根据微湍流发生机理,探讨微湍流发生器内浆料悬浮液的微湍流特性和衡量指标。以纸浆为介质,通过引入合理的纸浆纤维流动假设来建立数学模型和控制方程。将微湍流强度和湍流尺度等作为目标值,提出基于计算流体动力学(CFD)数值模拟的微湍流发生器机械结构优化设计方法,并将其应用于圆变方管束型和阶梯扩散型两类结构形式,进行性能比较研究。研究结果表明:阶梯扩散型微湍流发生器的性能要优于圆变方管束型结构形式,算法和结论可用于指导微湍流发生器的具体结构优化设计。
Abstract: Based on the principle of microturbulence's genera- tion, the turbulent characteristic and parameters of the paper pulp flow inside microturbulence generators are investigated. The modeling and numerical equations of the flow medium -- paper pulp are presented via proper assumptions on the pulp flow. Considering the microturbulence intensity and scale as parameters of the cost function, the computer fluid dynamics (CFD)-based optimal method for the structural design of microturbulence generators is proposed and applied in the design of two classical structure types: round changed to square pipes, and expanded ladder pipes. The results show that the microturbulent characteristic using expanded ladder pipes generators is better than that using round changed to square pipes generators. The numerical method and the conclusion are applicable and useful for the new design of microturbulence generators.