中文摘要：

基于光纤布拉格光栅和傅里叶热传导方程提出了一种实现复合材料圆筒结构热扩散系数测量的水热平衡法，并进行了理论分析和实验研究。当圆筒结构内部流体温度升高，由初始低温平衡状态向高温平衡状态过渡，其内部流体热量从内向外传递，由于热阻的存在，而使内外壁呈现不同的温度特性，导致内外壁温度分布呈现差异性；依此原理，利用光纤布拉格光栅温度敏感特性，获取中心波长与温度函数关系及中心波长与时间函数关系，确定圆筒结构温度分布函数；根据傅里叶一维导热方程和边界条件即可求得结构热扩散系数。实验表明，升温测量与降温测量结果具有一致性，证明了该测量方案的可行性与可靠性。该测量系统具有传感元件简单、稳定性好、可操作性强等优点，为此类圆筒结构热扩散系数测量提供了一种新颖可行的方法。

英文摘要：

Based on fiber Bragg grating and Fourier heat conduction equation, a method of water-heat is used to measure the thermal diffusivity of composite cylindrical structure, with theoretical analysis and experimental research represented. When the temperature of fluid in cylindrical structure rises, the initial low-temperature equilibrium state of cylindrical structure transits to high-temperature equilibrium state, its internal fluid heat is transmitted from inside to outside, the structure exhibits different temperature characteristics due to the thermal resistance. According to this principle, the center wavelength with temperature function relationship is obtained by experiment, followed to get the relationship between the center wavelength and time functions, the cylindrical structure temperature distribution function is conclude. Based on the Fourier one dimensional heat conduction equations and boundary conditions, the structural thermal diffusivity can be obtained. Result shows that the cylindrical structure thermaldiffusion coefficient in heating and cooling process is consistent, which proves the feasibility of the measurement program. Water-heat balance method is simple, stable, operable, which provides a novel and feasible method for such cylindrical structure of the thermal diffusivity measurement.