论文部分内容阅读
根据热膜式气体质量-流量传感器结构特点,基于流体动力学、颗粒动力学以及传热学基本原理,建立热膜式气体质量-流量传感器流场-温度场耦合有限元模型,通过给定求解条件对热膜式流量传感器流场和温度场进行数值模拟。在求解得出流场和温度场基础上加入颗粒物离散相,用拉格朗日粒子追踪模型(DPM)追踪固相颗粒物的运动轨迹和最终状态,从而计算出粒子沉积率。在热膜芯片发热电阻加热和不加热两种情况下,研究了热泳力和布朗力对热膜芯片上颗粒物沉积的影响。得出结论:温度场对进口速度小于3 m/s、粒径小于3μm粒子在热膜芯片上的沉积有削弱作用,而对其他情况下的颗粒物粒子沉积作用影响不显著;进口速度和粒径是显著影响热膜芯片上粒子沉积的因素。
According to the characteristics of the hot-film gas mass flow sensor, a coupled finite element model of the flow field and temperature field of the hot-film gas mass flow sensor is established based on the basic principles of fluid dynamics, particle dynamics and heat transfer. Conditions for the flow field and temperature field of the hot film flow sensor are numerically simulated. Particle dispersed phase was added to solve the flow field and temperature field. Particle deposition rate was calculated by tracing the movement trajectory and the final state of solid particles with Lagrange particle tracking model (DPM). The effects of thermophoretic force and Brownian force on the deposition of particulate matter on the hot film chip were investigated in the case of heating and non-heating of the hot film chip heating resistor. It is concluded that the temperature field is less than 3 m / s for the inlet velocity and the particle size less than 3 μm has a weakening effect on the deposition of the hot film chip, but has no significant effect on the particle deposition in other cases. The inlet velocity and particle size Is a significant factor affecting the deposition of particles on the hot film chip.