Evaluation of CFD accuracy for the ventilation study of a naturally ventilated broiler house
Evaluation of CFD accuracy for the ventilation study of a naturally ventilated broiler house
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DOI：
10.6090/jarq.41.53
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发表时间：
2007-01-01
影响因子：
0.4
通讯作者：
Sung, Si-Heung
中科院分区：
文献类型：
--
作者：
Lee, In-Bok;Sase, Sadanori;Sung, Si-Heung
利用CFD模型，考虑自然通风肉鸡舍通风效率的均匀性、稳定性、环境因素的适宜性等因素，设计出新的通风系统。由于进行现场通风实验研究存在诸多困难，因此必须建立可靠的三维计算流体力学（CFD）模型来研究自然通风。在研究其精度之前，首先进行了风洞和粒子图像测速（PIV）测试，以找到最佳实验条件并提高PIV精度（13,15）。采用1/20比例的自然通风肉鸡舍模型，利用PIV和CFD对肉鸡舍内气流分布进行定性和定量分析。为了提高CFD计算精度，对PIV和CFD计算的肉鸡鸡舍内气流进行了比较，重点分析了鸡舍内气流分布、局部风速和湍流强度。网格密度的质量和边界条件的设计，特别是风速和湍流剖面的设计，对于获得准确的结果是非常重要的。假设PIV结果是准确的，那么使用RNG k-epsilon湍流数值模型获得的CFD结果是最准确的。采用RNG k-epsilon模型计算气流速度的平均误差为-6.2%。
Using the CFD model, a new ventilation system design will be found later taking into consideration the ventilation efficiency such as uniformity, stability, and suitability of environmental factors in a naturally ventilated broiler house. Because conducting a field experiment for the ventilation study presented so many difficulties, a reliable 3-dimentional computational fluid dynamics (CFD) model had to be developed to investigate the natural ventilation. Before investigating its accuracy, a wind tunnel and particle image velocimetry (PIV) test was initially conducted to find their best experimental conditions and improve the PIV accuracy(13,15). A 1/20 scale model of a naturally ventilated broiler house was used to get qualitative and quantitative airflow distribution in the broiler house using the PIV and CFD. To improve the CFD accuracy, the PIV and CFD computed airflows in the broiler house were compared, particularly on the distribution, local air velocity, and turbulent intensity in the house. The quality of the mesh density and the design of the boundary condition, especially the wind velocity and turbulence profiles, were found to be very important for getting accurate results. Assuming the PIV results were accurate, the most accurate CFD results were obtained when using a RNG k-epsilon turbulence numerical model. The average error of the CFD computed air velocity when using the RNG k-epsilon models was -6.2%.