The Effect of Circular Turbulator on Velocity Distribution and Turbulence Intensity in a 90° Elbow Channel

Indoor thermal comfort is an important aspect of modern building design, especially in tropical countries like Indonesia. The HVAC (Heating, Ventilation, and Air Conditioning) system uses ducting for air distribution, with the elbow component playing a crucial role in directing airflow. However, the use of elbows often causes pressure drops due to separation and the formation of secondary flows. This study evaluates the effect of installing a circular turbulator (CT) on the inner radius of a 90° elbow, focusing on fluid flow characteristics, particularly turbulence intensity and velocity distribution. Numerical simulations were performed using Ansys Fluent software with variations in CT installation angles of α = 15° and α = 20° on a 90° elbow channel. The results show that CT placement can significantly increase turbulence intensity, especially on elbows with an angle of 30°, which reaches a peak turbulence of up to 26%. CT had also been shown to be effective in delaying separation and increasing the homogeneity of velocity distribution on the inner elbow side. However, its effectiveness decreases at an angle of 90°, because the CT position is too far from the bend point. Thus, CT has the potential to be an efficient solution in improving the performance of HVAC ducting systems, especially if installed at the right position and angle according to the duct configuration.