要
水力阻尼是影响流激振动幅值预测精度的关键参数,是水力机械流激振动领域研究的热点问题。非对称尾部形状水翼在涡激振动和升力的联合作用下,振动响应的平衡位置具有时变特性,采用传统自由振动衰减法获得的水力阻尼比误差大幅度增加,甚至失效。为了克服传统自由振动衰减法应用局限,本文借助双向流固耦合数值模拟方法获得流激振动响应位移,通过带通滤波结合平衡位置校准,研究了动水环境中对称和非对称尾部形状水翼水力阻尼的识别方法。结果表明,数值模拟可较准确获取低阶结构模态和尾部旋涡脱落频率,相比实验结果,低阶弯曲模态频率、低阶扭曲模态频率和15 m/s流速下脱落涡频率最大偏差分别为7.58%、2.90%和1.42%;带通滤波可消除周期性涡激振动对响应信号的影响,水力阻尼比识别偏差度从7.51%下降到1.92%;平衡位置校准方法可采用多项式拟合法、线性插值法和光滑样条曲线法,所对应的水力阻尼比识别偏差度分别为34.93%、3.53%和0.16%。工程上,可优先推荐滤波结合线性插值法,在需要高精度水力阻尼比的场合,则必须采用滤波结合光滑样条曲线法。
Hydrodynamic damping is a critical parameter that affects the prediction accuracy of the vibration amplitude induced by flow, which is a hot issue in the field of the flow induced vibration of the hydraulic machinery. Due to the comprehensive effects of vortex-induced vibration and lift,the equilibrium position of the vibration of the asymmetric trailing edge shape hydrofoil has a time-variant characteristic.Therefore, the hydrodynamic damping ratio identified by traditional logarithmic decay method may have large deviation or even invalid. In order to overcome the limitation of the traditional free vibration method,the hydrodynamic damping identification methods of the hydrofoil with symmetrical and asymmetric trailing edge shapes in moving water were studied by combining bandpass filtering and equilibrium position calibration. The vibration induced by flow was obtained by a two-way fluid-structure numerical simulation, the first-order and second-order natural frequencies in water and the vortex shedding frequencies have good agreement with the experiments. The relative deviations are 7.58%, 2.90% and 1.42%, respectively. The vortex-induced vibration was eliminated by performing bandpass filtering, and the deviations of the identified hydrodynamic damping ratio decreased from 7.51% to 1.92%. The polynomial fitting method, the linear interpolation method and the smooth spline curve method were used in the calibration of the equilibrium position, and the deviations of identified hydrodynamic damping ratio were 34.93%, 3.53% and 0.16%, respectively. In order to reduce the time consumption of the vibration data processing, the methods of coupling filter and linear interpolation are recommended in engineering. However, the method coupled filter and smooth spline curve must be employed in the cases that the high-precision hydrodynamic damping ratio are required.
Hydrodynamic damping is a critical parameter that affects the prediction accuracy of the vibration amplitude induced by flow, which is a hot issue in the field of the flow induced vibration of the hydraulic machinery. Due to the comprehensive effects of vortex-induced vibration and lift,the equilibrium position of the vibration of the asymmetric trailing edge shape hydrofoil has a time-variant characteristic.Therefore, the hydrodynamic damping ratio identified by traditional logarithmic decay method may have large deviation or even invalid. In order to overcome the limitation of the traditional free vibration method,the hydrodynamic damping identification methods of the hydrofoil with symmetrical and asymmetric trailing edge shapes in moving water were studied by combining bandpass filtering and equilibrium position calibration. The vibration induced by flow was obtained by a two-way fluid-structure numerical simulation, the first-order and second-order natural frequencies in water and the vortex shedding frequencies have good agreement with the experiments. The relative deviations are 7.58%, 2.90% and 1.42%, respectively. The vortex-induced vibration was eliminated by performing bandpass filtering, and the deviations of the identified hydrodynamic damping ratio decreased from 7.51% to 1.92%. The polynomial fitting method, the linear interpolation method and the smooth spline curve method were used in the calibration of the equilibrium position, and the deviations of identified hydrodynamic damping ratio were 34.93%, 3.53% and 0.16%, respectively. In order to reduce the time consumption of the vibration data processing, the methods of coupling filter and linear interpolation are recommended in engineering. However, the method coupled filter and smooth spline curve must be employed in the cases that the high-precision hydrodynamic damping ratio are required.
引文
[1]胡秀成,张立翔.水泵水轮机增减负荷过程三维流动特性大涡模拟分析[J].水利学报,2018,49(4):492-500.
[2] TRIVEDI C. A review on fluid structure interaction in hydraulic turbines:a focus on hydrodynamic damping[J].Engineering Failure Analysis,2017,77:1-22.
[3] D?RFLER P,SICK M,COUTU A. Flow-Induced Pulsation and Vibration in Hydroelectric Machinery[M].Springer London,2013.
[4] AUSONI P. Turbulent vortex shedding from a blunt trailing edge hydrofoil[D]. Swiss Federal Institute of Technology Lausanne,Lausanne,2009.
[5] DOMENICO D,GROTH C,WADE A,et al. Fluid structure interaction analysis:vortex shedding induced vibrations[J]. Procedia Structural Integrity,2018(8):422-432
[6] ZOBEIRI A. Effect of hydrofoil trailing edge geometry on the wake dynamic[D]. Swiss Federal Institute of Technology Lausanne,Lausanne,2012.
[7] LIAGHAT T,GUIBAULT F,ALLENBACH L,et al. Two-Way Fluid-Structure Coupling in Vibration and Damping Analysis of an Oscillating Hydrofoil[C]//Proceedings of the ASME 2014 International Mechanical Engineering Congress and Exposition. Quebec,Canada,November 14-20,2014.
[8] ROTH S,CALMON M,FARHAT M,et al. Hydrodynamic damping identification from an impulse response of a vibration blade[C]//3rd IAHR International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems. Brno,Czech Republic,October 14-16,2009.
[9] BERGAN C,SOLEMSLIE B,?STBY P,et al. Hydrodynamic damping of a fluttering hydrofoil in high-speed flows[J]. International Journal of Fluid Machinery and Systems,2018,11(2):146-153.
[10] YAO Z,WANG F,DREYER M,et al. Effect of trailing edge shape on hydrodynamic damping for a hydrofoil[J]. Journal of Fluids&Structures,2014,51:89-198.
[11] ZENG Y,YAO Z,YANG Z,et al. The prediction of hydrodynamic damping characteristics of a hydrofoil with blunt trailing edge[C]//IOP Conference Series:Earth and Environmental Science,2017,163(1):012041.
[12]周峰,赵春宇,黄震宇,等.基于时域线性插值的信号周期计算方法及误差分析[J].仪器仪表学报,2011,32(8):1724-1730.
[13]汤跃,肖妹,汤玲迪.泵性能测试曲线分段最小二乘多项式拟合算法[J].排灌机械工程学报,2017,35(9):744-748.
[14]张人会,杨军虎.基于样条曲线的水泵叶片流线控制方法[J].排灌机械工程学报,2005,23(1):7-9.
[15] ZHENG Z,LEI J. Application of theγ-Reθtransition model to simulations of the flow past a circular cylinder[J]. Flow Turbulence&Combustion,2016,97(2):401-426.
[16]黎耀军,陈俊,姚志峰,等.基于转捩SST模型的钝尾缘水翼绕流数值计算与分析[J].水利学报,2017,48(8):993-1001.
[17] LANGTRY R,MENTER F. Correlation-based transition modeling for unstructured parallelized computational fluid dynamics codes[J]. AIAA Journal,2009,47(12):2894-2906.
[18] SILVA D. Vibration:Fundamentals and Practice[M]. CRC press,2006.
[19] DEERGHA K,SWAMY M. Digital Signal Processing Theory and Practice[M]. Springer Nature Singapore Pte Ltd,2018.
[20] ZENG Y,YAO Z,GAO J,et al. Numerical investigation of added mass and hydrodynamic damping on a blunt trailing edge hydrofoil[J]. Journal of Fluids Engineering,2019,141:018102.
[2] TRIVEDI C. A review on fluid structure interaction in hydraulic turbines:a focus on hydrodynamic damping[J].Engineering Failure Analysis,2017,77:1-22.
[3] D?RFLER P,SICK M,COUTU A. Flow-Induced Pulsation and Vibration in Hydroelectric Machinery[M].Springer London,2013.
[4] AUSONI P. Turbulent vortex shedding from a blunt trailing edge hydrofoil[D]. Swiss Federal Institute of Technology Lausanne,Lausanne,2009.
[5] DOMENICO D,GROTH C,WADE A,et al. Fluid structure interaction analysis:vortex shedding induced vibrations[J]. Procedia Structural Integrity,2018(8):422-432
[6] ZOBEIRI A. Effect of hydrofoil trailing edge geometry on the wake dynamic[D]. Swiss Federal Institute of Technology Lausanne,Lausanne,2012.
[7] LIAGHAT T,GUIBAULT F,ALLENBACH L,et al. Two-Way Fluid-Structure Coupling in Vibration and Damping Analysis of an Oscillating Hydrofoil[C]//Proceedings of the ASME 2014 International Mechanical Engineering Congress and Exposition. Quebec,Canada,November 14-20,2014.
[8] ROTH S,CALMON M,FARHAT M,et al. Hydrodynamic damping identification from an impulse response of a vibration blade[C]//3rd IAHR International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems. Brno,Czech Republic,October 14-16,2009.
[9] BERGAN C,SOLEMSLIE B,?STBY P,et al. Hydrodynamic damping of a fluttering hydrofoil in high-speed flows[J]. International Journal of Fluid Machinery and Systems,2018,11(2):146-153.
[10] YAO Z,WANG F,DREYER M,et al. Effect of trailing edge shape on hydrodynamic damping for a hydrofoil[J]. Journal of Fluids&Structures,2014,51:89-198.
[11] ZENG Y,YAO Z,YANG Z,et al. The prediction of hydrodynamic damping characteristics of a hydrofoil with blunt trailing edge[C]//IOP Conference Series:Earth and Environmental Science,2017,163(1):012041.
[12]周峰,赵春宇,黄震宇,等.基于时域线性插值的信号周期计算方法及误差分析[J].仪器仪表学报,2011,32(8):1724-1730.
[13]汤跃,肖妹,汤玲迪.泵性能测试曲线分段最小二乘多项式拟合算法[J].排灌机械工程学报,2017,35(9):744-748.
[14]张人会,杨军虎.基于样条曲线的水泵叶片流线控制方法[J].排灌机械工程学报,2005,23(1):7-9.
[15] ZHENG Z,LEI J. Application of theγ-Reθtransition model to simulations of the flow past a circular cylinder[J]. Flow Turbulence&Combustion,2016,97(2):401-426.
[16]黎耀军,陈俊,姚志峰,等.基于转捩SST模型的钝尾缘水翼绕流数值计算与分析[J].水利学报,2017,48(8):993-1001.
[17] LANGTRY R,MENTER F. Correlation-based transition modeling for unstructured parallelized computational fluid dynamics codes[J]. AIAA Journal,2009,47(12):2894-2906.
[18] SILVA D. Vibration:Fundamentals and Practice[M]. CRC press,2006.
[19] DEERGHA K,SWAMY M. Digital Signal Processing Theory and Practice[M]. Springer Nature Singapore Pte Ltd,2018.
[20] ZENG Y,YAO Z,GAO J,et al. Numerical investigation of added mass and hydrodynamic damping on a blunt trailing edge hydrofoil[J]. Journal of Fluids Engineering,2019,141:018102.