CFD Simulation Techniques for Optimizing Operating Torque in HVAC Kinematics

This paper presents a comprehensive overview of the methodology employed in leveraging CFD for optimizing HVAC kinematics, focusing on reducing the operating torque by improvising the flap geometry. The aim here is to utilize the CFD simulation in order to predict the torque generated on the actuator motor connected to the flap when the flap is placed in high speed airflow and based on this value work out an optimized geometry of the flap, since its geometry plays a significant role when it comes to determining the torque values. Different flap geometry imparts different torque on motor. This torque is generated because of the force acting on the flap which is acting as a buffer in the path of airflow. The torque generated should be less than the stall torque of the actuator motor in order for smooth performance/movement of the flap. Initial geometry of the flap generated a torque of around 82.5 Ncm which was much higher than the recommendation limit. So in order to bring these torque values within the working range of actuator motor, number of different iterations regarding the geometry of the flap were carried out which eventually brought the torque value to 55 Ncm which was well within the recommended torque value of the motor. Thereby approving the flap geometry. The paper also validates the simulation results with the test results. Through CFD, optimized geometry of flap is obtained without the need of employing high torque motor for its rotation thereby not increasing the overall cost of the HVAC unit.