He X, Karra S, Pakseresht P, Apte S V, Elghobashi S
Department of Mechanical Engineering, Oregon State University, Corvallis, OR, USA.
Mechanical and Aerospace Engineering, The Henri Samueli School of Engineering, University of California, Irvine, CA, USA.
Int J Numer Method Biomed Eng. 2018 May;34(5):e2960. doi: 10.1002/cnm.2960. Epub 2018 Feb 20.
High-fidelity, predictive fluid flow simulations of the interactions between the rising thermal plumes from forced air warming blower and the ultra-clean ventilation air in an operating room (OR) are conducted to explore whether this complex flow can impact the dispersion of squames to the surgical site. A large-eddy simulation, accurately capturing the spatiotemporal evolution of the flow in 3 dimensions together with the trajectories of squames, is performed for a realistic OR consisting of an operating table (OT), side tables, surgical lamps, medical staff, and a patient. Two cases are studied with blower-off and blower-on together with Lagrangian trajectories of 3 million squames initially placed on the floor surrounding the OT. The large-eddy simulation results show that with the blower-off, squames are quickly transported by the ventilation air away from the table and towards the exit grilles. In contrast, with the hot air blower turned on, the ventilation airflow above and below the OT is disrupted significantly. The rising thermal plumes from the hot air blower drag the squames above the OT and the side tables and then they are advected downwards toward the surgical site by the ventilation air from the ceiling. Temporal history of the number of squames reaching 4 imaginary boxes surrounding the side tables, the OT, and the patient's knee shows that several particles reach these boxes for the blower-on case.
对强制空气暖风机产生的上升热羽流与手术室（OR）中的超净通风空气之间的相互作用进行了高保真、预测性的流体流动模拟，以探究这种复杂流动是否会影响鳞屑向手术部位的扩散。针对一个由手术台（OT）、边桌、手术灯、医护人员和一名患者组成的真实手术室，进行了大涡模拟，精确捕捉了三维流动的时空演变以及鳞屑的轨迹。研究了两种情况，即关闭风机和开启风机，并结合最初放置在手术台周围地板上的300万个鳞屑的拉格朗日轨迹。大涡模拟结果表明，关闭风机时，鳞屑会被通风空气迅速从手术台运走并朝向出口格栅。相比之下，开启热空气风机时，手术台上方和下方的通风气流会受到显著干扰。热空气风机产生的上升热羽流将手术台上方和边桌上的鳞屑拖起，然后它们被来自天花板的通风空气向下平流至手术部位。到达围绕边桌、手术台和患者膝盖的4个假想盒子的鳞屑数量的时间历程表明，对于开启风机的情况，有几个颗粒到达了这些盒子。
