TY - RPRT A1 - Jahr, Andreas A1 - Batos, Andrej A1 - Happel, Holger T1 - Modellierung eines Strohhalmes in einem Mehrkörpersimulationsprogramm T1 - Modeling of a Wheat Straw by Means of a Multi Body Simulation Program N2 - 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. N2 - The present paper investigates into the technique of modeling a wheat straw using the multi body simulation program SIMMECHANICS being an add-on of the simulation and calculation program MATLAB(R) or SIMULINK(R) respectively. Modeling of the straw aims at simulating the cutting process taking place inside a combined harvester. Step one identifies meaningful data concerning the characteristics of the straw with respect to the cutting process, in particular blade mass, angle resilience- and angle damping constant. Step two shows how modelling of the straw is performed using SIMMECHANICS. The final chapter compares the simulation model with the behaviour of a typical straw as found in nature. KW - Simulation KW - Erntetechnik KW - Häcksler KW - Messung KW - Land- und Agrartechnik KW - simulation KW - harvest KW - crop chopper KW - measurement KW - agricultural technology KW - FHD Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-3624 CY - Düsseldorf ER - TY - RPRT A1 - Bhaiya, Madhur A1 - Jahr, Andreas A1 - Happel, Holger T1 - Harvesting-Combine-Flow Simulation Technique N2 - 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. KW - Häckseln KW - Ernte KW - Stroh KW - Partikelstrom KW - CFD KW - chaff KW - harvesting KW - Particle flow KW - simulation KW - FHD Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-4239 CY - Düsseldorf ER -