The method of calculating cut length for flail and double chop forage harvesters

Introduction. Many studies show that the chopped feed quality depends on the plants chopping quality. The quality of plant chopping, provided by a forage harvester, is defined by particle length distribution. It is important to find the theoretical basis of grass chopping regimes for making haylage and other kinds of feeds. The purpose of this study is to develop an algorithm and techniques to assess the quality of plant chopping based on mathematical models of chopping with the flail and double chop forage harvesters. Materials and Methods. Mathematical models of a flail type unit and double chop unit were presented and used to develop the algorithms and method of calculating the cut length distribution. Results. The algorithms and computation methods of cut length distribution were presented for a flail type unit and a double chop unit. The effect of the plant height, the height of cut, feed and the average length of cut on the mass fraction of particles within the specified ranges of lengths were investigated. Discussion and Conclusion. A flail forage harvester is not able to harvest the grass crops for making haylage with 45-75 % forage particles, the length of which is in the range from 8 mm to 19 mm. A double chop forage harvester allows harvesting the grass crops for making haylage only when auger angular velocity and/or flywheel or cylinder drum angular velocity is regulated. A double chop device can be used to chop plants for preparation of various forages if auger angular velocity and/or flywheel or cylinder drum's angular velocity is regulated.