摘要
为了提高微混合器的混合效果,减少能量损失,提出一种由对数螺旋线流道组成的被动式微混合器,该微混合器的流道由2条对数螺旋线构成,对数螺旋线极角的取值范围为0°-180°.采用CFD软件分析了该微混合器在不同雷诺数下的混合性能,雷诺数取值范围为0.2-100.0,选择层流模型进行数值模拟.结果显示,当雷诺数小于5.0时,微混合器的出口混合指标随雷诺数的增加逐渐减小;当雷诺数大于5.0时,出口混合指标随雷诺数的增加而增大.雷诺数为0.2时,微混合器的混合指标受对数螺旋线系数b2和宽度w的影响很小,此时混合指标在0.6-0.8;随着雷诺数的增加,对数螺旋线系数b2和宽度w对混合指标的影响逐渐变强.在雷诺数为50.0的情况下,当b2为0.35-0.50,w为0.05-0.13时,微混合器的混合指标较大,混合效果较好.
A passive mieromixer with logarithmic spiral channel is presented in this paper. The channel is composed of two logarithmic spiral casings, and the spiral polar angle varies from 0° to 180°. The mixing performance of the micromixer is analyzed hy simulating the laminar flow in it at Reynohts numbers between 0.2 and 100.0. The results show that the mixing index at the exit of the mixer decreases with increasing Reynolds number until the number arrives at 5.0. However, once Reynolds number is larger than 5.0, the mixing index at the exit increases with increasing Reynolds number. At a Reynolds number of 0.2, the influence of both coefficient b： and width w on the mixing performance is quite little, and the mixing index is ranged from 0.6 to 0.8. The influences of the two factors on the mixing index increase with the increase of Reynolds number. At a Reynolds number of above 50.0, and b2 = 0.35 -0.50 as well as w = 0.05 -0. 13, the mixing index is greater, suggesting the micromixer has exhibited a better performance.
出处
《排灌机械工程学报》
EI
北大核心
2014年第11期968-972,共5页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学基金资助项目(51276082)
江苏高校优势学科建设工程资助项目
关键词
微混合器
混合指标
对数螺旋线
数值模拟
micromixer
mixing index
logarithmic spiral
numerical simulation
