【作者】 李清英；

【导师】 朱春玲；

【作者基本信息】 南京航空航天大学 ， 人机与环境工程， 2012， 博士

【摘要】 电脉冲除冰系统是保障飞机在结冰气象条件下安全飞行的一种机械除冰系统，它具有高效节能、稳定性好、通用性强等优点。本文采用实验与理论相结合的方法，讨论了该系统的地面基础实验、理论及其相关计算方法与设计开发过程，具体内容如下：搭建了电脉冲除冰系统地面实验台，进行了脉冲电流、磁感应强度、瞬态加速度、结构模态以及除冰实验，为系统的理论分析与相关计算方法提供了论证依据。引出了系统振动效果的两种评价指标——峰值加速度与位移有效值，并由实验测量结果分析了放电电压、电容、线圈-铝板间距、边界条件、线圈外径、导线厚度对评价指标的影响程度。简化了脉冲电路的分析模型，基于RLC电路分析理论，求解了瞬态电流函数，通过比较几组计算与实验电流曲线，得到两者峰值偏差均小于5.2%。由此提出了正弦电流函数代替实测电流以简化电路分析的思路。并研究了以衰减电频率为设计基础且以能力需求最小为目标的圆盘形脉冲线圈优化设计方法。建立了电脉冲除冰系统铝板与线圈的二维电磁涡流场分析模型，以瞬态电流为输入参量，数值求解了铝板上的磁感应强度，该值与NASACR-4175所述计算方法相比更吻合实验结果。接着分析了电脉冲除冰系统除冰激励的两种形式：基于麦克斯韦应力法求解的总电磁脉冲力与基于安培力求解的不均匀分布在铝板上的脉冲压力。通过加载不同电流曲线计算电磁脉冲压力，初步论证了利用正弦半波电流计算除冰激励的可行性。然后讨论了铝板厚度、铝板电导率、铝板-线圈间距、电流峰值与电频率对脉冲激励的影响，为电脉冲除冰系统设计除冰激励的估算提供了重要分析依据。建立了无冰层覆盖的铝板的三维结构有限元分析模型，首先研究了铝板的固有模态，所得的前四阶固有频率与实验值相比其偏差小于3.5%，说明了所建模型的正确性。以不均匀分布的脉冲压力作为除冰激励输入载荷加载在有限元分析模型上求解了铝板的瞬态响应位移，可减少近似加载总电磁力的计算误差。并通过比较不同输入载荷条件下所计算的位移曲线，发现第一个正向周期的位移曲线基本一致，且位移峰值与实验之间的偏差均在10%以内，再次论证了正弦半波电流简化分析除冰激励是可行的。然后讨论了电流大小、电频率、铝板厚度、铝板弹性模量、铝板密度、铝板长宽比对最大响应位移的影响，同时根据分析结果提出了将电频率与系统低阶固有频率按1:1的关系设计系统的思路。研究了除冰实验与除冰过程的数值模拟。通过除冰实验一方面验证了系统设计关系式的正确性，另一方面解决了除冰机理中的一个争议性问题：高加速度并不是除冰效果的直接影响因素，而形变位移更直观评价系统的除冰好坏。引入单元生死法编写了冰层失效分析程序，有效解决了传统研究中冰层不断脱落而模型不断更新的数值问题，同时得知此次分析采用vonMises最大等效应力分析法比Labeas失效准则模拟计算的除冰范围更吻合实验结果。建立了NACA系列翼型断面模型，利用冰层失效分析程序研究了不同影响因素的除冰效果，可用于指导电脉冲除冰系统的设计安装。以ANSYS为平台二次开发了电脉冲除冰系统的设计程序，包括模态分析、脉冲线圈设计、脉冲激励求解与除冰效果分析模块。通过调用程序的各个分析模块，以实验铝板与NACA0018机翼断面为比较对象，利用优化后的脉冲线圈设计参数计算所得的除冰效果明显得到了改善。本文所取得的加载电流的简化、不均匀脉冲激励的分布求解、系统设计关系式的确定、脉冲线圈的设计与优化、除冰效果分析程序与系统设计程序等研究成果，具有一定的理论与工程实用价值，可用于指导电脉冲除冰系统的设计与分析，对减少实验成本与优化设备资源具有很好地促进作用。更多还原

【Abstract】 Electro-impulse de-icing (EIDI) system is one of the mechanical de-icing systems which assurethe safety of aircrafts in icing condition. It owns the major advantages such as effectiveness, lessenergy consumption, stability, reliability, etc. Combined theoretical and experimental methods, theground-based experiment, theory with related calculation methods, and designing programdevelopment of the EIDI system are discussed in this dissertation. Specific contents are as follows:A ground-experimental platform of EIDI system is set up. The experiments as impulse current,magnetic induction, transient acceleration, structural modal and de-icing effectiveness are completed,which provide reference for theory analysis with related calculation methods. The evaluation indexeslike peak acceleration and RMS displacement are introduced. Meanwhile, the relations between theevaluation indexes and the parameters like the discharge voltage, the capacitance, thecoil-aluminum-plate gap, boundary condition, outer diameter, and the wire thickness are discussed.Based on the simplified circuit model, the transient current are solved in the RLC circuit theory.The calculated errors of the peak current are less than5.2%by comparing the calculated withexperimental current curves. Thus, the sine current function is proposed to instead of theexperimental data for simplifying the circuit. The optimization design with less energy demand ofthe impulse coil is investigated on the basis of the damped electrical frequency.A two-dimensional electromagnetic eddy current model of the aluminum plate and the coil isbuilt. The magnetic inductions are numerical simulated with the transient current as the inputparameter, which fit better with the experiment results than the calculated values in NASA CR-4175.Then, two types of de-icing excitation of the EIDI system are intensively studied, that is, the totalelectromagnetic force based on the Maxwell tress method and the nonuniform distributedelectromagnetic pressure based on the Ampere force of the aluminum plate. The feasibility of thesimplified half-sine current is preliminarily demonstrated for the obtained pressure values by loadingthe different current functions to the eddy current model. Moreover, the factors of the impulseexcitation like the thickness and the electrical conductivity of the aluminum plate, the gap betweenthe plate and the coil, the peak current, and the electrical frequency are illustrated, which providesimportant analysis base for evaluating the de-icing excitation of the EIDI system.A three-dimensional finite element model of the aluminum plate without ice layer is developed,which is proved feasibly in the structural modal analysis with the relative error of the initial fourth order natural frequency less than3.5%by comparing the calculated natural frequency with theexperimental data. Then, the nonuniform distributed pressures are applied to the model to calculatethe transient response displacement, which can reduce the error by loading the total electromagneticforce. Additionally, the first positive displacements agree well with the experimental values and thepeak errors are less than10%by loading the different de-icing excitation, which stronglydemonstrate the feasibility of using the simplified half-sine current. Moreover, the factors of themaximum response displacement are discussed like current, electrical frequency, the thickness, theelastic module, the density, and the ratio of the length and width of the aluminum plate. Meanwhile,that the relation between the electric frequency and the natural frequency is defined as1:1isproposed for designing the EIDI system.The numerical simulation and tests of the de-icing process are investigated. The designingrelation is validated by the de-icing tests. On the other hand, a controversial issue is settled for thede-icing principle of the EIDI system, that is, the great acceleration has no direct effect on thede-icing effectiveness, while the deformation displacement is more efficient cause for the de-icingresults. Then, the ice failure program is compiled in the element killing technique, which overcomesthe limitation of the ice failure without updating the model in traditional method. Comparing withthe experimental results, the von Mises yield criterion is more suitable than Labeas ice failure insimulating the de-icing process. Then, using the series section NACA wings as the model thede-icing effectiveness is simulated, which can guide the design and installation of the EIDI system.The design program is creatively proposed by further developing the ANSYS FE codes, whichincludes the modal analysis module, the impulse coil design module, the de-icing excitation solutionmodule, and the de-icing effectiveness analysis module. Selecting the modulus sequentially, thede-icing effectiveness using the aluminum plate and the section wing of NACA0018for comparisonobjects is obtained, which is greatly improved in the optimized designing coil parameters.The achievements of the dissertation such as the simplification of the current, the solution of theuneven distribution of the de-icing excitation, the definition of the design relation, the design and theoptimization of parameters of the impulse coil, the program compilation of the de-icing effectiveness,etc, have theory and engineering value. It can make benefit to the design and analysis of the EIDIsystem, which will reduce the experimental cost and optimize the allocation of resources.更多还原