Terminal Velocity of Chopped Corn Silage and Its Separate Fractions as Affected by Moisture Content

Knowledge of the aerodynamic properties of agricultural materials is needed in equip-ment design for operations such as pneumatic conveying in loading/unloading operations of corn silage into/from silos. While considerable information is available on seed grains, little is known about the aerodynamic behavior of corn (Zea mays L.) silage. In this re-search, the weighed mean terminal velocity of a sample representative of the entire bulk mass was determined using Wolf and Tatepo’s method. The terminal velocity of various particle types (leaf, stalk and corncob pieces) of chopped forage corn plants, which were kept in silo for six months, at different moisture contents (۴۰-۵۰, ۵۰-۶۰ and ۶۰-۷۰% w.b.) was also studied. The terminal velocity was determined by measuring the air velocity re-quired to suspend a particle in a vertical air stream using a wind tunnel. A ۳ ۳ factorial treatment arrangement with ۳۰ replications in a completely randomized design was used to study the effect of moisture content and particle type on the terminal velocity. The mass mean terminal velocities of the corn silage at ۴۰-۵۰, ۵۰-۶۰ and ۶۰-۷۰% moisture con-tents were ۷.۱, ۷.۳ and ۷.۸ m/s, respectively. The results showed that only the effect of par-ticle type on the terminal velocity of corn silage was significant. The mean values of the terminal velocity of corn leaf, stalk and cob pieces were ۳.۸, ۶.۸ and ۸.۸ m/s, respectively. For each particle type at a given moisture content, the terminal velocity was best de-scribed by means of the equation of velocity squared in terms of weight.

کلیدواژه ها:

Corn ، Corncob ، Leaf ، Pneumatic conveying ، Silage ، Stalk ، Terminal velocity