DETERMINATION OF PHYSICAL AND BIOMETRIC PROPERTIES OF ONION BULBS IN RELATION TO DESIGN OF DIGGER CUM WINDROWER

Abstract

The physical and biometric properties play vital role in design of any soil operating machine. In view of designing
the various components of digger-cum-windrower, physical and biometric properties were determined for three
varieties of onion bulbs. The critical dimensions, viz. equatorial diameter, polar diameter, thickness, geometric
mean diameter, arithmetic mean diameter, cross sectional area, shape index, bulk density, true density, weight of
bulb, angle of repose were determined. Geometric and arithmetic mean diameters were identical for all three
varieties, which could help designing soil separator effectively. The Arka Bhim was observed to be denser than
that of two other varieties. The maximum cross sectional area was recorded for both Arka Kalyan and N 53
(1.74±0.05 cm 2 and 1.75±0.07 cm 2 ) against Arka Bhim (1.50±0.04 cm 2 ). Highest values of true density and
bulk density were recorded for Arka Bhim. Shape index was under 1.5 for all the three varieties and bulb was
considered to be nearly spherical. The Arka Bhim with its maximum frictional coefficient experienced less flow
behavior. The measured properties as a whole helped optimizing design values of different components and
effective fabrication of prototype.