Abstract: The unique upward airflow field of the top outlet outdoor unit of the air conditioner adds diversity to the installation scenarios of the air conditioner. The design of the top cover grille of the external unit must meet the strength requirements such as falling, trampling, and random vibration during transportation, while also considering the air volume during operation and ensuring lean manufacturing and cost control. The top out style grille is formed by sheet metal stamping, where the number of grilles determines the blade angle and blade strength. In order to improve the strength of the grille, reduce the risk of tearing at the root of the grille, and minimize the overall airflow, simulations and measurements were conducted to investigate the effects of different numbers of grilles on airflow and structural strength. Increasing the diameter of the inner circle of the grille by 20 mm and reducing the number of grilles by 5 can reduce stress by 1/2 and increase air volume by an average of 3.5%.

Key words: Air conditioner, Top outlet, Grille strength, Airflow optimization