{"title":"使用改进的光线跟踪法预测具有不同表面粗糙度的金属的法向光谱发射率","authors":"Shixiong Liu , Qitai Eri , Bo Kong , Yue Zhou","doi":"10.1016/j.ijthermalsci.2024.109147","DOIUrl":null,"url":null,"abstract":"<div><p>Spectral emissivity is one of the most important parameters of metal radiation, with considerable influence on heat-transfer calculations, infrared signatures, pyrometry, and other high-temperature fields. Therefore, a computational model that can accurately calculate the emissivity of metal surfaces is crucial in these fields. In this study, a modified ray-tracing method was proposed to predict the normal spectral emissivity of a rough metal surface. In contrast to other methods involving a complex refractive index, this approach uses the known spectral emissivity of smooth surfaces as an input to avoid using complex refractive index data, which are more difficult to obtain. In addition to the emissivity data of pure Co and advanced high-strength steels samples (DP980) in the literature, emissivity measurements were conducted on GH5188 superalloy with different roughness values to further verify the modified ray-tracing method. A comparison of the measurement and prediction results revealed the high accuracy of the modified ray-tracing method, with the average and maximum errors of 1.92 % and 9.49 %, respectively, which are within the applicable range. As the new method is based on a geometric optics approximation ray-tracing approach, the model is primarily applicable to short-wavelength bands. Additionally, it has been observed in practical use for cases with low roughness. Moreover, some cases with long wavelength bands that exceed the geometric approximation can still yield highly accurate predictive results. When examining the distinction among various processing methods, higher accuracy can be achieved through two-dimensional measurements of the actual surface for prediction. In contrast, simplified methods, such as using one-dimensional cross-sections or surfaces generated based on the surface roughness for the prediction, yield less precise results.</p></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":null,"pages":null},"PeriodicalIF":4.9000,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Prediction of the normal spectral emissivity of metals with different surface roughness using a modified ray-tracing method\",\"authors\":\"Shixiong Liu , Qitai Eri , Bo Kong , Yue Zhou\",\"doi\":\"10.1016/j.ijthermalsci.2024.109147\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Spectral emissivity is one of the most important parameters of metal radiation, with considerable influence on heat-transfer calculations, infrared signatures, pyrometry, and other high-temperature fields. Therefore, a computational model that can accurately calculate the emissivity of metal surfaces is crucial in these fields. In this study, a modified ray-tracing method was proposed to predict the normal spectral emissivity of a rough metal surface. In contrast to other methods involving a complex refractive index, this approach uses the known spectral emissivity of smooth surfaces as an input to avoid using complex refractive index data, which are more difficult to obtain. In addition to the emissivity data of pure Co and advanced high-strength steels samples (DP980) in the literature, emissivity measurements were conducted on GH5188 superalloy with different roughness values to further verify the modified ray-tracing method. A comparison of the measurement and prediction results revealed the high accuracy of the modified ray-tracing method, with the average and maximum errors of 1.92 % and 9.49 %, respectively, which are within the applicable range. As the new method is based on a geometric optics approximation ray-tracing approach, the model is primarily applicable to short-wavelength bands. Additionally, it has been observed in practical use for cases with low roughness. Moreover, some cases with long wavelength bands that exceed the geometric approximation can still yield highly accurate predictive results. When examining the distinction among various processing methods, higher accuracy can be achieved through two-dimensional measurements of the actual surface for prediction. In contrast, simplified methods, such as using one-dimensional cross-sections or surfaces generated based on the surface roughness for the prediction, yield less precise results.</p></div>\",\"PeriodicalId\":341,\"journal\":{\"name\":\"International Journal of Thermal Sciences\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.9000,\"publicationDate\":\"2024-05-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Thermal Sciences\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1290072924002692\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENGINEERING, MECHANICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Thermal Sciences","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1290072924002692","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
Prediction of the normal spectral emissivity of metals with different surface roughness using a modified ray-tracing method
Spectral emissivity is one of the most important parameters of metal radiation, with considerable influence on heat-transfer calculations, infrared signatures, pyrometry, and other high-temperature fields. Therefore, a computational model that can accurately calculate the emissivity of metal surfaces is crucial in these fields. In this study, a modified ray-tracing method was proposed to predict the normal spectral emissivity of a rough metal surface. In contrast to other methods involving a complex refractive index, this approach uses the known spectral emissivity of smooth surfaces as an input to avoid using complex refractive index data, which are more difficult to obtain. In addition to the emissivity data of pure Co and advanced high-strength steels samples (DP980) in the literature, emissivity measurements were conducted on GH5188 superalloy with different roughness values to further verify the modified ray-tracing method. A comparison of the measurement and prediction results revealed the high accuracy of the modified ray-tracing method, with the average and maximum errors of 1.92 % and 9.49 %, respectively, which are within the applicable range. As the new method is based on a geometric optics approximation ray-tracing approach, the model is primarily applicable to short-wavelength bands. Additionally, it has been observed in practical use for cases with low roughness. Moreover, some cases with long wavelength bands that exceed the geometric approximation can still yield highly accurate predictive results. When examining the distinction among various processing methods, higher accuracy can be achieved through two-dimensional measurements of the actual surface for prediction. In contrast, simplified methods, such as using one-dimensional cross-sections or surfaces generated based on the surface roughness for the prediction, yield less precise results.
期刊介绍:
The International Journal of Thermal Sciences is a journal devoted to the publication of fundamental studies on the physics of transfer processes in general, with an emphasis on thermal aspects and also applied research on various processes, energy systems and the environment. Articles are published in English and French, and are subject to peer review.
The fundamental subjects considered within the scope of the journal are:
* Heat and relevant mass transfer at all scales (nano, micro and macro) and in all types of material (heterogeneous, composites, biological,...) and fluid flow
* Forced, natural or mixed convection in reactive or non-reactive media
* Single or multi–phase fluid flow with or without phase change
* Near–and far–field radiative heat transfer
* Combined modes of heat transfer in complex systems (for example, plasmas, biological, geological,...)
* Multiscale modelling
The applied research topics include:
* Heat exchangers, heat pipes, cooling processes
* Transport phenomena taking place in industrial processes (chemical, food and agricultural, metallurgical, space and aeronautical, automobile industries)
* Nano–and micro–technology for energy, space, biosystems and devices
* Heat transport analysis in advanced systems
* Impact of energy–related processes on environment, and emerging energy systems
The study of thermophysical properties of materials and fluids, thermal measurement techniques, inverse methods, and the developments of experimental methods are within the scope of the International Journal of Thermal Sciences which also covers the modelling, and numerical methods applied to thermal transfer.