CIESC Journal

• 流体力学与传递现象 • 上一篇    下一篇

顺排微柱群内部层流流动特性

管宁,刘志刚,张承武   

  1. 山东省科学院能源研究所
  • 出版日期:2011-03-05 发布日期:2011-03-05

Laminar flow characteristics in in-line arranged micro-cylinder groups

  • Online:2011-03-05 Published:2011-03-05

摘要:

采用实验与数值模拟相结合的方法,研究了去离子水在低Reynolds数下流过顺排微柱群内部时的速度场、压力场以及流动阻力特性。实验测量了柱直径为0.5 mm,柱高度分别为1.00、0.75、0.50、0.25 mm的顺排微柱群的阻力系数,发现在端壁面效应的作用下,微柱群内阻力系数随柱高增加而减小,且现有关联式对实验结果预测并不理想。因此建立了三维不可压数学模型,数值模拟了柱间距分别为0.75、1.00、1.25 mm,柱高度分别为1.00、0.75、0.50、0.25 mm

Abstract:

The flow field, pressure filed and friction characteristics of laminar flow in in-line arranged micro-cylinder groups were numerically investigated using de-ionized water as working fluid at low Reynolds numbers.The friction factors in the micro-cylinder group (cylinder diameter D =0.5 mm, cylinder height H =1.00, 0.75, 0.50 and 0.25mm)were measured.It was found that the friction factor decreased with the increase of micro-cylinder height due to the end-wall effect, and the correlations available could not predict the friction characteristics very well.A 3-D model was employed to simulate the vortex distribution in the in-line micro-cylinder groups with different geometrical parameters, including the diameter (0.5 mm)and height (0.25, 0.50, 0.75, and 1.00 mm)of micro-cylinder, pitch (0.75, 1.00, and 1.25 mm), and number of rows (3, 5, 7, 9)and columns (5, 10, 15, 20)of micro-cylinder.It was found that the vortex number increased with the pitch ratio, so that the friction factor increased.The friction factor for the in-line arranged micro-cylinder group decreased with the increase of the cylinder height and the decrease of the column number, but the influence of the row number on the friction factor was negligible.A new correlation was obtained to predict the friction factor of laminar flow in the in-line arranged micro-cylinder group and the deviation of predictions from experimental results is 10%—25% at 40<Re<150.