基于传热反问题的固体材料热扩散系数测算方法

对固体材料热扩散系数测算方法进行了研究。以流动的高温水作为对流换热介质，与平板状固体试样构成第三类边界条件下的非稳态传热模型，进而利用共轭梯度法研究了固体材料热扩散系数估计的反问题。参数灵敏度分析表明对热扩散系数参数估计具有可行性，然后通过数值模拟计算，讨论了待估计参数初始猜测值、对流换热系数条件、测量误差等因素对估计结果的影响。结果表明，本文提出的方法准确性和抗不适定性较好，在初始值设定与真实值差别较大、测量温度存在明显误差时，仍能保证足够的参数反演精度（相对误差<10%），而对流换热系数条件对热扩散系数反演估计结果影响也不明显。

A method for calculation of the thermal diffusivity of a solid material based on inverse heat conduction problem analysis

Methods for calculating the thermal diffusivity of solid materials have been studied in this paper.An unsteady heat transfer model in the third boundary condition was constructed,which was composed of a flat solid sample and hot water,and then the inverse problem was studied by using a conjugate gradient method for the thermal diffusivity of the solid material.Sensitivity analysis supported the feasibility of estimating the thermal diffusivity in this way,and then the influence of the initial values of the solutions of the parameters,convective heat transfer coefficient conditions,and measured errors in the inverse estimation results of thermal diffusivity are discussed.The results showed that the proposed method had good accuracy.For larger differences between the initial settled value and the real value,although the measured temperatures had significant errors,the method is still sufficiently accurate (relative error<10%).Furthermore,the convective heat transfer coefficient condition has no obvious influence on the inverse estimation results of the thermal diffusivity.