环流反应器内泡状流结构的实验研究
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摘要
用热膜测速技术对化工生产中常见的装置——环流反应器内的气液两相湍流进行了实验研究。用IFA300恒温热膜风速仪以高于对应最小湍流时间尺度的分辨率精细测量了不同工况下,环流反应器内不同空间位置瞬时速度的时间序列信号。
提出用子波分析自动识别气液两相湍流中泡状流结构的能量最大准则。利用子波分析对两相湍流脉动速度信号在时域空间和频域空间同时进行分解。根据不同尺度的子波系数研究气液两相湍流脉动动能随尺度的分布,提出用子波系数多尺度能谱分析判别泡状流结构的主要特征时间尺度的能量最大准则。
根据能量最大准则,提出利用子波系数自动识别气液两相湍流中泡状流结构的条件采样方法。提取了泡状流结构的相位平均波形。并对环流反应器内泡状流结构的发生概率、平坦因子等统计量进行了讨论。对典型泡状流结构产生的机理进行了分析。
根据环流反应器内的两相速度时间序列信号计算了反应器内的液速和气含率等重要特征参数。分析了环流反应器内液速和气含率在反应中的实际状况。通过对环流反应器内液速和气含率的测定,总结出了反应器内气含率和液速的变化规律。
The gas-liquid two-phase turbulent flow in a reflux reactor, which is usually used inchemical industrial production, has been studied by constant-temperature hot-filmanemometer. The velocity time sequence of different engineering cases and places in areflux reactor has been finely measured by IFA300 constant-temperature hot-filmanemometer with resolution higher than Kolmogorov scale.
The energy maximal criterion is developed to auto-detect bubbly flow structures ofgas-liquid two-phase flow in a reflux reactor. The wavelet analysis is used to performthe study of multi-scale simultaneous characters in temporal space and multi-scaleenergy spectrum character of bubbly flow in gas-liquid two-phase turbulent flow. Thetemporal scale of bubbly flow structure in gas-liquid two-phase flow is determined byenergy maximal criterion of turbulence wavelet transform.
A conditional sampling method is developed to auto-detect bubbly flow structures ofgas-liquid two-phase flow with the energy maximal criterion. Phased-averageevolution shapes for multi-scale are extracted from the identified bubbly flowstructures. The happening probability and flatness factor of bubbly flow structures arestudied. The happening mechanism of the typical structure of bubbly flow is analyzed.
Some important parameters in gas-liquid two-phase flow such as flow velocity andgas hold-up are calculated by the velocity time sequence. The actual status of flowvelocity and gas hold-up in a reflux reactor is analyzed. Through the measurement, arule that flow velocity and gas hold-up are changed is concluded.
提出用子波分析自动识别气液两相湍流中泡状流结构的能量最大准则。利用子波分析对两相湍流脉动速度信号在时域空间和频域空间同时进行分解。根据不同尺度的子波系数研究气液两相湍流脉动动能随尺度的分布,提出用子波系数多尺度能谱分析判别泡状流结构的主要特征时间尺度的能量最大准则。
根据能量最大准则,提出利用子波系数自动识别气液两相湍流中泡状流结构的条件采样方法。提取了泡状流结构的相位平均波形。并对环流反应器内泡状流结构的发生概率、平坦因子等统计量进行了讨论。对典型泡状流结构产生的机理进行了分析。
根据环流反应器内的两相速度时间序列信号计算了反应器内的液速和气含率等重要特征参数。分析了环流反应器内液速和气含率在反应中的实际状况。通过对环流反应器内液速和气含率的测定,总结出了反应器内气含率和液速的变化规律。
The gas-liquid two-phase turbulent flow in a reflux reactor, which is usually used inchemical industrial production, has been studied by constant-temperature hot-filmanemometer. The velocity time sequence of different engineering cases and places in areflux reactor has been finely measured by IFA300 constant-temperature hot-filmanemometer with resolution higher than Kolmogorov scale.
The energy maximal criterion is developed to auto-detect bubbly flow structures ofgas-liquid two-phase flow in a reflux reactor. The wavelet analysis is used to performthe study of multi-scale simultaneous characters in temporal space and multi-scaleenergy spectrum character of bubbly flow in gas-liquid two-phase turbulent flow. Thetemporal scale of bubbly flow structure in gas-liquid two-phase flow is determined byenergy maximal criterion of turbulence wavelet transform.
A conditional sampling method is developed to auto-detect bubbly flow structures ofgas-liquid two-phase flow with the energy maximal criterion. Phased-averageevolution shapes for multi-scale are extracted from the identified bubbly flowstructures. The happening probability and flatness factor of bubbly flow structures arestudied. The happening mechanism of the typical structure of bubbly flow is analyzed.
Some important parameters in gas-liquid two-phase flow such as flow velocity andgas hold-up are calculated by the velocity time sequence. The actual status of flowvelocity and gas hold-up in a reflux reactor is analyzed. Through the measurement, arule that flow velocity and gas hold-up are changed is concluded.
引文
[1] Resch F J, Leutheusser H J and Alemu S .Bubbly two-phase flow in hydraulic pump .J .Hydraulics Div .,1974,100(HYI):137-149
[2] Serizawa A,Kataoka I,Michiyshi I. Turbulence Structure of Air-Water Bubbly Flow-Ⅰ.Measuring Techniques[J].Int. J.Mutiphase Flow,1975a,2:221~233
[3] Liu T J, Bankoff S G.. Structure of air-water bubbly flow in a vertical pipe-Ⅰ. Liquid mean velocity and turbulence measurements. Int. J. Heat Transf, 1993, 36:1049~1060
[4] Liu T J, Bankoff S G. Structure of air-water bubbly flow in a vertical pipe-Ⅱ.Void fraction, bubble velocity and bubble size distribution. Int. J. Heat Transf, 1993, 36: 1061~ 1072
[5] R.Camussi, G.Guj, Orthonormal wavelet decomposition of turbulent flows: intermittency and coherent structures [J], J. Fluid Mech. (1997), vol. 348. pp 177-199
[6] M. Farge, Wavelet transforms and their applications to turbulence [J], Annu. Review Fluid Mech.,1992,24:395-457
[7] Miguel Onorato, Roberto Camussi, Gaetano Iuso, Small scale intermittency and bursting in a turbulent channel flow, Physical Review E, Volume 61, Number 2, 1447~1454
[8] A. Arneodo, G. Grasseau & M. Holshneider, 1988 On the wavelet transform of multifractals. Phys. Rev. Lett. 61,2281-2284
[9] E. Bacry, A. Arneodo, U. Frish et al. 1989 Wavelet analysis of fully developed turbulent data and measurement of the scaling exponents. In Proc. Turbulence 89: Organized Structures and Turbulence in Fluid Mechanics, Grenoble(France),(ed. M. Lesieur & O.Metais), pp.203-215.Kluwer
[10] S. Mimouni, G. Laval, B. Scheurer, et al. 1995 Morphology of the mixing layer in the Rayleigh-Taylor instability. In Small-scall Structures in Three Dimensional Hydrodynamic and Magneto-Hydrodynamic Turbulence. (ed. V Meneguzzi & A. Pouquet). Lecture Notes in Physics. Pp.179-192. Springer
[11] Kolmogorov A N, Dissipation of energy in the locally isotropic turbulence [J]. Dokl Akad Nauk SSSR, 1941, 32(1): 19~21
[12] Kolmogorov A N, A refinement of previous hypothesis concerning the local structure of turbulence in a viscous incompressible fluid at high Reynolds number [J]. J Fluid Mech., 1962, 13(1): 82~85
[13] Shu Wei, Jiang Nan, Eddy Scale Analysis in Turbulence[J], Acta Aerodynamica Sinica, 2000, 18, supplement: 89~95 (in Chinese).舒玮、姜楠,湍流中涡的尺度 分析[J],空气动力学报,2000,18 卷,增刊:89~95
[14] Marie Farge, Nicholas Kevlahan, Valerie Perrier, Eric Goirand, Wavelet and turbulence [J], Proceedings of the IEEE, 1996, Vol.84, No. 4: 639~669
[15] King L V. On the convection of heat from small cylinders in a stream of fluid: Determination of the convection constants of small platinum wires with applications to hot-wire anemometry. Phil. Trans. Roy. Soc., 1914,A214,373-432. 北京
[16] Jiang Nan, Wang Zhen-dong, Shu Wei. The maximum energy criterion for identifying burst events in wall turbulence using wavelet analysis. Acta Mechanica Sinica, 1997, 29(4): 406~411. (in Chinese) 姜楠,王振东,舒玮. 子波分析辩识壁湍流猝发事件的能量最大准则. 力学学报.1997,29(4):406-411.
[17] 杨建,张鸣远,张超杰等. 用热膜测速仪测量水平管内气液泡状流的液相速度和紊流结构. 核动力工程,2003,24(3)260-263,280
[18] 舒玮,姜楠,湍流中涡的尺度分析,空气动力学报,2000,18 卷,增刊:9-95
[19] 姜楠,舒玮,壁湍流相干结构的辨识,实验力学,1996,11(4):494-500
[20] 姜楠,舒玮,王振东,子波分析辨识壁湍流猝发事件的能量最大准则,力学学报,1997,29(3):406-412
[21] 姜楠,子波变换在实验流体力学中的应用,流体力学实验与测量,1997,11(1):12-19
[2] Serizawa A,Kataoka I,Michiyshi I. Turbulence Structure of Air-Water Bubbly Flow-Ⅰ.Measuring Techniques[J].Int. J.Mutiphase Flow,1975a,2:221~233
[3] Liu T J, Bankoff S G.. Structure of air-water bubbly flow in a vertical pipe-Ⅰ. Liquid mean velocity and turbulence measurements. Int. J. Heat Transf, 1993, 36:1049~1060
[4] Liu T J, Bankoff S G. Structure of air-water bubbly flow in a vertical pipe-Ⅱ.Void fraction, bubble velocity and bubble size distribution. Int. J. Heat Transf, 1993, 36: 1061~ 1072
[5] R.Camussi, G.Guj, Orthonormal wavelet decomposition of turbulent flows: intermittency and coherent structures [J], J. Fluid Mech. (1997), vol. 348. pp 177-199
[6] M. Farge, Wavelet transforms and their applications to turbulence [J], Annu. Review Fluid Mech.,1992,24:395-457
[7] Miguel Onorato, Roberto Camussi, Gaetano Iuso, Small scale intermittency and bursting in a turbulent channel flow, Physical Review E, Volume 61, Number 2, 1447~1454
[8] A. Arneodo, G. Grasseau & M. Holshneider, 1988 On the wavelet transform of multifractals. Phys. Rev. Lett. 61,2281-2284
[9] E. Bacry, A. Arneodo, U. Frish et al. 1989 Wavelet analysis of fully developed turbulent data and measurement of the scaling exponents. In Proc. Turbulence 89: Organized Structures and Turbulence in Fluid Mechanics, Grenoble(France),(ed. M. Lesieur & O.Metais), pp.203-215.Kluwer
[10] S. Mimouni, G. Laval, B. Scheurer, et al. 1995 Morphology of the mixing layer in the Rayleigh-Taylor instability. In Small-scall Structures in Three Dimensional Hydrodynamic and Magneto-Hydrodynamic Turbulence. (ed. V Meneguzzi & A. Pouquet). Lecture Notes in Physics. Pp.179-192. Springer
[11] Kolmogorov A N, Dissipation of energy in the locally isotropic turbulence [J]. Dokl Akad Nauk SSSR, 1941, 32(1): 19~21
[12] Kolmogorov A N, A refinement of previous hypothesis concerning the local structure of turbulence in a viscous incompressible fluid at high Reynolds number [J]. J Fluid Mech., 1962, 13(1): 82~85
[13] Shu Wei, Jiang Nan, Eddy Scale Analysis in Turbulence[J], Acta Aerodynamica Sinica, 2000, 18, supplement: 89~95 (in Chinese).舒玮、姜楠,湍流中涡的尺度 分析[J],空气动力学报,2000,18 卷,增刊:89~95
[14] Marie Farge, Nicholas Kevlahan, Valerie Perrier, Eric Goirand, Wavelet and turbulence [J], Proceedings of the IEEE, 1996, Vol.84, No. 4: 639~669
[15] King L V. On the convection of heat from small cylinders in a stream of fluid: Determination of the convection constants of small platinum wires with applications to hot-wire anemometry. Phil. Trans. Roy. Soc., 1914,A214,373-432. 北京
[16] Jiang Nan, Wang Zhen-dong, Shu Wei. The maximum energy criterion for identifying burst events in wall turbulence using wavelet analysis. Acta Mechanica Sinica, 1997, 29(4): 406~411. (in Chinese) 姜楠,王振东,舒玮. 子波分析辩识壁湍流猝发事件的能量最大准则. 力学学报.1997,29(4):406-411.
[17] 杨建,张鸣远,张超杰等. 用热膜测速仪测量水平管内气液泡状流的液相速度和紊流结构. 核动力工程,2003,24(3)260-263,280
[18] 舒玮,姜楠,湍流中涡的尺度分析,空气动力学报,2000,18 卷,增刊:9-95
[19] 姜楠,舒玮,壁湍流相干结构的辨识,实验力学,1996,11(4):494-500
[20] 姜楠,舒玮,王振东,子波分析辨识壁湍流猝发事件的能量最大准则,力学学报,1997,29(3):406-412
[21] 姜楠,子波变换在实验流体力学中的应用,流体力学实验与测量,1997,11(1):12-19