Abstract: This paper takes a double fan ultra-thin wall embedded range hood as the research object, establishes CAE models for each of the four types of range hoods with different snail shell outlet widths, applies CFD methods to simulate the entire air duct, and conducts comparative analysis of air flow, velocity field and pressure field of the internal flow path. The air volume and noise of the above four types of range hoods were compared and verified through experimental tests. The fluctuation degree was used to evaluate the performance of the wheezing under 300 Pa back pressure. The results show that when the ratio γ between the width of the worm shell outlet and the opening degree is 1.25, the requirement of no surge under 300 Pa back pressure is satisfied, and the noise performance at the same air volume is better.

Key words: Range hood, Volute outlet width, Noise, Fluctuation strength, Surge