Table of Contents Author Guidelines Submit a Manuscript
International Journal of Agronomy
Volume 2014 (2014), Article ID 276926, 8 pages
http://dx.doi.org/10.1155/2014/276926
Research Article

Physical and Aerodynamic Properties of Lavender in relation to Harvest Mechanisation

1Environmental Science and Technology Department, School of Applied Science, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK
2Department of Agricultural Technology, Alexandrio Technological Educational Institute of Thessaloniki, 57400 Thessaloniki, Greece
3Technological Research Center of Thessalia, Technological Educational Institute of Larissa, 41110 Larissa, Greece
4Department of Agricultural Technology, Technological Educational Institute of Peloponnese, Antikalamos, 24100 Kalamata, Greece

Received 23 April 2014; Accepted 18 September 2014; Published 7 October 2014

Academic Editor: Othmane Merah

Copyright © 2014 Christos I. Dimitriadis et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A laboratory study evaluated the physical and aerodynamic properties of lavender cultivars in relation to the design of an improved lavender harvester that allows removal of flowers from the stem using the stripping method. The identification of the flower head adhesion, stem breakage, and aerodynamic drag forces were conducted using an Instron 1122 instrument. Measurements on five lavender cultivars at harvest moisture content showed that the overall mean flower detachment force from the stem was 11.2 N, the mean stem tensile strength was 36.7 N, and the calculated mean ultimate tensile stress of the stem was 17.3 MPa. The aerodynamic measurements showed that the drag force is related with the flower surface area. Increasing the surface area of the flower head by 93% of the “Hidcote” cultivar produced an increase in drag force of between 24.8% and 50.6% for airflow rates of 24 and 65 m s−1, respectively. The terminal velocities of the flower heads of the cultivar ranged between 4.5 and 5.9 m s−1, which results in a mean drag coefficient of 0.44. The values of drag coefficients were compatible with well-established values for the appropriate Reynolds numbers.