| 摘要: |
| 为深入理解不同类型热边界条件下碳氢燃料流动换热和裂解特性，对第三类加热边界条件下圆通道内超临界正癸烷的流动换热和热裂解特性开展了数值研究，并与等热流和等壁温加热条件下的结果进行了对比。结果表明：管内对流换热热阻的沿程变化和管道内外温差的缩小会造成不均匀的壁面热流分布和壁温分布。通过将第三类加热边界条件下的结果与等热流加热条件下的结果进行对比发现，第三类加热条件下换热恶化程度更低，最高壁面温度由1 219 K降低到1 175 K；与等壁温加热条件下的结果相比，第三类加热条件下壁面热流密度变化规律相似但变化范围和幅度更小，在加热段后半段，其转化率和压降均低于等壁温加热条件，出口处两种条件下的转化率相差约4%。 |
| 关键词: 再生冷却 碳氢燃料 流动换热 热裂解 热边界条件 |
| DOI：10.13675/j.cnki.tjjs.2306061 |
| 分类号:V312.+1 |
| 基金项目:国家自然科学基金（52106121；52122604；52306064）；天津市应用基础研究多元投入基金（21JCQNJC00720）；中央高校基本科研业务费项目中国民航大学专项（3122019083）。 |
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| Flow heat transfer and thermal cracking characterization of supercritical n-decane under type III heating boundary conditions |
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HU Xizhuo1, XU Shi1, ZHU Jianqin2, CHENG Zeyuan2
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1.College of Aeronautical Engineering ，Civil Aviation University of China，Tianjin 300300，China;2.National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics，School of Energy and Power Engineering，Beijing University of Aeronautics and Astronautics，Beijing 100191，China
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| Abstract: |
| In order to understand flow heat transfer and thermal cracking characteristics of hydrocarbon fuel under different types of thermal boundary conditions， the flow heat transfer and thermal cracking processes of supercritical n-decane in the circular channel under type III heating boundary conditions are investigated numerically and compared with those under constant heat flux and constant wall temperature heating conditions. The results show that along-tube variation of convective heat transfer resistance and reduction of temperature difference between inside and outside of the pipe will result in uneven wall heat flux distribution and wall temperature distribution. By comparing the results under type III heating boundary conditions with those under constant heat flux heating conditions， it is found that the heat transfer deterioration is lower under type III heating boundary conditions， and the maximum wall temperature is reduced from 1 219 K to 1 175 K. Compared with the results under constant wall temperature heating conditions， the change rule of the wall heat flux under type III heating boundary conditions is similar but the range and amplitude of changes are smaller， and in the second half of the heating section，the conversion rate and pressure drop are lower than those of constant wall temperature heating conditions， and the difference of the conversion rate between the two conditions at the exit is about 4%. |
| Key words: Regenerative cooling Hydrocarbon fuels Flow heat transfer Thermal cracking Thermal boundary conditions |
