دورية أكاديمية
Improvement of the Combustion Completeness of Hydrogen Jet Flames within a Mesoscale Tube under Zero Gravity
العنوان: | Improvement of the Combustion Completeness of Hydrogen Jet Flames within a Mesoscale Tube under Zero Gravity |
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المؤلفون: | Junjie Hong, Ming Zhao, Lei Liu, Qiuxiang Shi, Xi Xiao, Aiwu Fan |
المصدر: | Energies, Vol 14, Iss 15, p 4552 (2021) |
بيانات النشر: | MDPI AG, 2021. |
سنة النشر: | 2021 |
المجموعة: | LCC:Technology |
مصطلحات موضوعية: | combustion efficiency, micro-jet flame, air entrainment ratio, flame shape, flame tip opening, Technology |
الوصف: | Microjet hydrogen flames can be directly used as micro heat sources or can be applied in micro propulsion systems. In our previous study, under zero gravity and without an active air supply, the combustion completeness of hydrogen jet flames within a mesoscale tube with an inner diameter of 5 mm was very low. In this study, we were dedicated to improving the combustion efficiency by using a convergent nozzle (tilt angle was around 68°) instead of the previous straight one, and the exit diameter was 0.8 or 0.4 mm. The numerical results demonstrate that the maximum combustion efficiency in the case of d= 0.8 mm was only around 15%; however, the peak value for the case of d = 0.4 mm was around 36%. This happened because with d = 0.4 mm, the fuel jet velocity was around four times that of the d = 0.8 mm case. Hence, the negative pressure in the combustor of d = 0.4 mm decreased to a much lower level compared to that of d = 0.8 mm, which led to an enhancement of the air entrainment ratio. However, the highest combustion efficiency of d = 0.4 mm was still below 36%; therefore, a slightly larger tube or an even smaller nozzle exit diameter will be necessary for further improvements to the combustion efficiency. |
نوع الوثيقة: | article |
وصف الملف: | electronic resource |
اللغة: | English |
تدمد: | 14154552 1996-1073 |
Relation: | https://www.mdpi.com/1996-1073/14/15/4552; https://doaj.org/toc/1996-1073 |
DOI: | 10.3390/en14154552 |
URL الوصول: | https://doaj.org/article/110393699bc446db959ecc8a31982851 |
رقم الأكسشن: | edsdoj.110393699bc446db959ecc8a31982851 |
قاعدة البيانات: | Directory of Open Access Journals |
تدمد: | 14154552 19961073 |
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DOI: | 10.3390/en14154552 |