Experimental investigation on thermal cracking and convective heat transfer characteristics of aviation kerosene RP-3 in a vertical tube under supercritical pressures

2019 ◽  
Vol 146 ◽  
pp. 106092 ◽  
Author(s):  
Si Jiao ◽  
Sufen Li ◽  
Hang Pu ◽  
Ming Dong ◽  
Yan Shang
Author(s):  
Yachao Song ◽  
Danjiao Ma ◽  
Jingzhi Zhang ◽  
Jing-xiang Chen ◽  
Songze Chen ◽  
...  

With the physical property changing dramatically, the supercritical aviation kerosene obtains unique heat transfer characteristics. In this way, it is difficult to investigate the heat transfer characteristics by normal experiment and therefore we resort to numerical analysis to address the scientific questions in this study. The project is proposed to demystify the heat transfer characteristics of supercritical aviation kerosene with CFD in 4mm inside diameter vertical circular tubes. Under the conditions of different pressures (3.5MPa-5MPa), the physical properties of the fluid are expressed in linear poly-nominal fitting including density, isobaric specific heat, thermal conductivity and viscosity. With the guidance of CFD, we analyze how the heat transfer characteristics can be affected by the value of temperature, pressure, heat flux mass velocity and so on. The result indicates: (1) In primary heating process, convective heat transfer is enhanced significantly. (2) When wall temperature surpasses the critical temperature, heat transfer can be deteriorated. (3) When the temperature continues to go up, the convective heat transfer coefficient will rise greatly again. Furthermore, the project has also compared the numerical analysis result with experimental result, which shows good agreement with each other. Hence, the validation of numerical analysis of supercritical fluid is well recognized.


Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7773
Author(s):  
Qinghua Yu ◽  
Yuxiang Peng ◽  
Ciprian Constantin Negoescu ◽  
Yi Wang ◽  
Yongliang Li

The convective heat transfer behavior of supercritical nitrogen (S-N2) has played a significant role in optimizing the design of recently emerging cryogenic cold storage and recovery systems. However, studies on S-N2 heat transfer have been relatively scarce, not to mention that there is a legitimate urge for a robust numerical model to accurately predict and explain S-N2 heat transfer under various working conditions. In this paper, both experimental and numerical studies were conducted for convective heat transfer of S-N2 in a small vertical tube. The results demonstrated that the standard k-ε model performed better for predicting the key heat transfer characteristics of S-N2 than the SST k-ω model. The effects of heat flux and inlet pressure on the heat transfer characteristics under a large mass flux were evaluated. The variation mechanisms of local heat transfer performance were revealed by illustrating radial profiles of thermophysical properties and turbulent parameters of N2. It was found that the local performance variation along the flow direction was mainly determined by the radial profile of specific heat while the variation of the best local performance with the ratio of heat flux to mass flux was mainly determined by the radial profile of turbulent viscosity.


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