基于ANSYS CFX的棉纤维马克隆值的建模与仿真

为探究棉纤维马克隆值与棉纤维质量关系紊乱的原因,取棉纤维的平均直径和成熟度为自变量,推导棉纤维气流仪工作的原理方程。选择6种棉样进行实验,通过测量棉纤维在等压差、等密度情况下的入口流量和马克隆值,采用中段称重法和显微镜法分别测量棉纤维的线密度和成熟度,将该值与利用公式计算的流量值进行比较分析。结果表明,等压差下通过气流入口的流量值与棉纤维成熟度和直径乘积的平方大致成正比。仿照棉纤维的结构,根据直径和成熟度构造棉纤维透气性模型,利用ANSYS CFX仿真软件进行仿真。仿真结果与实验值的最大相对误差为7.92%,证明了该模型的有效性,为修正棉纤维的Kozeny-Carman常数,进一步提高计算准确率提供参考。

Modeling and simulation of cotton micronaire value based on ANSYS CFX

In order to explore the causes for the disorder between cotton fiber micronaire value and cotton fiber quality, the working principle equation of cotton fiber airflow meter was deduced by taking the average diameter and maturity of cotton fiber as independent variables. Firstly, the flow rate of cotton fiber sample and micronaire value was measured under the condition of equal pressure and density, followed by the measurement of the fineness and maturity of six different types of cotton fiber sample using mid-section weighing method and microscopy method respectively. The values were compared with the flow rate calculated using the equation. The results show that the flow through the air inlet is approximately proportional to the square of the product of maturity and diameter of cotton fibers under a constant pressure difference. The permeability model of cotton fibers was constructed by imitating the structure of cotton fibers. According to diameter and maturity, the simulation was carried out by using ANSYS CFX simulation software. The maximum relative error between simulated and experimental results is 7.92%, which proves the validity of the model. It lays a foundation for modifying the Kozeny-Carman constant of cotton fibers and for improving the accuracy of calculation.