Slit Aspect Ratio Effect on Flow Instability and Heat Transfer Characteristics of Wavy Vortex Flow

Abstract

The slit aspect ratio effect on the flow distribution, shear stress at the cylinder and heat transfer characteristics of wavy vortex flow under variable conditions was investigated by changing the rotating Reynolds number of the inner cylinder and temperature gradient between the inner and outer cylinder walls. The accuracy of numerical simulation was validated by comparing the simulation results with the experimental results. The flow field distribution in the concentric cylinder models with four slit aspect ratios was studied. The results of the wavy vortex flow indicated that the slit depth has a remarkable impact on the heat transfer process of the flow in the annulus. It can be found that the wall shear stress at the inner cylinder experiences a significant decrease with slit depth increasing. The wall shear stress at the inner cylinder of model h* = 0.75 was the largest among four models. Furthermore, jet-like flow and heat transfer enhancement became stronger as shear stress increased. The model with 0.75 slit aspect ratio had the largest heat transfer augmentation among four models.