A low-resistance elbow with a bionic sawtooth guide vane in ventilation and air conditioning systems

Elbow resistance is an important part of energy consumption in ventilation and air conditioning (VAC) systems. By considering the structural characteristics of bat wings and humpback whale pectoral fins, a simplified leading edge for sawtooth guide vanes is designed. Based on the theory of fluid mechanics, the resistance reduction mechanism of the sawtooth guide vane is analyzed. The numerical calculation results show that proper sawtooth groove parameters for the guide vane can effectively reduce the elbow resistance. Compared with that for a normal guide vane, the maximum resistance can be reduced by approximately 9% with the new design. In addition, we analyze the influence of the sawtooth guide vane on the entropy production of the duct elbow and the relationship between entropy production and the resistance of the duct elbow. Finally, the resistance reduction performance of the sawtooth guide vane is verified through full-scale tests.