论文标题
在倾斜的单相天然循环系统中的传热系数上
On the heat transfer coefficient jump in tilted single-phase natural circulation systems
论文作者
论文摘要
本研究调查了倾向对浮力驱动系统的影响。空腔，自然循环环（NCL）和耦合的自然循环回路（CNCL）已被用来表示浮力驱动系统的可能类别。关于系统从一个稳定状态移动到另一个稳定状态时，对腔系统表现出热传递系数的变化有广泛的研究。本研究的主要目的是研究使用二维CFD研究在自然循环系统（例如NCL和CNCL）中是否发生类似行为。该研究确定了流动模式重排和流动方向逆转的结合，因为现象是导致传热系数跳跃的现象。还进行了3-D CFD研究，以证明现象的普遍性。 CFD研究通过文献中可用的数值和实验数据对CFD研究进行了彻底的验证。还进行了一项参数研究，以检查纵横比，瑞利数，prandtl数量以及与NCL系统平面的倾向的影响。
The present study investigates the effect of inclination on the buoyancy driven systems. A cavity, Natural Circulation Loop (NCL) and Coupled Natural Circulation Loop (CNCL) have been used to represent the possible classes of buoyancy driven systems. There are extensive studies on the cavity systems which exhibit a heat transfer coefficient jump upon the change in the inclination as the system moves from one steady state to another. The primary objective of the present study is to investigate if a similar behavior occurs in natural circulation systems such as an NCL and a CNCL, using a 2-D CFD study. The study identifies a combination of flow pattern rearrangement and flow direction reversal as the phenomena responsible for the jump in the heat transfer coefficient. A 3-D CFD study is also conducted to demonstrate the universality of the phenomena. The CFD study is validated thoroughly with the numerical and experimental data available in the literature. A parametric study is also conducted to examine the effects of the aspect ratio, Rayleigh number, Prandtl number and the inclination with the plane of the NCL system.
