1·The experiment shows that the noise of the fan with inclining tongue is much lower than the fan with straight tongue, but the efficiency of the fan varies unobviously with the two kinds of tongue.
通过风机倾斜蜗舌降噪的试验和分析表明，倾斜蜗舌较直蜗舌降噪效果明显，同时对效率影响也不大。