The effects of sub/supercritical conditions on the spray interface characteristics of alkane fuel

ABSTRACT

Alkane fuels are widely used in engines. The spray characteristics in supercritical environments are very different than in subcritical environments, and supercritical environments significantly impact the formation of the gas mixture in the engine. In this paper, the spray images of n-heptane and n-tetradecane in subcritical (500K-2MPa) and supercritical (700K-4MPa, 800K-6MPa) environments were obtained on the constant volume spray test platform. The effects of the supercritical environment and carbon chain length of alkane fuel on spray characteristic parameters were investigated. The results showed that the carbon chain length and ambient pressure are the main factors of penetration. The ambient pressure is the main factor of the spray cone angle and the spray non-liquid layer thickness. Compared with n-heptane, in the 500K-2MPa (subcritical) environment, the cone angle of n-tetradecane was reduced by 2°, the penetration was increased by 10 mm, and the spray non-liquid layer thickness was reduced by about 1 mm. In the 800K-6MPa (supercritical) environment, the cone angle of n-tetradecane was increased by 2°, the penetration was increased by 10 mm, and the spray non-liquid layer thickness was increased by about 1.2 mm. In addition, the calculation model of alkane fuel spray penetration in sub/supercritical environments was modified and achieved 95% prediction accuracy.

KEYWORDS:

• Heptane
• Tetradecane
• Supercritical
• Spray characteristics
• Constant volume combustion bomb

Acknowledgements

We acknowledge funding from the national natural science foundation of China under grant Grant numbers: 51776089, project of natural science foundation of Jiangsu province (BK20200910), Nantong science and technology plan project (JC2021166), open project of state key laboratory of engines (Tianjin university) (K2020-12), provincial engineering research center for new energy vehicle intelligent control and simulation test technology of Sichuan (XNYQ2021-003).

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article.

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [51776089]; Natural Science Foundation of Jiangsu Province [BK20200910]; Nantong science and technology plan project [JC2021166]; open project of state key laboratory of engines, Tianjin university [K2020-12]; provincial engineering research center for new energy vehicle intelligent control and simulation test technology of Sichuan [XNYQ2021-003]

Notes on contributors

Ruina Li

Dr. Ruina Li is an associate professor at the School of Automotive and Transportation Engineering at Jiangsu University.

Yang Song

Mr. Yang Song is a master's student at the School of Automotive and Transportation Engineering, Jiangsu University.

Liang Zhang

Mr. Liang Zhang is a master's student at the School of Automotive and Transportation Engineering, Jiangsu University.

Yikai Qian

Mr. Yikai Qian is a master's student at the School of Automotive and Transportation Engineering, Jiangsu University.

Zhong Wang

Dr. Zhong Wang is a professor at the School of Automotive and Transportation Engineering, Jiangsu University.

Yiqiang Pei

Dr. Yiqiang Pei is an associate professor at the School of Mechanical Engineering at Tianjin University.

Yanzhao An

Dr. Yanzhao An is an associate professor at the School of Mechanical Engineering at Tianjin University