高速列车表面脉动压力测试传感器设计与模拟研究

发布时间：2018-04-04 08:53

本文选题：高速列车　切入点：脉动压力　出处：《西南交通大学》2017年硕士论文

【摘要】：当高速列车运行速度超过300km/h时,气动噪声将成为列车噪声的主导成分。而脉动压力是列车气动噪声形成的根本原因。高速列车表面脉动压力具有幅值低,频带宽,易受干扰等诸多特点,因而对传感器测试性能有较高的要求。微压阻式传感器具有频响及灵敏度高、结构性能好等诸多优点,目前较常使用于高速列车表面空气动力学测试。但对于测取脉动压力,其性能仍存在一定的不足。针对以上问题,本文对微压阻式传感器测试原理进行数值模拟,研究其结构性能改进方法,并对传感器进行振动、温度干扰分析,为传感器性能结构改进及测试信号误差干扰分离提供理论依据。本文以微压阻式压力传感器为分析对象,采用Solidworks建立其核心敏感元件模型,通过Ansys进行数值模拟求解,提取结果并计算电压输出,并提出了一种划分电阻的结构-电联合数值模拟方法;在分析优化传感器平膜结构的基础上,提出了传感器双岛结构以及双岛-横梁结构,并对每种结构关键特征部位尺寸进行优化设计。通过数值模拟对比分析平膜、双岛、双岛-横梁三种结构振动作用下的干扰输出;通过箱体试验测取箱体振动对气压干扰总输出,通过CFD数值模拟得到箱体振动对流场影响,通过结构数值模拟及传感器性能指标得到振动对传感器的干扰,对比分析振动干扰规律。选取温度及压力测点,对传感器温度效应进行数值模拟,分析双岛-横梁结构的热零点漂移及灵敏度漂移:通过温度试验对国产及进口传感器温度性能指标进行测试分析。对温度-振动-压力进行了耦合干扰分析;分析多因素干扰多输入单输出模型的建立方法;设计传感器阵列结构并提出了阵列测板代替风洞模型车板壁测试脉动压力的方法。结果表明:经优化传感器结构性能,最终得到一个量程为20kPa,灵敏度为32.25mv/kPa,线性度为0.293%的双岛-横梁传感器结构,能满足脉动压力的测试需求,结构薄膜尺寸为3×3×0.02mm,岛与宽梁区底面均为1.4×1.4mm。振动干扰分析,平膜结构加速度灵敏度为0.6Pa/g,双岛结构及双岛-横梁结构加速度灵敏度为4.4-4.9Pa/g,振动影响气压变化与振动趋势一致。通过箱体试验所提取振动对气压总影响大致等于箱体流场CFD模拟与传感器振动干扰之和。双岛-横梁结构温度效应数值模拟,得到其灵敏度随温度变化规律为S =-1.194× 10-6t3 + 2.206 × 10-4t2-0.01453t + 32.5,零点漂移随温度变化规律为a= 0.1474×t-1.908;MSP1015-100传感器零漂趋势与数值模拟趋势相近,8515C-15传感器零漂趋势与数值模拟相反。基于理论、数值模拟、试验相结合能有效建立多因素干扰多输入单输出模型,设计的阵列结构性能及一致性良好,能有效测取脉动压力。
[Abstract]:When the speed of high speed train exceeds 300km/h, aerodynamic noise will become the dominant component of train noise.The pulsating pressure is the fundamental cause of train aerodynamic noise formation.The high speed train surface pulsating pressure has many characteristics such as low amplitude, frequency bandwidth, easy to be interfered, and so on, so the performance of the sensor is very high.Micro-piezoresistive sensors have many advantages, such as high frequency response, high sensitivity, good structural performance and so on. At present, micro piezoresistive sensors are often used in high-speed train surface aerodynamics testing.However, the performance of pulsating pressure is still insufficient.Aiming at the above problems, the testing principle of micro-piezoresistive sensor is numerically simulated, its structure and performance are improved, and the vibration and temperature interference of the sensor are analyzed.It provides a theoretical basis for the improvement of sensor performance and the separation of signal error and interference.In this paper, the micro-piezoresistive pressure sensor is taken as the analysis object, the core sensitive element model is established by Solidworks, and the numerical simulation is carried out by Ansys, the results are extracted and the voltage output is calculated.Based on the analysis and optimization of the sensor flat membrane structure, the sensor two-island structure and the dual-island-beam structure are proposed.At the same time, the size of the key features of each structure is optimized.Through numerical simulation, the interference output of three kinds of structures, such as flat film, double island, double island and cross beam, is compared and analyzed, and the total output of box vibration to air pressure disturbance is measured by box test, and the influence of box vibration flow field is obtained by CFD numerical simulation.The vibration interference to the sensor is obtained by numerical simulation of the structure and performance index of the sensor, and the vibration disturbance law is compared and analyzed.The temperature effect of the sensor is simulated by selecting the temperature and pressure measurement points, and the thermal zero drift and sensitivity drift of the two-island-beam structure are analyzed. The temperature performance of the domestic and imported sensors is tested and analyzed by temperature test.The coupled interference analysis of temperature-vibration-pressure is carried out; the method of establishing multi-factor interference multi-input single-output model is analyzed; the sensor array structure is designed and the method of measuring fluctuating pressure by array plate instead of wind tunnel model is proposed.The results show that a two-island-beam sensor structure with a measuring range of 20 KPA, a sensitivity of 32.25 MV / KPA and a linearity of 0.293% can be obtained by optimizing the structure performance of the sensor.The size of the structure film is 3 脳 3 脳 0.02mm, and the bottom surface of the island and the wide beam area is 1.4 脳 1.4mm.Vibration disturbance analysis shows that the acceleration sensitivity of flat membrane structure is 0.6 Pa / g, and the acceleration sensitivity of double island structure and double island beam structure is 4.4-4.9 Par / g. The effect of vibration on atmospheric pressure is consistent with the vibration trend.The total effect of the vibration extracted from the box test on the air pressure is approximately equal to the sum of the CFD simulation of the flow field of the box and the vibration disturbance of the sensor.Numerical simulation of temperature effect on double-island-crossbeam structure,It is found that the sensitivity varies with temperature as S ~ (-1.194) 脳 10-6t3 _ (2.206) 脳 10-4t2-0.01453t _ (32.5), and the zero drift with temperature is a = 0.1474 脳 t-1.908 MSP1015-100 sensor. The zero drift trend of the sensor is similar to that of numerical simulation. The zero drift trend of sensor 8515C-15 is opposite to that of numerical simulation.Based on theory, numerical simulation and experiment, the multi-factor interference multi-input single-output model can be established effectively. The designed array structure has good performance and consistency, and can effectively measure the pulsating pressure.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212

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