Combined Two-Dimensional Parameter and Function Estimation in Heat Transfer

传热中二维参数和函数的组合估计

• 批准号: 8813263
• 负责人: James Beck
• 金额: $ 5.5万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-09-15 至 1991-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8813263&HistoricalAwards=false
• 关键词: Combined; Two; Dimensional; Parameter; Function

The research is primarily experimental but it utilizes advanced analysis techniques for determining parameters and functions from transient measurements. Two different types of transient heat transfer experiments are to be performed and both are multi- dimensional. The first type of experiments involves the simultaneous determination of directional thermal conductivities in a fiber-epoxy composite material and its density-specific heat product. The second type involves quenching of heated spheres in cooling baths. This has application to processing of materials to improve hardness and other metallurgical properties. Both of these experiments are to be analyzed using two-dimensional inverse computer programs developed at Michigan State University; these programs incorporate a general, direct heat conduction problem solver, TOPAZ, which was developed at Lawrence Livermore Research Laboratory. Fiber-filled epoxy composites are very important advanced materials. They have special properties that make them uniquely suited for aerospace and aeronautical applications. One of the special characteristics is their strongly directional properties, including thermal conductivity. This research is to use previously-developed parameter and function estimation techniques in the analysis of two-dimensional experiments for the measurement of directional thermal conductivities. This research is important because the thermal conductivity values are needed in the intelligent curing and processing and the design of components using these materials. Directional-dependent thermal conductivity can be difficult to measure in the usual one-dimensional experiments because the specimens are frequently restricted to being quite thin for thermal testing purposes. Two-dimensional transient experiments do not have the same restrictions. Furthermore the new combined analysis and experimental techniques have the capability to open new possibilities in such tests, including in situ tests, biological materials, and advanced directional materials such as fiber-based composites and the new superconductivity materials. Some quenching experiments are also to be performed. The various experiments have the potential of advancing the theory of combined parameters and function estimation because the estimation techniques depend critically upon the measurement accuracy and errors.

这项研究主要是试验性的，但它利用先进的分析技术从瞬变测量中确定参数和功能。将进行两种不同类型的瞬变换热实验，并且都是多维的。第一类实验涉及同时测定纤维-环氧复合材料及其密度比热积中的定向导热系数。第二种类型涉及在冷水浴中加热球体的淬火。这适用于材料的加工，以提高硬度和其他冶金性能。这两个实验都将使用密歇根州立大学开发的二维逆计算机程序进行分析；这些程序包含了劳伦斯·利弗莫尔研究实验室开发的通用、直接热传导问题解算器TOPAZ。纤维填充环氧复合材料是一种非常重要的先进材料。它们具有特殊的特性，使其特别适合航空航天应用。其中一个特殊的特征是它们的强方向性，包括导热系数。本研究旨在利用先前发展的参数与函数估计技术，分析测量定向导热系数的二维实验。这项研究很重要，因为在智能固化和加工以及使用这些材料的部件设计中需要导热值。在通常的一维实验中，与方向相关的导热系数很难测量，因为为了热测试的目的，样品通常被限制为相当薄的。二维瞬变实验则没有同样的限制。此外，新的分析和实验相结合的技术有能力在这种测试中开辟新的可能性，包括现场测试、生物材料和先进的定向材料，如纤维基复合材料和新型超导材料。还需要进行一些淬火实验。各种实验有可能推进参数和函数联合估计理论，因为估计技术严重依赖于测量精度和误差。