Experimental investigation of the effect of axial wall slits on Taylor–Couette flow

Abstract

The effect of the presence of slits in the wall of the outer one of two concentric cylinders involved in creating a Taylor-Couette flow is experimentally investigated. Three models with different numbers of slits (6, 9 and 18) are used and the radius ratio and aspect ratio of the models are 0.825 and 48, respectively. The velocity fields are measured by using the digital particle image velocimetry method, and the refractive index matching technique is applied to remove image distortion. The flow regime in the Taylor-Couette flow is studied by increasing the Reynolds number. The results show that the presence of slits does not affect the laminar transition process and that the transition to turbulent Taylor vortex is accelerated as the number of slits increases.

Slit Wall Effect on the Stability of Wavy Vortex Flow

“…As found in the previous study, the slit wall has obvious effect on the flow instability, but there is little study about the slit wall effect on the wavy vortex flow regime; only Lee et al [8] measured the wavy vortex flow field in different slit models, but they only obtained the effect of slit number on critical Reynolds number from Taylor vortex flow to wavy vortex flow. Furthermore, the flow field measured by DPIV in their study was limited; because of the limitation of measuring field, the slit number effect on the vortex size cannot be obtained precisely.…”

“…From the experimental results of Lee et al [8], as the Reynolds number is within the range of 124 to 1145, wavy vortex flow will appear in plain model. In this paper, the rotation angular velocity of inner cylinder is fixed to 1.316 rad/s, and the Reynolds number is 200.…”

“…Therefore, studies of a Taylor-Couette flow considering the effect of the cylinder wall shape were necessary. Lee et al [8] studied Taylor-Couette system with different numbers of slits in the outer cylinder by using DPIV method and found that a larger number of axial slits accelerated the transition process flow wavy vortex flow to turbulent Taylor vortex flow 2 Advances in Mechanical Engineering but have no effect on the transition before wavy vortex flow. Liu et al [9] studied the slit wall effect on flow stability in Taylor vortex flow regime and found that the vortex flow expanded into the slit wall; the intensity of the vorticity and the radial velocity increased in slit model.…”

Slit Wall and Heat Transfer Effect on the Taylor Vortex Flow

“…From the experimental results of Lee [14], when the Reynolds number is within the range of 103 to 124, Taylor vortex flow will appears in plain model. In this paper, the rotation angular velocity of inner cylinder is fixed to 0.7238 rad/s, and the Reynolds number is 110.…”

“…The working fluid sodium iodide solution filled the annular gaps and the space between the outer cylinder and the enclosure box in order to avoid the light refraction effect. More details of this method can be found in the previous study by Lee [14]. During the experiment, the temperature of the inner and outer cylinders was carefully controlled to keep the imposed temperature gradients constant.…”