利用CFD模型研究苹果冷藏库内的空气流动

苹果冷藏库内的空气流动可调节库内环境,且气流速度对改善果实品质具有重要的作用,因此有必要研究苹果贮藏库内的空气流动特性。本研究采用CFD（Computational Fluid Dynamics）方法,运用大型计算流体动力学软件Fluent建立模型,以标准湍流模型对苹果冷藏库内的空气流动做三维模拟。模拟时以苹果堆码区作为多孔介质,研究库内堆码苹果时的空气流动状况,并对库内的空气流速进行试验测定和验证。结果表明,通过气流场模拟能较为直观地显示冷库内部的流场特征和流动状态,气流从风扇流出,在风机与货物堆码区形成明显的涡流;气流在货物堆码区分布较为均匀,靠近风机的货物堆码区气流速度均高于远离风机的货物堆码区气流速度。冷库流场的测量值与CFD模拟的结果进行对比,最大误差在10%以内,测量值和模拟值之间的相关系数在0.9以上,说明了CFD模拟的可靠性。该模拟结果可为商用苹果冷藏库的优化和库内环境调节提供一定的理论依据。

Airflow Simulation in Apple Cold Storage Using CFD Model

Air flow plays an important role in regulating the storehouse environment for the apple cold storage, and the velocity of air flow is significant for apple quality, therefore it is necessary to study the air flow characteristics in the apple cold storage. The Fluent software was used to establish apple cold storage model based on the computational fluid dynamics(CFD) method. The three-dimensional numerical simulation was done based on the standard turbulence model for the apple cold storage. During the simulation process, the apple stacking zone was regarded as the porous media. Air distribution and change in apple cold storage was numerically simulated and tested, and wind speed of numerical simulation was compared with that of experiment data. The results showed that, through the simulation of airflow field, it could be more intuitive to show the characteristics and state of flow field inside the cold storage. The simulation results in apple cold storage showed that an obvious vortex was formed between the fan and the stacking zone, the air flow was uniformity within them, and the air speed of stacking zone which closed to the fan was higher than the air speed of stacking zone which was far away from the fan. Compared the measurement of cold flow field and simulation results of CFD, the maximum error between them was less than 10%, the correlation coefficient was above 0.9, the analysis showed the reliability of CFD simulation. The simulation results could provide theoretical basis and environment regulation for commercial apple cold storage.