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Rotary mowers are ofen used for forage harvesting in agriculture, as this technology can achieve a high throughput. These knives are therefore exposed to high levels of wear and tear, and will also be ofen changed because of loss of material by bad cutting quality. That
is why it is interesting to save costs during manufacturing in spite of a correspondingly long service life. This research records the current manufacturing quality of the mower blades and examines how they behave in comparison. Based on the obtained results, further decisions on the methods, procedures and ways of extending the life of the disc mower blades should be proposed. For the investigations, a test bench based on a wear pot was used. The wear that occurs on the blade is determined using several parameters and compared accordingly. The parameters of the test setup determined as a result of the test can be used for further studies of wear resistance.
Synthesis and Analysis of a Novel Linkage Mechanism with the Helical Motion of the End-Effector
(2020)
CFX 11.0 is a Computational Fluid Dynamics (CFD) program for simulating the behavior of systems involving fluid flow, heat transfer, and other related physical processes. It works by solving the equations of fluid flow (in a special form) over a region of interest, with specified (known) conditions on the boundary of that region. This tool is used here to analyse the straw cutter which is used to comminute the straw which is left standing in the field after stripper header has stripped the grains from the crops. Stripper Header is a new technique different to conventional harvester machines and it is still under development and testing. It works on the principle in which grains are first stripped off from the head of the standing crop which helps in much reduced intake freeing up the separation systems to handle a larger volume of grains. But with this, the new problem of the disposal of the long, uncut straw left after stripping of grains arose. So a straw cutter is used after the stripper header stage in this Combine Harvester, where the rotor is equipped with pressed steel blades and rotates towards the crop, i.e., it cuts and lifts the straw over the top. This technique is environment friendly because previously farmers would have to burn the long, uncut straw standing in the fields while in this case mulched straw can be used for min-till systems. This rotor based straw cutting machine is analysed here which helps us in increasing power efficiency and comminution rate and quality of cut straw particles. Here fluid flow simulation has been preferred over particle simulation: - CFX 10.0 tool is not very effective for particle simulation techniques and computation time is increased considerably. - It’s very hard to realize particle simulation in CFX 10.0 because we have to define size and properties of each particle and besides this wall conditions would have to be defined differently for every boundary. - Besides this, it’s hard to realize cutting effect with straw particles in CFX 10.0 which otherwise would be comminuted in real life conditions. - The results obtained from fluid simulation are validated using experimental results and found to be nearly the same which clearly contradicts any need of performing particle simulation.
Im Rahmen dieser Ausarbeitung wird gezeigt, wie ein Weizenstrohhalm in dem Mehrkörpersimulationsprogramm SIMMECHANICS, das ein Zusatztool des Simulations- und Berechnungsprogramms MATLAB(R) bzw. SIMULINK(R) ist, modelliert werden kann. Die Modellierung erfolgt mit dem Ziel, den im Mähdrescherhäcksler stattfindenden Schnittprozess zu simulieren. Dazu werden zuerst die für einen Schnitt relevanten Eigenschaften des Weizenstrohhalmes ermittelt. Dies sind insbesondere die Halmmasse sowie die Winkelfeder- und Winkeldämpfungskonstante. Anschließend wird die Modellierung des Halmes in dem genannten Mehrkörpersimulationsprogramm gezeigt. Abschließend erfolgt ein Vergleich des erstellten Simulationsmodells mit dem realen Strohhalm.