【作者】 徐峰；

【导师】 王旭迪；

【作者基本信息】 合肥工业大学 ， 流体机械及工程， 2024， 硕士

【摘要】 在空间引力波探测装置中,作为核心载荷之一的惯性传感器的测量灵敏度要求极高。由于其复杂的空间结构和周围环境,在工作时不可避免的会有一些气体分子与检验质量发生碰撞,而且会在狭小的空间下反复发生,对检验质量产生阻尼作用,成为限制惯性传感器测量灵敏度的主要因素之一。因此,需要对惯性传感器内残余气体分子的运动特性进行研究,探究气体阻尼效应的机理,分析影响气体阻尼的具体因素。为探究残余气体运动特性,分析了无限空间下和约束空间下由气体分子碰撞产生的残余气体阻尼模型,解析出残余气体阻尼与气体分子逃逸时间之间的定量约束关系,建立了复杂结构下的惯性传感器数理模型。提取逃逸时间的核心影响因素,利用蒙特卡洛模拟技术为切入点,得到约束条件下气体分子从板间扩散出去所需的逃逸时间和碰撞次数的模拟解,并且计算出惯性传感器等效结构下的气体阻尼大小;利用空间引力波实测数据与气体分子仿真结合,推测出可能的气体分子来源以及造成实测噪声所需的分子数量。搭建一套测量狭缝响应时间的实验装置。通过测量不同气体分子的响应时间来间接反映由于气体分子种类和平均滞留时间的不同带来的影响;并且根据实验装置的结构利用COMSOL软件进行响应时间的仿真。结果表明,气体成分、滞留时间、板间异质性和角度余弦会对气体分子的平均逃逸时间产生一定影响,其中滞留时间是主要因素;水分子由于平均滞留时间较长,响应时间远大于氮气分子,约为氮气分子的数百倍。说明在惯性传感器中,水分子相对其他气体分子更加难以去除,并且可能会产生无法预估的噪声影响。更多还原

【Abstract】 In the space gravitational wave detection apparatus,the measurement sensitivity of the inertial sensor,as one of the core payloads,is required to be extremely high.Due to the complex spatial structure and surrounding environment,collisions between gas molecules and the test mass are inevitable during operation.These collisions occur repeatedly in the confined space,causing damping effects on the test mass and becoming one of the main factors limiting the measurement sensitivity of the inertial sensor.Therefore,it is necessary to study the motion characteristics of residual gas molecules inside the inertial sensor,explore the mechanism of gas damping effects,and analyze the specific factors affecting gas damping.In order to investigate the motion characteristics of the residual gas,models of residual gas damping generated by gas molecule collisions in infinite space and constrained space are analyzed.A quantitative constraint relationship between residual gas damping and gas molecule escape time is elucidated,and a mathematical model of inertial sensor under complex structures is established.The core influencing factors of escape time are extracted,and Monte Carlo simulation techniques are utilized to obtain simulation solutions for the escape time and collision frequency of gas molecules diffusing from the plates under constraint conditions.The damping size of gas under the equivalent structure of the inertial sensor is calculated.By combining actual gravitational wave measurement data with gas molecule simulations,possible sources of gas molecules and the required quantity to cause measured noise are inferred.An experimental apparatus for slit response time measurement is constructed.By measuring the response time of different gas molecules,the effects of different gas molecule types and average residence times are indirectly reflected.Additionally,response time simulations are conducted using COMSOL software based on the experimental apparatus structure.The results indicate that gas composition,residence time,plate heterogeneity,and cosine angle have certain effects on the average escape time of gas molecules,with residence time being the primary factor.Water molecules,due to their longer average residence time,exhibit significantly longer response times compared to nitrogen molecules,on the order of hundreds of times.This suggests that in inertial sensor,water molecules are more difficult to remove than other gas molecules and may generate unpredictable noise effects.更多还原