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Modeling soil-moldboard plough interaction using FEM and CFD techniques | |
Author | Pipit Kunlawanit |
Call Number | AIT Thesis no.AE-09-06 |
Subject(s) | Tillage--Simulation methods |
Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Agricultural Systems & Engineering, School of Environment, Resources and Development |
Publisher | Asian Institute of Technology |
Series Statement | Thesis ; no. AE-09-06 |
Abstract | The optimization of the factors associated with soil-moldboard plough interaction is important for minimizing the energy need for tillage. There is no precise methodology for designing a moldboard plough (MP), particularly the oblique surface, shape and proportional sizing for optimum performance. Although, many mathematical models have been developed, the process still found to be complicated. In this study, emphasis was given to develop a methodology for utilizing computer assisted analyses, Solid work models, FEM/CFD methods in ANSYS 11 software, to develop computer generated 3-D geometrical models of MP having optimum performance. Simulation programs were developed and validated to obtain soil flow patterns under controlled condition, which produces minimum resistance and remains within laminar flow limits. The study had three phases; firstly to develop computer based, combined Solid work and FEM/CFD 3-D moldboard plough models in order to simulate plough forces under different operating conditions, secondly to design and fabricate MP models with optimized geometry, and finally, to validate developed models using soil-bin experiments. Initial data such as soil, plough and operating parameters were fed to the software to create models. Experiments were conducted in small soil-bin to validate the effect of share lift angle, and radius of curvature and the working depth on forces on MP. Selected plough design parameters after the small soil-bin experiments and FEM simulation were; share lift angle of 25°, and radius of curvature of 180 mm, which were used to fabricate the new MP model for validation in large soil-bin. The large soil-bin was used to validate the effect of traveling speed in the range 0.1 - 0.3 mis, operation depth at 15 cm, compaction at 350 kPa, and moisture content at 27%. Three dimensional contour maps indicating areas having high or low forces, were created for varying experimental conditions; soil moisture, soil compaction, viscosity, plough radius of curvature, share angle, operating depth and speed. Soil flow patterns were visualized to fmd the critical surface features of the MP and to optimize the design. The comparison of experimental and FEM/CFD simulated results on tool forces draft, lift and side, showed very good agreement in all directions. During the model validation step, through statistical tests, good correlations were observed for FEM/CFD and experimental results under quasi-static and dynamic conditions, so that FEM/CFD models can be used to simulate plough-soil interaction accurately and can be used for design optimizations. |
Year | 2009 |
Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AE-09-06 |
Type | Thesis |
School | School of Environment, Resources, and Development (SERD) |
Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
Academic Program/FoS | Agricultural and Food Engineering (AE) |
Chairperson(s) | Jayasuriya, Hemantha P. |
Examination Committee(s) | Salokhe, Vilas M.;Soni, Peeyush;Roongruang Kalsirisilp |
Scholarship Donor(s) | Asian Institute of Technology Fellowship;RTG Fellowship |
Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2009 |