Deriving realistic source boundary conditions for a CFD simulation of concentrations in workroom air.
Deriving realistic source boundary conditions for a CFD simulation of concentrations in workroom air.
复制标题
导出真实的源边界条件，以对工作室空气中的浓度进行 CFD 模拟。
DOI：
10.1093/annhyg/meq091
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Salzberg,DeborahC
中科院分区：
文献类型：
--
作者：
Feigley,CharlesE;Do,ThanhH;Khan,Jamil;Lee,Emily;Schnaufer,NicholasD;Salzberg,DeborahC
计算流体动力学（CFD）越来越多地用于模拟封闭空间中空气污染物的分布，以进行暴露评估和控制，但现实边界条件的重要性往往没有得到充分认识。在生产电容器的工作室中，在16个位置收集乙酸异戊酯（IAA）的全轮班样品3天，并在供应格栅和源附近的各个点测量速度。然后，使用295 K四面体单元、k-ε湍流模型、标准壁面函数和所有标量的10− 6收敛准则，通过三维稳态CFD模拟速度和浓度场。在这里，我们证明了需要准确地表示边界条件，特别是在污染源的排放特性，并获得良好的观测和CFD结果之间的协议。每天的排放率确定从六个浓度测量在近场和一个逆风使用IAA质量平衡。排放最初表示为未稀释的IAA蒸汽，但使用计算流体动力学估计的浓度与测量的浓度有很大差异。第二组模拟使用相同的IAA排放率，但更现实的代表性的来源。这产生了良好的协议与测量值。特别注意最高工人暴露潜力的区域-在源中心的1.3 m内-通过CFD估计的空气速度和IAA浓度与测量值没有显著差异（P= 0.92和P = 0.67）。因此，仔细考虑源边界条件大大提高了与测量值的一致性。
Computational fluid dynamics (CFD) is used increasingly to simulate the distribution of airborne contaminants in enclosed spaces for exposure assessment and control, but the importance of realistic boundary conditions is often not fully appreciated. In a workroom for manufacturing capacitors, full-shift samples for isoamyl acetate (IAA) were collected for 3 days at 16 locations, and velocities were measured at supply grills and at various points near the source. Then, velocity and concentration fields were simulated by 3-dimensional steady-state CFD using 295K tetrahedral cells, the k-ε turbulence model, standard wall function, and convergence criteria of 10−6for all scalars. Here, we demonstrate the need to represent boundary conditions accurately, especially emission characteristics at the contaminant source, and to obtain good agreement between observations and CFD results. Emission rates for each day were determined from six concentrations measured in the near field and one upwind using an IAA mass balance. The emission was initially represented as undiluted IAA vapor, but the concentrations estimated using CFD differed greatly from the measured concentrations. A second set of simulations was performed using the same IAA emission rates but a more realistic representation of the source. This yielded good agreement with measured values. Paying particular attention to the region with highest worker exposure potential—within 1.3 m of the source center—the air speed and IAA concentrations estimated by CFD were not significantly different from the measured values (P= 0.92 andP= 0.67, respectively). Thus, careful consideration of source boundary conditions greatly improved agreement with the measured values.