| 摘要 |
A trawl door (20, 60) or a paravane (120, 140) having at least one main d eflector (22, 22U, 22L) includes a permeable structure disposed adjacent to and separated from an outer surface (34) of the main deflector (22, 22U, 22L ). The permeable structure extends from near a trailing edge (26, 26U, 26L) of the main deflector (22, 22U, 22L) over and separated from the outer surfa ce (34) toward the main deflector's leading edge (24, 24U, 24L). In one embo diment of the permeable structure, a plurality of apertures (54, 56) pierce a perforated slat (52, 52U, 52L) thereby establishing a porous surface adjac ent to the outer surface (34) of the main deflector (22, 22U, 22L). Adding t he permeable structure perforated slat (52, 52U, 52L) to a trawl door (20, 6 0) increases the trawl door's stability when the trawl door is towed through water at a high angle of attack, and also reduces the trawl door's drag whe n operating at a high angle of attack.
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