Abstract Large eddy simulation was applied for studying the flow and heat transfer characteristics in the rotating cavity with de-swirl nozzles. Simulations were performed at the rotational Reynolds number of 1.4 × 105 and nondimensional flow rate of 4040. Compared with vertical nozzle, de-swirl nozzle generates lower swirl ratio, pressure loss and Nusselt number. Distributions of radial velocity show that de-swirl nozzle generates lower velocity in the Ekman boundary layer, but higher velocity in the core region. In the corner region of shroud and jet, the ‘dead zone’ of coherent vortices exists for vertical nozzle. However, for de-swirl nozzle, the ‘dead zone’ disappears due to the impact of inclined injection, and accordingly, the scale of time-averaged counter-rotating vortex pair is reduced effectively. In the middle and lower sections of cavity, plenty of vortex stripes are formed both for vertical and de-swirl nozzles; however, in the Ekman layer, turbulent kinetic energy and Reynolds normal stress for vertical nozzle is much higher than de-swirl nozzle. The distributions of turbulent energy spectrum and energy integral length scale show that, for de-swirl nozzle, large-scale eddies take the dominant role in middle section, while small-scale eddies dominate the flow fields in upper and lower sections of cavity.

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带有去涡流喷嘴的旋转腔中的流动和传热：LES 研究

摘要 应用大涡模拟研究了带去涡流喷嘴的旋转腔内的流动和传热特性。模拟在 1.4 × 105 的旋转雷诺数和 4040 的无量纲流速下进行。与垂直喷嘴相比，去涡流喷嘴产生更低的涡流比、压力损失和努塞尔数。径向速度分布表明，去涡流喷嘴在 Ekman 边界层产生较低的速度，但在核心区域产生较高的速度。在护罩和射流的拐角区域，垂直喷嘴存在相干涡流的“死区”。然而，对于去涡流喷嘴，由于倾斜喷射的影响，“死区”消失了，因此，时均反向旋转涡对的规模有效地减小了。在腔体的中下部，垂直和去涡流喷嘴都形成了大量的涡流条纹；然而，在 Ekman 层，垂直喷嘴的湍流动能和雷诺法向应力远高于去涡流喷嘴。湍流能谱和能量积分长度尺度的分布表明，对于去涡流喷嘴，大尺度涡流在中段占主导地位，而小尺度涡在腔体上、下段的流场中占主导地位。