Large-Eddy Simulation Study of Flow and Heat Transfer in Swirling and Non-Swirling Impinging Jets on a Semi-Cylinder Concave Target

نویسندگان

چکیده

Swirling impinging jet (SIJ) is considered as an effective means to achieve uniform cooling at high heat transfer rates, and the complex flow structure its mechanism of enhancing have attracted much attention in recent years. The large eddy simulation (LES) technique employed analyze fields swirling non-swirling emanating from a hole with four spiral straight grooves, respectively, relatively Reynolds number (Re) 16,000 small spacing H/D = 2 on concave surface flux. Firstly, this work analyzes two different sub-grid stress models, LES wall-adapting local eddy-viscosity model (WALEM) established for accurately predicting performance SIJ flat surface. field structures, spectral characteristics, time-averaged characteristics target jets are compared detail using method. results show that small-scale recirculation vortices near wall change nearby into unstable microwave state, resulting fluctuation Nusselt (Nu) wall. There stable vortex stagnation point surface, axial radial fluctuating speeds consistent temperature. With increase radius away point, main frequency temperature coincides velocity x/D 0.5. Compared 0° hole, 45° has larger speed because deflection, turbulence intensity stronger air transport capacity. slightly improved within 5–10%.

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ژورنال

عنوان ژورنال: Applied sciences

سال: 2021

ISSN: ['2076-3417']

DOI: https://doi.org/10.3390/app11157167