Air Resistance of Chopped Forage (I)

Apparent Drag Coefficient of Forage Stem particles

Abstract

In order to find air resistance properties of chopped forage, apparent drag coefficients of stem particles were measured supporting them in a vertical wind tunnel.
When the stem axis was supported parallel with the air stream, apparent drag coefficients decreased only slightly with an increase in Reynolde numbers. when a right angle was made between the stem axis and the air stream, they increased only slightly with an increase in Reynolde numbers.
Supported in parallel, the apparent drag coefficient of the Orchard grass stem particles, 3mm in diameter and 20mm in length, was 0.689-1.138 (Re. No. 1.13×10³-3.77×10³), and supported at a right angle, it was 0.961-1.124 (Re. No. 5.8×10²-1.94×10³). Apparent drag coefficients increased as the length-to-diameter ratio of the stem increased.