Cutting energy characteristics of Miscanthus x giganteus stems with varying oblique angle and cutting speed

Abstract

Previous studies highlighted the need to develop efficient harvesting and size reduction equipment for miscanthus. This study investigated the effect of blade oblique angles and cutting speeds on cutting energy. Cutting blade speed, before and after severing a single miscanthus stem, was used to calculate the cutting energy. The cutting energy was determined at three oblique angles and three cutting speeds. A 60° oblique angle cut required the least energy to cut miscanthus stems averaging about 7.6 J whilst a 30° oblique cut averaged 8.7 J and a straight cut averaged 10.1 J. In general, the 60° oblique cut performed best since it required average lowest specific energy (energy per unit of stem diameter) of 741.9 J m−1 at an average cutting speed of 12.9 m s−1. The specific cutting energy was directly proportional to the cutting speed and cutting energy was proportional to the stem diameter. The results indicate that optimisation of cutting speed and blade oblique angle will result in significant energy savings and increased efficiency of miscanthus harvesting machinery.