首页|基于POD降维外推差分算法的热传导模型研究

基于POD降维外推差分算法的热传导模型研究

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针对一维热传导问题,基于奇异值分解和特征投影本征分解(proper orthogonal decomposition,POD)法通过提取特征模态,建立了一种极少自由度、较高精度的降维外推仿真模型.给出模型降维近似解分量的数学推导、算法过程以及误差分析,实现了温度场的快速计算.最后,通过数值例子,将 POD计算结果与有限差分法(FDM)计算结果进行了对比.结果表明:POD方法在不同的时间步长、空间步长及定解条件下,均能捕捉到传热过程的准确信息,平均计算速度比传统有限差分法计算速度提高了 200 倍,有效缩短了计算机模拟时间.考核了低阶模型的准确性,并说明了低阶方程可以定性的反映原高维系统的传热特性.同时,POD 所得结果与 FDM结果间的最大相对误差为 0.15%,满足工程计算精度要求.所提出的POD降维外推算法方案,不但扩展了POD特征空间,而且可以逐步改进数值求解步骤,弥补了POD方法的不足,验证了利用 POD 降维算法研究传热问题的可行性与有效性.对于实现复杂传热模型的高效准确的分析与仿真数值求解过程有一定的理论参考价值.
Study on Heat Conduction Model Based on POD Reduced-order Extrapolating Finite Difference Algorithm
Aiming at one-dimensional heat conduction problem,based on singular value decomposition(SVD)and proper projection decomposition(POD)method,a reduced-dimension extrapolation simulation model with few de-grees of freedom and high accuracy is established by extracting characteristic modes.Which gives the mathematical derivation,algorithm process and error analysis of the approximate solution component of model dimension reduc-tion,and realizes the rapid calculation of temperature field.Finally,a numerical example is given to compare the cal-culated results of POD with those of finite difference method(FDM).Results show that the POD method can cap-ture accurate information about the heat transfer process under different time steps,spatial steps,and solution condi-tions.The average calculation speed is 200 times faster than the traditional finite difference method,effectively short-ening the computer simulation time.It assesses the accuracy of low order models and demonstrates that low order e-quations can qualitatively reflect the heat transfer characteristics of the original high-dimensional system.Meanwhile,the maximum relative error between the results obtained from POD and FDM is 0.15%,which meets the accuracy requirements of engineering calculations,we proposed POD dimensionality reduction extrapolation method not only expands the POD feature space,but also gradually improves the numerical solution steps,making up for the short-comings of the POD method,which also verifies the feasibility and effectiveness by using the POD dimensionality re-duction algorithm to study heat transfer problems.The proposed methods and conclusions have certain theoretical reference value for achieving efficient and accurate analysis and numerical simulation of complex heat transfer models in this article.

heat conductionsingular value decompositionreduced-order extrapolatingfinite differencebasis func-tion

巴争刚、王烨、马兵善、芦远峰、赵兴杰

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兰州交通大学 环境与市政工程学院,兰州 730070

兰州交通大学 铁道车辆热工教育部重点实验室,兰州 730070

兰州理工大学,土木工程学院,兰州 730050

热传导 奇异值分解 降维外推 有限差分 基函数

国家自然科学基金甘肃省自然科学基金甘肃省高等学校产业支撑计划兰州交通大学基础研究拔尖人才培养计划

5147607321JR7RA3042023CYZC-382022JC48

2024

兰州交通大学学报
兰州交通大学

兰州交通大学学报

影响因子:0.532
ISSN:1001-4373
年,卷(期):2024.43(2)
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