内外环电容传感器灵敏度仿真

为设计应用于两相流相关流速测量的电容传感器，得到传感器的几何参数对其灵敏度特性的影响，利用数值方法对内外环电容传感器的灵敏度特性进行分析．利用有限元分析软件建立传感器电场的仿真模型并进行了基本仿真，采用正交实验设计方法安排仿真实验．分析结果表明，屏蔽罩长度和内管壁厚度是影响传感器相对灵敏度的主要因素，而屏蔽罩与外极板间距对检测场均匀性误差影响比较大．优选出一组传感器的结构参数，内管壁厚度3mm，外管壁厚度2mm，屏蔽罩与外极板间距3mm，对管壁相对介电常数的要求则是越接近于1越好．利用优选的结构参数进行仿真，可以得到比较好的传感器灵敏度特性，为内外环电容传感器的设计提供了理论依据．

Simulation on the Sensitivity of Inner and Outer Ring Capacitance Sensor

To design the capacitance sensor used in measuring the correlation velocity in two-phase flow and obtain the influence of the parameters of a capacitance sensor on sensitivity,the sensitivity characteristics of the inner and outer ring capacitance sensor were analyzed using numerical simulation.The infinite element model of the electrical field in the capaci-tance sensor was created using the finite element analysis software.The simulation experiment was planed using orthogonal experimental design.The result shows that the length of the shield screen and the thickness of the inner wall are the major factors which influence the relative sensitivity.The spacing between the shield screen and the outer electrode has an impor-tant effect on the homogeneous error.The optimal structural parameters of the sensor were selected,the thickness of the inner wall is 3 mm,the thickness of the outer wall is 2 mm and the spacing between the shield screen and the outer electrode is 3 mm.The relative dielectric constant of the tube wall is required to be close to 1.The simulation on the optimal structure can obtain better sensitivity,which provides theoretical basis for the design of the inner and outer ring capacitance sensor.