CAJ | 학술논문

应用大涡模拟对设置小尺度圆柱涡流发生器矩形槽道底面的流动与传热特性进行研究，小尺度圆柱涡流发生器置于湍流边界层内。分析不同间隙比对槽道流动结构、槽道底面Nusselt数、摩擦因数以及综合性能系数的影响。此外，采用大涡模拟所得槽道计算结果与前人直接数值模拟结果一致性很好，验证所采用数值方法的准确性与可靠性。研究结果表明，与未设置小尺度圆柱涡流发生器的矩形槽道相比，设置小尺度圆柱涡流发生器槽道底面的换热性能可以得到显著提高，同时其流动阻力的增加亦得到有效抑制。当间隙比为2.0时，槽道底面换热性能最佳，其Nusselt数可提高18.76%；而当间隙比为0.5时，槽道底面减阻效果最佳，摩擦因数可减小3.77%。
응용대와모의대설치소척도원주와류발생기구형조도저면적류동여전열특성진행연구，소척도원주와류발생기치우단류변계층내。분석불동간극비대조도류동결구、조도저면Nusselt수、마찰인수이급종합성능계수적영향。차외，채용대와모의소득조도계산결과여전인직접수치모의결과일치성흔호，험증소채용수치방법적준학성여가고성。연구결과표명，여미설치소척도원주와류발생기적구형조도상비，설치소척도원주와류발생기조도저면적환열성능가이득도현저제고，동시기류동조력적증가역득도유효억제。당간극비위2.0시，조도저면환열성능최가，기Nusselt수가제고18.76%；이당간극비위0.5시，조도저면감조효과최가，마찰인수가감소3.77%。
The flow and heat characteristics of the rectangle channel bottom with a small-scale circular cylinder vortex generator are numerically investigated by large eddy simulation(LES). The vortex generator is located in the turbulence boundary layer. The influence of gap ratio on the flow structure, the Nusselt number and frication coefficient of the channel bottom, and the synthesis performance coefficient is probed. In addition, the numerical channel results by applying LES are in good agreement with the precious results by direct numerical simulation, which verifies the accuracy and reliability of present numerical method. The numerical results indicate that the heat transfer performance at the bottom of channel with small-scale circular cylinder vortex generator is significantly improved and the augmentation of flow resistance is effectively suppressed, compared to that of channel without small-scale circular cylinder vortex generator. The optimal heat transfer performance is obtalned when the gap ratio is 2.0, and the Nusselt number is increased by 18.76%. When the gap ratio is 0.5, the drag reduction is the most significant of considered cases and the frication coefficient is reduced by 3.77%.