脉动流场下波壁管内质量传递强化的影响因素分析
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摘要
高效低耗的传质传热装置在生物、化工等领域里的反应器以及换热器的设计当中有着非常广泛的应用。如何在较低流速条件下获得较高的质热传递速率便成为应用中的一个突出问题。作为质热传递设备的基本单元，许多研究者对各种二维和三维流路进行了研究。相对于二维流路中定常流、脉动流以及三维流路中的定常流这些已广泛用于工程实践的成熟的研究结果，三维流路中尤其是伴有反向流的脉动流还没有详细的探究。本研究旨在立足前人的研究基础上，拟采用电化学方法和可视化法，通过实验阐明三维波壁管内脉动流动的操作参数对传递特性的影响，特别关注伴有反向流的情况。从而优化传递过程，为工程应用打基础。本文的主要内容如下：
第一章主要对前人的研究成果进行了回顾。并将国内外许多学者的研究进行总结。已有的研究表明在定常流场下二维和三维流路内的研究结果比较成熟，实验结果和数值模拟比较吻合；在脉动流场下，二维流路的研究比较充分，但三维流路的研究成果较少。
第二章主要介绍了测试系统的组成以及本研究中所用的电化学法和流动可视化法的实验设备及实验方法，其中流动可视化采用了通过光控照相机记录下的铝微粒的运动轨迹来显示流动情况的铝尘法，质量传递速率采用电化学方法。
第三章给出了实验结果。通过固定净流动雷诺数Re_s，振动分率P和振动频率St这三个操作参数中的任意两个得出另一参数对质量传递强化因子E的影响。实验结果表明质量传递强化因子E在中等净流动雷诺数下最大，而在较低和较高的净流动雷诺数下则减小；在振动分率P≤1时变化不显著，当P＞1时，在本实验的范围内随着P增加而加强；除了中等雷诺数Re_s=154.8之外，同—雷诺数下当振动分率P≤1时随着振动频率St数变化不明显，当P＞1时随着St数变化存在一峰值，不同振动分率P下的最佳St数几乎都在0.3～0.5之间。
The high efficiency heat and mass transfer devices are widely used in the fields ofbiochemical engineering, such as designs of reactor and exchanger. The problem that how obtainseffective mass transfer rates in the condition of low flow rate has been paid more and moreattention. As the basal element of heat and mass transfer devices, many investigators have devotedtheirs efforts to the studies on the channels or tubes. There are many results that have been usedinto practical engineering for steady flow and pulsatile flow in two-dimensional channels. But ithas not enough studies for pulsatile flow in the tube, in particular with reverse flow. Based on theprevious results, the present studies describe the effect of transfer characteristic on flow parametersfor pulsatile flow in the tube by means of electrochemical method and flow visualization technique.We especially focus on the conditions with reverse flow. Main contents of this dissertation are asfollows:
In chapter 1, the previous studies have been reviewed. These studies indicate that theexperimental results agree with the results numerical simulation for steady flow in the channel. Forpulsatile flow in the channel, a great deal of studies has been done. However, there are few resultsfor pulsafile flow in the tube.
In chapter 2, it introduces the experimental apparatus and various measurement techniquesapplied to the current study are given. And the flow patterns are visualized by the aluminum dustmethod. Mass transfer rates measured by the electrochemical method.
Chapter 3 describes the experimental results. The effect of the mass transfer enhancement onone of three parameter, that is Re_s, P, St, when the others are fixed is discussed. It is found thatmass transfer enhancement factor E is optimal value at the medium Reynolds number. However,there are smaller values of E at low or high Reynolds numbers. Mass transfer enhancement factoris not remarkable change at the oscillatory fraction of the flow rate P≤1. In our experimentalranges, the mass transfer enhancement factor increases with the oscillatory fraction of the flow rateat P＞1. Except for net flow Reynolds number Re_s=154.8, When P≤1, the mass transferenhancement factor is a slight variety with Strouhal number at the same Reynolds number. At P＞1,there is a peak value of Strouhal number and its value is in the range of 0.3～0.5 even for different P.
第一章主要对前人的研究成果进行了回顾。并将国内外许多学者的研究进行总结。已有的研究表明在定常流场下二维和三维流路内的研究结果比较成熟，实验结果和数值模拟比较吻合；在脉动流场下，二维流路的研究比较充分，但三维流路的研究成果较少。
第二章主要介绍了测试系统的组成以及本研究中所用的电化学法和流动可视化法的实验设备及实验方法，其中流动可视化采用了通过光控照相机记录下的铝微粒的运动轨迹来显示流动情况的铝尘法，质量传递速率采用电化学方法。
第三章给出了实验结果。通过固定净流动雷诺数Re_s，振动分率P和振动频率St这三个操作参数中的任意两个得出另一参数对质量传递强化因子E的影响。实验结果表明质量传递强化因子E在中等净流动雷诺数下最大，而在较低和较高的净流动雷诺数下则减小；在振动分率P≤1时变化不显著，当P＞1时，在本实验的范围内随着P增加而加强；除了中等雷诺数Re_s=154.8之外，同—雷诺数下当振动分率P≤1时随着振动频率St数变化不明显，当P＞1时随着St数变化存在一峰值，不同振动分率P下的最佳St数几乎都在0.3～0.5之间。
The high efficiency heat and mass transfer devices are widely used in the fields ofbiochemical engineering, such as designs of reactor and exchanger. The problem that how obtainseffective mass transfer rates in the condition of low flow rate has been paid more and moreattention. As the basal element of heat and mass transfer devices, many investigators have devotedtheirs efforts to the studies on the channels or tubes. There are many results that have been usedinto practical engineering for steady flow and pulsatile flow in two-dimensional channels. But ithas not enough studies for pulsatile flow in the tube, in particular with reverse flow. Based on theprevious results, the present studies describe the effect of transfer characteristic on flow parametersfor pulsatile flow in the tube by means of electrochemical method and flow visualization technique.We especially focus on the conditions with reverse flow. Main contents of this dissertation are asfollows:
In chapter 1, the previous studies have been reviewed. These studies indicate that theexperimental results agree with the results numerical simulation for steady flow in the channel. Forpulsatile flow in the channel, a great deal of studies has been done. However, there are few resultsfor pulsafile flow in the tube.
In chapter 2, it introduces the experimental apparatus and various measurement techniquesapplied to the current study are given. And the flow patterns are visualized by the aluminum dustmethod. Mass transfer rates measured by the electrochemical method.
Chapter 3 describes the experimental results. The effect of the mass transfer enhancement onone of three parameter, that is Re_s, P, St, when the others are fixed is discussed. It is found thatmass transfer enhancement factor E is optimal value at the medium Reynolds number. However,there are smaller values of E at low or high Reynolds numbers. Mass transfer enhancement factoris not remarkable change at the oscillatory fraction of the flow rate P≤1. In our experimentalranges, the mass transfer enhancement factor increases with the oscillatory fraction of the flow rateat P＞1. Except for net flow Reynolds number Re_s=154.8, When P≤1, the mass transferenhancement factor is a slight variety with Strouhal number at the same Reynolds number. At P＞1,there is a peak value of Strouhal number and its value is in the range of 0.3～0.5 even for different P.
引文
[1] T. Nishimura et al. Flow observations and mass transfer characteristics in symmetrical wavy-walled channels at moderate Reynolds members for steady flow [J], Int. J. Heat Mass Transfer, 1990, 33: 835—845.
[2] T. Nishimura, Y. Ohori, Y. Kawamura. Flow characteristics in a channel with symmetric wavy wall for steady flow, J. Chem. Eng. Japan, 1984, 17: 466—471.
[3] T. Nishimura. Heat and mass transfer enhancement by chaotic mixing in laminar flow, J. Chem. Eng., 1994, 2.
[4] N. K. Ghaddar, K. Z. Korczak, B. B. Mikic and A. T. Patera, Numerical investigation of incompressible flow in grooved channels. Part 1. Stability and self-sustained oscillations, J. Fluid Mech., 1986, 163: 99-127.
[5] T. Nishimura and K. Kunitsugu, Three-dimensionality of grooved channel flows at intermediate Reynolds numbers, Experiments in Fluids, 2001, 31: 34-44.
[6] T. Nishimura, H. Nakagiri and K. Kunitsugu, Flow patterns and wall shear stresses in grooved channels at intermediate Reynolds numbers, Trans. JSME, Ser B, 1996, 62: 2106— 2112.
[7] T. Nishimura, K. Kunitsugu and H. Nakagiri, Fluid mixing and local mass transfer characteristics in a grooved channel for self-sustained oscillatory flow, Trans. JSME, Ser B, 1997, 63: 1707-1712.
[8] I. J. Wygnanski, F. H. Champagne. On transition in a pipe. Part 1. The origin of Puffs and Slugs and the flow in a turbulent Slug, J. Fluid Mech., 1973, 59: 281—335.
[9] H. Shan, B. Ma, Z. Zhang et al. Direct numerical simulation of a Puff and a Slug in transitional cylindrical pipe flow, J. Fluid Mech, 1999, 387: 39—60.
[10] T. Nishimura, Y. N. Bian. Y. Masumoto, K-Kunitsutu, Fluid flow and mass transfer characteristics in a sinusoidal wavy-walled tube at moderate Reynolds numbers for steady flow, Heat and Mass Transfer, 2003, 39: 239—248.
[11] N. K. Ghaddar, K. Z. Korczak, B. B. Mikic et al .Numerical investigation of incompressible flow in grooved channels. Part 1. Stability and self-sustained oscillations, J. Fluid Mech., 1986, 163: 99—127.
[12] N. K. Ghaddar, K. Z. Korczak, B. B. Mikic et al. Numerical investigation of incompressible flow in grooved channels. Part 2. Resonance and oscillatory heat-transfer enhancement, J. Fluid Mech., 1986, 168: 541—567.
[13] A. T. Patera, B. B. Mikic. Exploiting hydrodynamic instabilities. Resonant heat transfer enhancement, Int. J. Heat Mass Transfer, 1986, 29: 1127—1138.
[14] M. Greiner. An experimental investigation of resonant heat transfer enhancement in grooved channels, Int. J. Heat Mass Transfer, 1991, 34: 1383～1391.
[15] T. Nishimura and N. Kojima, Mass transfer enhancement in a symmetric sinusoidal wavy-walled channel for pulsatile flow, Int. J. Heat Mass Transfer, 1995, 38: 1719～1731.
[16] T. Nishimura. Heat and mass transport in channels with boundary irregularities for self-sustained oscillatory flow, Trends in Heat, Mass &Momentum Transfer, 1997, 3: 65～83.
[17] P. P. Grassmann and M. Tuma, Application of the electrolytic method-Ⅱ.Mass transfer within a tube for steady, oscillatory and pulsatile flows, Int. J. Heat Mass Transfer, 1979, 22: 799～804.
[18] B. S. Lee, I.S. Kang, H. C. Lim. Chaotic mixing and mass transfer enhancement by pulsatile laminar flow in an axisymmetric wavy channel, Int. J. Heat Mass Transfer, 1999, 42: 2571～2581.
[19] T. Nishimura et al., Mass-transfer enhancement in a wavy-walled tube by imposed fluid oscillation [J]. American Institute of Chemical Engineers, 2004, 50 (4): 762～770.
[20] M. E. Ralph, Steady flow structures and pressure drops in wavy-walled tubes, J. Fluids Eng., 1987, 109: 255～261.
[21] T. Nishimura, Y. Kajimoto, Y. Kawamura. Mass transfer enhancement in channels with a wavy wall, J. Chem. Eng. Japan, 1986, 19: 142～144.
[22] T. Nishimura, Y. Ohori, Y. Kajimoto. et al. Mass transfer characteristics in a channel with symmetric wavy wall for steady flow, J. Chem. Eng. Japan, 1985,18: 550～555.
[23] T. Nishimura, Y. Yoshinaka and K. Kunitsugu, Flow patterns and oscillatory momentum transport in grooved channels for pulsatile flow, Trans. JSME, Ser B, 2000, 66: 3056～3062.
[24] T. Mizushina, The electrochemical method in transport phenomena, Reprinted from Advances in heat and mass transfer, 1971, 7: 87～159, Academic Press Inc., New York and London.
[25] 贾宝菊，林延溥，卞永宁．利用电化学方法测量正弦波壁圆管内的质量传递速率及壁面剪切应力．第十一届全国实验力学学术会议，中国，大连，2005(第2、3章)．
[26] 张兆顺，崔桂香．流体力学[M]．北京：清华大学出版社，1999．
[27] 潘文全主编，流体力学基础[M]．机械工业出版社，1982．
[2] T. Nishimura, Y. Ohori, Y. Kawamura. Flow characteristics in a channel with symmetric wavy wall for steady flow, J. Chem. Eng. Japan, 1984, 17: 466—471.
[3] T. Nishimura. Heat and mass transfer enhancement by chaotic mixing in laminar flow, J. Chem. Eng., 1994, 2.
[4] N. K. Ghaddar, K. Z. Korczak, B. B. Mikic and A. T. Patera, Numerical investigation of incompressible flow in grooved channels. Part 1. Stability and self-sustained oscillations, J. Fluid Mech., 1986, 163: 99-127.
[5] T. Nishimura and K. Kunitsugu, Three-dimensionality of grooved channel flows at intermediate Reynolds numbers, Experiments in Fluids, 2001, 31: 34-44.
[6] T. Nishimura, H. Nakagiri and K. Kunitsugu, Flow patterns and wall shear stresses in grooved channels at intermediate Reynolds numbers, Trans. JSME, Ser B, 1996, 62: 2106— 2112.
[7] T. Nishimura, K. Kunitsugu and H. Nakagiri, Fluid mixing and local mass transfer characteristics in a grooved channel for self-sustained oscillatory flow, Trans. JSME, Ser B, 1997, 63: 1707-1712.
[8] I. J. Wygnanski, F. H. Champagne. On transition in a pipe. Part 1. The origin of Puffs and Slugs and the flow in a turbulent Slug, J. Fluid Mech., 1973, 59: 281—335.
[9] H. Shan, B. Ma, Z. Zhang et al. Direct numerical simulation of a Puff and a Slug in transitional cylindrical pipe flow, J. Fluid Mech, 1999, 387: 39—60.
[10] T. Nishimura, Y. N. Bian. Y. Masumoto, K-Kunitsutu, Fluid flow and mass transfer characteristics in a sinusoidal wavy-walled tube at moderate Reynolds numbers for steady flow, Heat and Mass Transfer, 2003, 39: 239—248.
[11] N. K. Ghaddar, K. Z. Korczak, B. B. Mikic et al .Numerical investigation of incompressible flow in grooved channels. Part 1. Stability and self-sustained oscillations, J. Fluid Mech., 1986, 163: 99—127.
[12] N. K. Ghaddar, K. Z. Korczak, B. B. Mikic et al. Numerical investigation of incompressible flow in grooved channels. Part 2. Resonance and oscillatory heat-transfer enhancement, J. Fluid Mech., 1986, 168: 541—567.
[13] A. T. Patera, B. B. Mikic. Exploiting hydrodynamic instabilities. Resonant heat transfer enhancement, Int. J. Heat Mass Transfer, 1986, 29: 1127—1138.
[14] M. Greiner. An experimental investigation of resonant heat transfer enhancement in grooved channels, Int. J. Heat Mass Transfer, 1991, 34: 1383～1391.
[15] T. Nishimura and N. Kojima, Mass transfer enhancement in a symmetric sinusoidal wavy-walled channel for pulsatile flow, Int. J. Heat Mass Transfer, 1995, 38: 1719～1731.
[16] T. Nishimura. Heat and mass transport in channels with boundary irregularities for self-sustained oscillatory flow, Trends in Heat, Mass &Momentum Transfer, 1997, 3: 65～83.
[17] P. P. Grassmann and M. Tuma, Application of the electrolytic method-Ⅱ.Mass transfer within a tube for steady, oscillatory and pulsatile flows, Int. J. Heat Mass Transfer, 1979, 22: 799～804.
[18] B. S. Lee, I.S. Kang, H. C. Lim. Chaotic mixing and mass transfer enhancement by pulsatile laminar flow in an axisymmetric wavy channel, Int. J. Heat Mass Transfer, 1999, 42: 2571～2581.
[19] T. Nishimura et al., Mass-transfer enhancement in a wavy-walled tube by imposed fluid oscillation [J]. American Institute of Chemical Engineers, 2004, 50 (4): 762～770.
[20] M. E. Ralph, Steady flow structures and pressure drops in wavy-walled tubes, J. Fluids Eng., 1987, 109: 255～261.
[21] T. Nishimura, Y. Kajimoto, Y. Kawamura. Mass transfer enhancement in channels with a wavy wall, J. Chem. Eng. Japan, 1986, 19: 142～144.
[22] T. Nishimura, Y. Ohori, Y. Kajimoto. et al. Mass transfer characteristics in a channel with symmetric wavy wall for steady flow, J. Chem. Eng. Japan, 1985,18: 550～555.
[23] T. Nishimura, Y. Yoshinaka and K. Kunitsugu, Flow patterns and oscillatory momentum transport in grooved channels for pulsatile flow, Trans. JSME, Ser B, 2000, 66: 3056～3062.
[24] T. Mizushina, The electrochemical method in transport phenomena, Reprinted from Advances in heat and mass transfer, 1971, 7: 87～159, Academic Press Inc., New York and London.
[25] 贾宝菊，林延溥，卞永宁．利用电化学方法测量正弦波壁圆管内的质量传递速率及壁面剪切应力．第十一届全国实验力学学术会议，中国，大连，2005(第2、3章)．
[26] 张兆顺，崔桂香．流体力学[M]．北京：清华大学出版社，1999．
[27] 潘文全主编，流体力学基础[M]．机械工业出版社，1982．