EFFECT OF MOISTURE CONTENT ON AERODYNAMIC PROPERTIES OF CORN SEED (ZEA MAYS)

Abstract

Knowledge of the aerodynamic properties of agricultural materials is needed in equipment design for
operations such as cleaning, separation and pneumatic conveying in loading/unloading operations of corn
seeds into/from silos. While considerable information is available on seed grains, little is known about the
aerodynamic behavior of corn seed (Zea mays L.). In this research, aerodynamic properties of corn seed at
different moisture level were determined. It was observed that moisture content has great effect on seeds
aerodynamic properties. The results showed that the terminal velocity of the corn seeds increased linearly
from 10.65 to 12.15m/s as the moisture rose from 4 to 40% (d.b) at four levels of moisture content. The
results also showed initial decrease in drag coefficient from 0.61 to 0.52 at 4 and 12% moisture content
respectively, and thereafter increases from 0.53 to 0.63 at 16 to 40% moisture content respectively, due to
the variation in the shape of the seeds as observed on the process. The experiment showed that seed drag
coefficient is independent of seed weight, but depends mainly on the shapes of the seed. It was also
observed that the seed drag force increased linearly from 1.57 to 2.85 N as the moisture increased from 4
to 40% (d.b). Linear regression model equations for aerodynamic properties and moisture content of seeds
were determined from the graph of moisture against aerodynamic properties using excel. The analysis of
variance (ANOVA) performed showed a great significant difference in aerodynamic properties at
different level of moisture content of the seeds.