What is the design function of the eight-character tuyere of Odyssey near-suction range hood?

Many brands of near-suction range hoods are 90 cm wide, which seems to be very suitable for the design of double stoves. However, the tuyere (the maximum diameter of effective suction port) of the smoke collection cavity is narrow, generally only 60 cm (we call it "narrow mouth"), and even some smoke collection cavities are not "bell mouth" but "parallel mouth" design. With the design of "narrow mouth" and "parallel mouth", when smoking, the wind force in the middle of the smoke collection cavity is large and the wind force on both sides is small, which affects the distribution of wind force (that is, affects the negative pressure balance) and will lead to smoke leakage. Odyssey range hood is designed with a "horn mouth", which reaches 7 1 cm at the maximum, making it more effective for smoking.