Computational Fluid Dynamics Study of Flow within a Double Gap Cylinder

Drag reduction is a field that has been focused on these days, especially in certain fields like the oil and gas industry. Drag reduction agents are used to assist in drag reduction. To analyse the performance of drag reduction agents, rheometers with the double gap cylinder designs are preferred. However, the usage of double gap cylinder in assessing drag reduction has been slightly inaccurate. This is due to a secondary flow formed in the instrument during the assessment, which cause overflow of the fluid when the rotor is rotated up to a certain speed. This secondary flow is closely related to Taylor-Couette flow. Thus, the objective of this study is to investigate the flow behaviour of the fluid in the double concentric cylinder under specific parameters chosen. In order to do so, computational fluid dynamics would be used to the study the flow. Simulation is done using ANSYS Fluent. The geometry model is constructed and exported into Fluent, prior to the appropriate solution setups. Results were analysed though contour of velocity and graphs as well. It is found out that the instabilities starts to form in the region of angular velocities of 13-14 rad/s. Furthermore, the instabilities tend to grow with higher angular velocity applied. Results also shown that there is presence of spillage of water out from the geometry. Therefore, the instabilities in the flow that causes the secondary flow in the double gap cylinder are simulated. Nevertheless, it is recommended that simulation setup is further refined together with other parameters to be assessed further.