The information below was gathered from the 2018 Simcenter Conference - Americas that took place October 15-17 in Detroit, Michigan.
Author: Rohit Saha, Senior Technical Specialist-Machine Simulation
To optimize powertrain or other component design for better fuel economy and performance in off-highway applications, it is critical to model the machine with system level tool for a complete representation. System-level model will, hopefully, capture the energy demand from each main machine components, their transfer channels, and connections between machine performance and powertrain output. This paper focuses on a couple of examples by using this approach. The first example is to study the various components and their design factors on a wheel loader. With a system level model including engine, drive-line, hydraulics, working mechanism, cooling system, and operator, the author explored various engine fuel maps/torque curves, transmission torque converters, rear axle ratios, and hydraulic pumps. More interestingly, 3-D CFD tool is introduced to calibrate the cooling system and generated accurate flow rates from this 1-D Amesim system-level model to gain fuel economy improvement. The second example is to optimize & integrate engine and pump controls of an excavator in a machine level model. This model consists of engine model with engine controls, hydraulics model with pump controls, working mechanism, and fan. In this study, optimized governor controls of the engine are shown to help improve machine transient performance when the engine is subjected to sudden loading. Selection of fan geometry is based in whole machine level 3D CFD. Both simulation and test confirm new fan will consume lower power and produce lower noise. These two examples highlight the power of system-level modeling for better machine integration.