ORCID Profile
0000-0001-5067-997X
Current Organisations
University of South Australia
,
University of Adelaide
,
University of Melbourne
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Publisher: American Society of Agricultural and Biological Engineers
Date: 2019
Publisher: American Society of Agricultural and Biological Engineers
Date: 2017
Publisher: Elsevier BV
Date: 11-2019
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 05-2015
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2017
Publisher: Elsevier BV
Date: 03-2017
Publisher: Elsevier BV
Date: 02-2014
Publisher: International Society for Horticultural Science (ISHS)
Date: 10-2018
Publisher: American Society of Agricultural and Biological Engineers
Date: 2019
Publisher: Elsevier BV
Date: 1993
Publisher: MDPI AG
Date: 13-01-2023
DOI: 10.3390/AGRICULTURE13010206
Abstract: There is a rising interest amongst Australian farmers to use disc seeders due to their ability to operate in high residue conditions and at higher speeds, commonly in the range of 12 to 15 km h−1. This paper reports on developing an analytical and discrete element method (DEM) force prediction model suited to a rotating flat disc blade operating at different sweep and tilt angles. To validate the models, field experiments were carried out with a flat disc blade at two tilt angles of 0 and 20° and four sweep angles of 6, 26, 45 and 90° in sandy soil. An analytical approach was developed following an experimental investigation that showed that only the forward portion of the disc blade is actively involved in generating soil failure, while the magnitude of this active portion of the soil-disc interface varied with sweep angle. The predicted active proportions correlated well with the experimental observations. As applying different sweep angles affects the direction of soil movement relative to the disc face, the directions of the friction and resultant forces at different sweep and tilt angles were determined. The equation of soil acceleration force was adapted to account for different sweep angles. Results showed that the predicted force fits relatively well with the measured data at 90, 45 and 26° sweep angle, while the low correlation between predicted and measured force at 6° sweep angle was due to the scrubbing reaction force not accounted for in the model. Results also showed that a better coefficient of determination (R2 = 0.93) was obtained between DEM vs. test results compared to the analytical model predictions (R2 = 0.86), particularly for predicting side forces. It was found from the study that both the developed analytical approach and DEM model enabled the prediction of soil forces at different sweep and tilt angles acting on a flat disc blade, which can assist in optimising disc design to lower the specific resistance.
Publisher: Elsevier BV
Date: 11-2016
Publisher: Elsevier BV
Date: 02-2014
Publisher: Elsevier BV
Date: 2016
Publisher: American Society of Agricultural and Biological Engineers
Date: 17-07-2016
Publisher: Elsevier BV
Date: 03-2022
Publisher: Elsevier BV
Date: 03-2013
Publisher: Elsevier BV
Date: 06-2009
Publisher: Unpublished
Date: 2014
Publisher: Inderscience Publishers
Date: 2008
Publisher: MDPI AG
Date: 13-01-2023
DOI: 10.3390/AGRICULTURE13010202
Abstract: Disc seeders are commonly used in no-till farming systems, and their performance evaluation generally rely on expensive and time-consuming field experiments. Mathematical models can help speed up force-related evaluations and improve the understanding of soil-disc interactions, to assist the performance optimisation processes. Previous analytical force prediction models of disc blades have not accounted for the free rotation aspect of the disc blade. This paper develops an analytical force prediction model from the wide blade failure theory adapted to suit rotating flat disc blades operating at different sweep and tilt angles and compares predictions with Discrete Element Method (DEM) simulations. To validate the two models, experiments were performed on a remoulded sandy soil condition using a rotating flat disc set at two tilt angles of 0° and 20°, and four sweep angles of 6, 26, 45 and 90° the 3-dimensional force components of draught, vertical and side forces were measured. Results showed a higher coefficient of determination (R2 = 0.95) was obtained with analytical model predictions compared to DEM predictions (R2 = 0.85) for their agreement with the test results. It was found that both the developed analytical approach and the DEM model can be used to predict tillage forces at different sweep and tilt angles acting on a rotating flat disc blade.
Publisher: Elsevier BV
Date: 12-2014
Publisher: Informa UK Limited
Date: 16-09-2022
Publisher: Elsevier BV
Date: 2010
Publisher: Elsevier BV
Date: 07-2008
Publisher: Informa UK Limited
Date: 26-08-2019
Publisher: Walter de Gruyter GmbH
Date: 07-04-2017
Abstract: Almonds can be classified based on their shell characteristics from soft to hard shell varieties. The majority of Australian and Californian varieties have soft shell properties. Most Spanish almond varieties have hard shells. Although having a hard sealed shell protects the kernel from insect damage it affects their processability. Common commercial almond processing equipment simultaneously compresses and shears the almonds and this creates a high percentage of damaged kernels from the broken shell being forced into the kernel, particularly for hard shell varieties. This paper shows that for the soft shell variety ‘Nonpareil’ and the three hard shell varieties of ‘Marcona’, ‘Tarraco’ and ‘Vyro’ that conditioning by soaking in water and resting before processing improves the recovery of undamaged kernel when shelling using impact. The impacts were applied by feeding the almonds into a rotating impellor and throwing them onto a stationary outer wall. An effective conditioning process resulted in the kernel moisture content increasing from 6% to 14% for hard shell and to 11% for ‘Nonpareil’ varieties. The conditioning process was measured to reduce the amount of scratched, chipped and broken kernel, and hence increased the recovery of undamaged kernel. After shelling, the conditioned kernel needed to be dried back to a 6% moisture content to be suitable for storage. Hence, the industry would be able to increase its recovery of undamaged kernel by changing to an impact shelling process using suitably conditioned almonds.
Publisher: American Society of Agricultural and Biological Engineers
Date: 17-07-2016
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 05-2014
Publisher: Elsevier BV
Date: 05-2012
Publisher: Elsevier BV
Date: 08-2017
Publisher: International Society for Horticultural Science (ISHS)
Date: 10-2018
Publisher: Elsevier BV
Date: 11-2014
Publisher: Elsevier BV
Date: 12-2020
Publisher: International Journal of Agricultural and Biological Engineering (IJABE)
Date: 2018
Publisher: American Society of Agricultural and Biological Engineers
Date: 17-07-2016
Publisher: Elsevier BV
Date: 07-2018
Publisher: Elsevier BV
Date: 2020
Publisher: American Society of Agricultural and Biological Engineers
Date: 17-07-2016
Publisher: Elsevier BV
Date: 1991
Publisher: Elsevier BV
Date: 05-2018
Publisher: Elsevier BV
Date: 2015
Publisher: Elsevier BV
Date: 2015
Publisher: American Society of Agricultural and Biological Engineers
Date: 2018
Publisher: American Society of Agricultural and Biological Engineers
Date: 2018
Publisher: Elsevier BV
Date: 06-2010
No related grants have been discovered for John Fielke.