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ISSN Print: 1940-2503
ISSN Online: 1940-2554
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ENTROPY GENERATION IN NONCOAXIAL JET COMBUSTORS
ABSTRACT
The effect of fuel vectoring (a variable fuel jet angle) on entropy generation is evaluated in this work. A broad range of fuel jet angles (0–80 deg) are considered. The performance of the standard jet flame, with coaxial fuel-air jets, is found to improve upon adjusting the direction of fuel injection. The optimum fuel jet angle is mapped as function of fuel-air equivalence ratio (FAER). The study is limited to fuel lean conditions in the range 0.2 < FAER < 1. The study is extended by considering the effects of both fuel and combustion air preheating. An optimum air preheat temperature is identified. Although no such temperature is found for fuel, it is shown that the use of high-temperature fuel is an effective approach for managing entropy generation in noncoaxial diffusion flames. Entropy generation due to heat conduction and convection, mass transfer, viscous dissipation, the chemical reactions, and thermal radiation is taken into account. The study is carried out using a computational fluid dynamics code. The model is validated against results obtained from several experimental studies.
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