气溶胶采样头在无人机上安装位置的模拟

Numerical simulation of the optimal placement of aerosol sampling-head on an unmanned aerial vehicle

利用流体力学软件CFD对固定翼无人机在海拔1000m高处以30m/s速度飞行时采样头的最佳安装位置进行了模拟.首先利用ICEM CFD前处理软件对无人机模型进行了网格划分；然后利用FLUENT软件及其中的DPM模型先后对气相（连续相）和颗粒相（离散相）分别进行了数值模拟,最后用DPM模型模拟了从速度入口方向以30m/s速度释放粒径为1,2.5,10μm的颗粒物,由颗粒物的轨迹图得到了颗粒物在机身周围的阴影区和密集区厚度.得到主要结论如下：对于本研究中的无人机,在海拔1000m高处,采集PM1,PM2.5,PM10时的气溶胶采样头的最佳安装位置为机身下部距机头距离约42～75cm,采样头探头距机身下部壁面的距离分别应大于4,4,4.3cm,但不超过26cm（机身下部距地面距离）.

CFD software was applied to simulate the optimal placement of fixed-wing UAV which flew at the altitude of 1km with a speed of 30m/s. Mesh generation was carried out for the UAV model via the pre-processing software ICEM CFD. Furthermore, the FLUENT software and the DPM model in it were used for simulating the gas phase （continuous phase） and particle phase （dispersed phase）. The DPM model simulated the trajectories of particulate matters of different sizes （1,2.5,10μm） which were released from the direction of the velocity inlet at the speed of 30m/s. The simulation results provided the thickness of shadow zones and enhancement regions. The main results indicated that：for this kind of unmanned aerial vehicle （UAV） with the altitude height of 1km, the aerosol sampling-head, which was for the purposes of gathering PM1, PM2.5 and PM10 should be installed on the bottom of the UAV and be about 42.1cm to 75cm away from the nose. The probe of sampling head for gathering PM1, PM2.5 and PM10 should be 4, 4, 4.3cm away from the bottom, respectively, but no more than 26cm.