ORCID Profile
0000-0002-6485-5492
Current Organisation
University of Western Australia
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Applied Economics not elsewhere classified | Marketing Management (incl. Strategy and Customer Relations) | Applied Economics | Decision Making
ANZSRC Socio-Economic Objective (SEO)
Behaviour and Health | Expanding Knowledge in the Agricultural and Veterinary Sciences | Information Services not elsewhere classified |
Related Links
Publications
Flash flaming technology shows promise to improve seed-based rehabilitation outcomes
Publisher: Australian Centre for Geomechanics, Perth
Date: 2019
Some torsional stiffness and damping characteristics of a small pneumatic tyre and the implications for powertrain dynamics
Publisher: SAGE Publications
Date: 25-09-2009
DOI: 10.1243/09544070JAUTO1194
Abstract: Torsional vibration modelling of powertrains is hindered by the lack of understanding of tyre low-frequency torsional stiffness and d ing characteristics. Torsional here means rotation about the wheel (spin) axis so that the rotation of the wheel hub is different from that of the periphery of the tyre. This paper explains a simple, practical test rig design that can be used to determine a tyre's torsional characteristics via simple modelling. The model assumes a complex stiffness that allows the d ing type to be determined as a function of the frequency. The measurement of some torsional stiffness and d ing characteristics of a small pneumatic tyre while under load and rolling is presented. The tyre was excited torsionally and, from the results obtained, the tyre's torsional stiffness and d ing characteristics were calculated. The investigations were concerned with the low-frequency characteristics. It was found that there was a large torsional vibration associated with the tread pattern. Over the frequency range tested (10–50Hz), it was found that the d ing is more accurately represented as hysteretic and not viscous when lightly loaded. The effects of rotational speed, preload, and inflation pressure on the stiffness and d ing were also investigated. The d ing type for the tyre (hysteretic or viscous) was found to vary depending on the loading and excitation. Tyre properties were then included in a lumped-inertia, frequency-domain powertrain model and the steady-state response predicted. The results indicated that the viscous or hysteretic d ing assumption has significant effects on the predicted frequency response of the powertrain. The need for further studies investigating the d ing characteristics of automotive tyres in torsion is therefore recommended.
Narrow-Track Wheeled Agricultural Tractor Parameter Variation
Publisher: American Society of Agricultural and Biological Engineers (ASABE)
Date: 31-12-2013
Soil rock content influences the maximum seedling emergence depth of a dominant arid zone grass
Publisher: Springer Science and Business Media LLC
Date: 21-04-2020
Improvements to mechanical direct seeder design guided by the optimal sowing depth of soft spinifex (Triodia pungens)
Publisher: Australian Centre for Geomechanics, Perth
Date: 2019
The effect of piston friction on engine block dynamics
Publisher: SAGE Publications
Date: 06-2007
Abstract: When developing vibration models, so as to reduce model complexity, it is typically expected that good prediction accuracy can be achieved by ignoring the complication of friction. In this paper, the significance of friction between the piston and cylinder on engine block dynamics is shown through simulation in both the time and frequency domains. Simulations and experiments indicate that large differences exist between model predictions for the engine block moment if this friction is not accounted for. This is especially true at low crankshaft rotational speeds when dynamic inertia effects are small. Experiments on a motored single cylinder engine at different average rotational speeds confirm the theory and very good tie-up with predictions is obtained. It is expected that these findings will also have implications for the torsional vibration of the engine.
Operator protection in rollover events of articulated narrow track tractors
Publisher: Elsevier BV
Date: 09-2019
Torsional Receptances and Variable Inertia of a Two-Inertia Model of a Universal Joint
Publisher: Springer Netherlands
Date: 10-08-2012
Students’ responses to authentic assessment designed to develop commitment to performing at their best
Publisher: Informa UK Limited
Date: 15-12-2015
Factoring restoration practitioner perceptions into future design of mechanical direct seeders for native seeds
Publisher: Wiley
Date: 21-07-2019
DOI: 10.1111/REC.13001
A revised kineto-static model for Phase I tractor rollover
Publisher: Elsevier BV
Date: 09-2012
Energy Absorption in Actual Tractor Rollovers with Different Tire Configurations
Publisher: MDPI AG
Date: 17-06-2021
Abstract: In order to better understand the complexities of modern tractor rollover, this paper investigates the energy absorbed by a Roll-Over Protective Structure (ROPS) cab during controlled lateral rollover testing carried out on a modern narrow-track tractor with a silent-block suspended ROPS cab. To investigate how different tractor set-ups may influence ROPS and energy partitioning, tests were conducted with two different wheel configurations, wide (equivalent to normal ‘open field’ operation) and narrow (equivalent to ‘orchard/vineyard’ operation), and refer to both the width of the tires and the corresponding track. Dynamic load cells and displacement transducers located at the ROPS-ground impact points provided a direct measurement of the energy absorbed by the ROPS cab frame. A trilateration method was developed and mounted onboard to measure load cell trajectory with respect to the cab floor in real-time. The associated video record of each rollover event provided further information and opportunity to explain the acquired data. The narrow tire configuration consistently subjected the ROPS cab frame to more energy than the wide tire arrangement. To better evaluate the influence of the ROPS cab silent-blocks in lateral rollover, static and dynamic tests were performed. The results confirm that tires influence the energy partition significantly and that further understanding of silent-blocks’ dynamic performance is warranted.
Evaluation of the dynamic cone penetrometer to detect compaction in ripped soils
Publisher: Elsevier BV
Date: 2018
A historical review of the modulus concept and its relevance to mechanical engineering design today
Publisher: Elsevier BV
Date: 04-2012
The effect of piston friction on the torsional natural frequency of a reciprocating engine
Publisher: Elsevier BV
Date: 10-2007
Olive Pomace Requirements for Small Combustion Applications in Western Australia: Experimental and Modelling Analysis
Publisher: ETA-Florence Renewable Energies
Date: 2013
On farm automatic sheep breed classification using deep learning
Publisher: Elsevier BV
Date: 12-2019
Farmer-driven innovation: lessons from a case study of subterranean clover seed production
Publisher: Pluto Journals
Date: 2022
DOI: 10.13169/PROMETHEUS.37.4.0353
Abstract: Farmers are often overlooked and undervalued as sources of innovation, but can be powerful drivers of ingenuity and development. We evaluate historical developments in the Australian subterranean clover seed-production industry as a case study of farmer-driven innovation. Subterranean clover seed machinery patents (75% of which were patented by farmers) are analysed using conventional innovation frameworks, such as the theory of inventive problem solving (TRIZ), to extract lessons for supporting farmer-driven innovation. The small scale of this industry, compared with mainstream cereal-cropping industries and the isolation of farmers, provides analogous lessons for agriculture in developing countries. Economic drivers are important in enabling farmer innovation and the value proposition for developing new inventions must be clear to justify the time and expense. Farmers are different from firms and their on-farm knowledge and experience can form an essential part of innovation. Drivers of innovation also differ, with farmers less likely to attempt to commercialize inventions. Farmers can also be hesitant to share their inventions, instead holding them as trade secrets in competitive industries. Support and collaboration are needed from government and researchers to assist in commercialization or dissemination of useful innovations and to prevent knowledge from being confined to a localized farmer or region. Advances in agriculture require farmer input in research and development, but the benefits will be greater if farmers are enabled to be drivers of innovation.
Harvesting subterranean clover seed – current practices, technology and issues
Publisher: CSIRO Publishing
Date: 26-03-2021
DOI: 10.1071/CP20269
Abstract: Subterranean clover (Trifolium subterraneum L.) is Australia’s most widely sown annual pasture legume. Its widespread use as a pasture plant requires a well-functioning seed production industry, and Australia is the only significant producer of subterranean clover seed globally. However, the sustainability of this industry is under threat due to its reliance on ageing harvest equipment and the resultant environmental impacts. In order to evaluate seed harvesting practices, technology, and issues, we report on case studies, workshops, and a survey of seed producers across southern Australia. The Horwood Bagshaw Clover Harvester, designed in the 1950s, remains the most popular subterranean clover seed harvester. We discuss its use and modifications, and document several contemporary issues facing the seed production industry. Issues are primarily soil erosion and degradation the expensive, slow and labour-intensive harvest process and poor reliability and maintainability of harvesters that are now at least 30 years old. We conclude the root cause of these issues is the suction harvest technology utilised by the Horwood Bagshaw Clover Harvester. Analysis of the current harvest system is provided to support the development of new approaches to harvest subterranean clover seeds.
Engineering restoration for the future
Publisher: Elsevier BV
Date: 2021
The flow field in a centrifugal pump with a large tongue gap and back blades
Publisher: Springer Science and Business Media LLC
Date: 11-2014
Understanding and improving temporary road sign stability
Publisher: Australasian College of Road Safety
Date: 08-02-2023
Abstract: Temporary road signage is used throughout road networks to regulate traffic and provide warnings to road users. Wind and other factors induce frequent falling of temporary road signage and are a major road safety concern that needs to be addressed. The main aim of this paper was to gain an understanding of temporary road sign stability in the presence of passing road trains and investigate the possibility of stabilising temporary road signage through appropriate design modifications. Simulations and experimental trials were carried out to assess the stability of current temporary road signs used in the industry. This analysis used Ansys Fluent to simulate fluid dynamics in order to infer road sign stability. A field experimental trial was performed in Western Australia’s Pilbara Region using a modified temporary road sign developed based on the outcome of the Ansys simulation. The findings from the simulations showed that the current design is unstable and highly prone to wind induced failure. The simulations suggest that road train transit at 100 km/h is capable of inducing approximately 8 m/s wind velocity in the proximity of the sign, which is greater than that permissible for a rigid sign with no leg mobility. Field trials showed that the modified sign remained stable at 1.2 m from the edge line although it was still prone to falling over at closer distances.
Novel dynamic model for calculating the equivalent Young's modulus and loss factor of layered beams
Publisher: Elsevier BV
Date: 12-2020
A model and comparison of 4-wheel-drive fixed-chassis tractor rollover during Phase I
Publisher: Elsevier BV
Date: 10-2013
Selecting ROPS safety margins for wheeled agricultural tractors based on tractor mass
Publisher: Elsevier BV
Date: 03-2010
Flash flaming is a valid seed enhancement for a diverse range of species and seed morphologies
Publisher: International Seed Testing Association
Date: 31-12-2022
DOI: 10.15258/SST.2022.50.3.10
Abstract: Flash flaming has shown promise as a seed enhancement technology that improves the handling properties of bulky or irregularly shaped seed material, which in turn benefits logistical and ecological aspects of large-scale direct seeding. To date, only a small number of grass species, that possess similar morphological characteristics, have been tested. This paper describes the application of flash flaming to diaspores (i.e. the dispersal unit comprising the seed and any surrounding or attached tissues) of 19 erse dryland species from the Amaranthaceae, Asteraceae, Chenopodiaceae and Poaceae critical to ecological restoration in the mining intensive Pilbara region of Western Australia. Flash flaming parameters for each species were tested to identify and maximise volume and mass reduction, reduce particle cohesiveness and maximise flow through a mechanical seeding device, whilst maximising germination. Flaming of all species resulted in reductions in batch volume and mass, and improvements to flow characteristics. For 17 species, flaming either benefited or did not impact on germinability. For two species in the Amaranthaceae, flaming with the settings tested here resulted in a reduction in germinability however, flaming enabled the diaspores to pass through a mechanical seeding device enabling mechanical distribution which is critical if the species are to be used in large scale restoration.
Accuracy of Selection in Early Generations of Field Pea Breeding Increases by Exploiting the Information Contained in Correlated Traits
Publisher: MDPI AG
Date: 02-03-2023
Abstract: Accuracy of predicted breeding values (PBV) for low heritability traits may be increased in early generations by exploiting the information available in correlated traits. We compared the accuracy of PBV for 10 correlated traits with low to medium narrow-sense heritability (h2) in a genetically erse field pea (Pisum sativum L.) population after univariate or multivariate linear mixed model (MLMM) analysis with pedigree information. In the contra-season, we crossed and selfed S1 parent plants, and in the main season we evaluated spaced plants of S0 cross progeny and S2+ (S2 or higher) self progeny of parent plants for the 10 traits. Stem strength traits included stem buckling (SB) (h2 = 0.05), compressed stem thickness (CST) (h2 = 0.12), internode length (IL) (h2 = 0.61) and angle of the main stem above horizontal at first flower (EAngle) (h2 = 0.46). Significant genetic correlations of the additive effects occurred between SB and CST (0.61), IL and EAngle (−0.90) and IL and CST (−0.36). The average accuracy of PBVs in S0 progeny increased from 0.799 to 0.841 and in S2+ progeny increased from 0.835 to 0.875 in univariate vs MLMM, respectively. An optimized mating design was constructed with optimal contribution selection based on an index of PBV for the 10 traits, and predicted genetic gain in the next cycle ranged from 1.4% (SB), 5.0% (CST), 10.5% (EAngle) and −10.5% (IL), with low achieved parental coancestry of 0.12. MLMM improved the potential genetic gain in annual cycles of early generation selection in field pea by increasing the accuracy of PBV.
Using head mounted display virtual reality simulations in large engineering classes: Operating vs observing
Publisher: Australasian Society for Computers in Learning in Tertiary Education
Date: 19-03-2021
DOI: 10.14742/AJET.5487
Abstract: A barrier to using head mounted display (HMD) virtual reality (VR) in education is access to hardware for large classes. This paper compares students’ learning when engaging with an HMD VR simulation as the operator and as the observer, to evaluate whether benefits of HMD VR can be achieved without requiring all students to operate the equipment. Postgraduate engineering students (N = 117) completed a safety hazard identification exercise in a workshop. The performance of students who operated and observed was compared. Results showed that students performed similarly in the exercise that followed the simulation whether they operated HMD VR (n = 33) or observed (n = 84). The finding suggests that educators may be able to use HMD VR simulations in classes with a large enrolment, by reducing the need for investment and management of a large number of sets of HMD VR equipment. Implications for practice or policy: Engineering educators can use HMD VR simulations to teach students about safety in design. Engineering students are able to identify safety hazards in a HMD VR simulation effectively whether they are operating the equipment or observing another student in their group operating the VR equipment. One HMD VR set per student group is sufficient. HMD VR simulations can be used inclusively, even when some students are unable or unwilling to wear the headset.
A case study of seed-use technology development for Pilbara mine site rehabilitation
Publisher: Australian Centre for Geomechanics, Perth
Date: 2019
Compaction conditions greatly affect growth during early plant establishment
Publisher: Elsevier BV
Date: 09-2017
Modeling the Hysteresis Characteristics of Transformer Core under Various Excitation Level via On-Line Measurements
Publisher: MDPI AG
Date: 04-12-2018
DOI: 10.3390/ELECTRONICS7120390
Abstract: In this paper, the hysteresis characteristics of a transformer core are determined from limited on-line measured voltages and currents under certain excitations. A method for calculating the magnetization curve and hysteresis loops of the transformer core under various excitation is developed based on limited excitation conditions, and using the deep neural network, support vector regressor and the Wlodarski model. The coercivity and the litude of magnetic field strength of hysteresis loops can be captured with high accuracy based on this method. Then, a finite element model of the transformer core is constructed to predict the distributed magnetic flux density and the excitation current using the calculated hysteresis loops. The currents from various excitation voltages on two different transformer structures are also measured to compared with simulated currents. The outcome indicates that the overall hysteresis loops and magnetization curve of the transformer core may be useful for modeling the magnetic field and excitation current under any voltage excitation.
A chronology of subterranean clover burr detachment mechanics and implications for seed harvestability
Publisher: The Royal Society
Date: 11-2021
Abstract: Seed retention has not been evaluated for subterranean clover ( Trifolium subterraneum L.), because its geocarpic seed-bearing burrs are currently harvested by suction systems. Development of improved harvest methods requires knowledge of subterranean clover seed retention characteristics and their changes with plant development. This study evaluates burr attachment and peduncle tensile strength during burr maturity until plant senescence across the three subspecies: subterraneum (cv. Dalkeith), yanninicum (cv. Monti) and brachycalycinum (cv. Mawson). Peduncle tensile strength was greater than burr-to-peduncle attachment strength for each subspecies, with peak mean peduncle strength 30–130% greater than peak mean burr-to-peduncle attachment strength. Both strength measurements decreased significantly (greater than 50% for each subspecies) as the plant senesced, which was associated with reductions in burr moisture content, and burr and peduncle diameters. Microscopy indicated a ductile to brittle transition as peduncles senesced, reducing energy absorption and increasing the likelihood of failure at defects. These results are important for the commercial production of subterranean clover seed and suggest it may be possible to harvest seed before plant senescence with dig-invert machinery, similar to that used for peanut harvesting. However, this approach would require harvesting prior to maximum seed development and the implications for seed viability and yield need to be further evaluated.
Static stability analysis of non-slewing articulated mobile cranes
Publisher: Informa UK Limited
Date: 2014
Measurement of Pressure Fluctuations inside a Model Thrust Bearing Using PVDF Sensors
Publisher: MDPI AG
Date: 16-04-2017
DOI: 10.3390/S17040878
Flash flaming effectively removes appendages and improves the seed coating potential of grass florets
Publisher: Wiley
Date: 20-05-2016
DOI: 10.1111/REC.12386
A Mobility Assignment with Industry Relevance
Publisher: Springer Netherlands
Date: 10-08-2012
Correlation of centrifugal pump vibration to unsteady flow under variable motor speed
Publisher: EDP Sciences
Date: 2014
DOI: 10.1051/MECA/2014051
Contact Force Measurement in an Operational Thrust Bearing using PVDF Film at the Blade and Pad Passing Frequencies
Publisher: MDPI AG
Date: 15-11-2018
DOI: 10.3390/S18113956
Abstract: A major contributor to longitudinal vibration in marine propulsion systems is propeller induced excitation. This constitutes a key source of underwater acoustical radiation through excitation of the hull. Understanding this hydrodynamic force at the interface of the thrust bearing is important in order to develop an accurate vibrational model of the propulsion system and in determining potential control mechanisms. In order to investigate the thrust force during operation of a propulsion system, Polyvinylidene Fluoride (PVDF) was embedded into the stationery collar inside a custom thrust bearing in a scaled model of a typical propulsion system. The number of blades of the propeller and its rotational speed were altered to obtain an understanding of the characteristic vibrations of the shaft propulsion system. The rig comprised of the propeller, shaft, journal bearings and a thrust bearing. A two and three blade propeller and a four, five and six pad bearing were tested. A strain gauge and accelerometer were used to infer the propeller force and enable comparison with the PVDF signals. As a result of the asymmetrical flow around the propeller, the blade passing frequencies (BPF) are clearly observed. This frequency contribution was present at all speeds tested. The PVDF signal also showed significant pad passing frequency (PPF) and BPF and modulation of both.
A Numerical Study of the Unsteady Flow Field and Tonal Hydrodynamic Sound of a Centrifugal Pump
Publisher: American Society of Mechanical Engineers
Date: 13-11-2015
Abstract: In this paper, the 3-D unsteady turbulent flow inside a centrifugal pump is investigated by computational fluid dynamics (CFD) in ANSYS CFX, using Detached Eddy Simulation (DES) as the turbulence approach. The pump has a single end-suction and a single volute discharge. The impeller is semi-open (unshrouded with baseplate) and has five backswept blades and pump-out back blades. The CFD model of the pump consists of the inlet, the impeller, and the volute. A sliding mesh technique has been applied to the interfaces in order to allow unsteady interactions between the rotating impeller and the stationary parts. These unsteady interactions generate pressure fluctuations over the volute casing and blade surfaces that are hydroacoustic dipoles according to Lighthill’s acoustic analogy theory. The pressure fluctuation spectra at the volute tongue show that pressure fluctuations are generated mainly by the discrete components related to the impeller rotation at low frequencies, especially the blade-passing frequency (BPF) component. This component is approximately 1% of the reference dynamic pressure 0.5ρν22 where ν2 is the circumferential velocity at the impeller outlet. The discrete components with frequency larger than 4 times BPF are no longer obvious in the spectra. Compared to the experimental results, the CFD simulation predicts much lower litudes for the broad band pressure fluctuations. This is reasonable, because DES combines a classical Reynolds averaged Navier Stokes (RANS) simulation with elements of Large Eddy Simulation (LES), and both RANS and LES use average methods which filter out the high frequency fluctuations. Nevertheless, CFD is capable of accurately predict the BPF component. The pressure fluctuations on the casing and blade surfaces are extracted and modelled as the stationary and rotary dipoles, respectively, according to the Ffowcs Williams and Hawkings (FW-H) equation of the acoustic analogy theory. After Fast Fourier Transform, the spectra of the pressure fluctuations are obtained, and are used to predict the tonal hydrodynamic sound radiation at BPF and its low order harmonics. The sound radiation of casing surface dipoles is calculated by extracting the tonal components, and performing a surface integration with the fundamental solution to Helmholtz equation as the kernel. A frequency domain formulation of the FW-H equation with the moving surface dipole is employed to predict the tonal blade noise. The results from these acoustical simulations show that the sound power generated by the casing surface dipole is three orders of magnitude higher than that of the blade surface dipole, and the main hydroacoustic sources are located at the volute tongue.
Monitoring single-stage double-suction pump efficiency using vibration indicators
Publisher: SAGE Publications
Date: 20-09-2013
Abstract: Efficiency tests were conducted on two single-stage double-suction split-case pumps in a clean water distribution facility. Efficiency was monitored via two techniques, one established and the other proposed in this study. Measurements of the former were taken via the standard technique using a Yatesmeter that required time to calibrate and that probes be inserted into the clean water flow the latter method was non-intrusive, being based solely on accelerometer measurements at key locations on the volute/split casing. Both techniques required some post-processing of data. Through comparison of the techniques, it is shown that for the pumps that were analysed it is possible to extract indicators within the vibration signatures that permit good correlation with efficiency data. In both cases only a few recorded measurement points were possible and the vibration indicator-based curve fitting technique was able to locate the best efficiency point more accurately than using the curve fitted to the Yatesmeter measured data. This short communication reports on the initial tests which are showing promising results.
Using VR to teach safety in design: what and how do engineering students learn?
Publisher: Informa UK Limited
Date: 03-02-2023
A century of subclover: Lessons for sustainable intensification from a historical review of innovations in subterranean clover seed production
Publisher: Elsevier
Date: 2022
Available energy during the rollover of narrow-track wheeled agricultural tractors
Publisher: Elsevier BV
Date: 11-2009
Tillage based, site-specific weed control for conservation cropping systems
Publisher: Cambridge University Press (CUP)
Date: 19-03-2020
DOI: 10.1017/WET.2020.34
Abstract: Australian conservation cropping systems are practiced on very large farms (approximately 3,000 ha) where herbicides are relied on for effective and timely weed control. In many fields, though, there are low weed densities (e.g., .0 plant 10 m −2 ) and whole-field herbicide treatments are wasteful. For fallow weed control, commercially available weed detection systems provide the opportunity for site-specific herbicide treatments, removing the need for whole-field treatment of fallow fields with low weed densities. Concern about the sustainability of herbicide-reliant weed management systems remain and there has not been interest in the use of weed detection systems for alternative weed control technologies, such as targeted tillage. In this paper, we discuss the use of a targeted tillage technique for site-specific weed control in large-scale crop production systems. Three small-scale prototypes were used for engineering and weed control efficacy testing across a range of species and growth stages. With confidence established in the design approach and a demonstrated 100% weed-control potential, a 6-m wide pre-commercial prototype, the “Weed Chipper,” was built incorporating commercially available weed-detection cameras for practical field-scale evaluation. This testing confirmed very high (90%) weed control efficacies and associated low levels (1.8%) of soil disturbance where the weed density was fewer than 1.0 plant 10 m −2 in a commercial fallow. These data established the suitability of this mechanical approach to weed control for conservation cropping systems. The development of targeted tillage for fallow weed control represents the introduction of site-specific, nonchemical weed control for conservation cropping systems.
A general articulation angle stability model for non-slewing articulated mobile cranes on slopes
Publisher: Informa UK Limited
Date: 2014
Variable inertia effects of an engine including piston friction and a crank or gudgeon pin offset
Publisher: SAGE Publications
Date: 03-2008
Abstract: In order to obtain greater accuracy in simulation, more sophisticated models are often required. When it comes to the torsional vibration of reciprocating mechanisms the effect of inertia variation is very important. It has been shown that the inclusion of this variation increases model accuracy for both single-cylinder and multi-cylinder engine torsional vibration predictions. Recent work by the present authors has revealed that piston-to-cylinder friction may modify an engine's ‘apparent’ inertia function. Kinematic analysis also shows that the piston side force and the dynamic piston-to-cylinder friction are interdependent. This has implications for engine vibration modelling. Most modern engines employ a gudgeon pin offset, and there is a growing interest in pursuing large crank offsets hence, the effect of these on inertia variation is also of interest. This paper presents the derivation of the inertia function for a single engine mechanism, including both piston-to-cylinder friction and crank or gudgeon pin offset, and investigates the effect of each through predictions. The effect of crank offset on the variable inertia function is also verified by experiment.
Reducing the Integrated Harrington Seed Destructor Power Requirements through Chaff Fraction Optimization
Publisher: American Society of Agricultural and Biological Engineers (ASABE)
Date: 2017
DOI: 10.13031/AEA.12154
Abstract: Mechanical weed seed destruction during harvest is an effective method of reducing viable weed seed inputs to the seedbank. The commercialized Integrated Harrington Seed Destructor (iHSD) was developed for destroying weed seeds contained in the chaff residue exiting the harvester. Considered state-of-the-art in harvest weed seed control (HWSC), weed seed destruction is achieved without crop residue loss (burning or removal) and therefore, the iHSD is well suited to use in conservation cropping systems. However, as the iHSD is powered directly by the harvester its power draw impacts harvester performance. The objectives of this study were to determine the iHSD mill power requirements for effective weed seed destruction and to identify opportunities for decreasing these requirements. Using a torque-arm arrangement, the power requirements of an iHSD mill test rig powered by a PTO drive were measured. Wheat chaff containing a known amount of annual ryegrass () seed was passed through decreasing aperture sized sieves to obtain chaff size and seed distributions. The standard power demand to process chaff was ~54 kW, restricting the use of this system to large capacity harvesters. It was found that annual ryegrass seeds were concentrated in the chaff fraction passing through a 3 mm sieve. The power demand for processing this refined fraction was reduced by approximately a third to ~36kW. Efficient mechanical means to refine the chaff fraction to focus on the weed seed portion should be investigated. Keywords: Agricultural engineering, Conservation cropping, Efficiency, Harvest weed seed control, Herbicide resistance, Mechanical weed seed destruction,
Precision metering of Santalum spicatum (Australian Sandalwood) seeds
Publisher: Elsevier BV
Date: 06-2013
Related Organisations
Related Funding Activities
Industrial Transformation Training Centres - Grant ID: IC210100008
Start Date: 08-2022
End Date: 08-2026
Amount: $4,282,859.00
Funder: Australian Research Council
View Funded Activity