Search Results

This work describes the development and use of the Hardware-in-the-Loop (HIL) technique to evaluate the dynamic behavior of a torsional vibration rubber damper (TVD) used in a spark ignition internal combustion engine. The TVD was adapted to a test bench designed for this research and the HIL technique was applied considering the simulated dynamic response of the crankshaft. The results of the torsional vibration amplitudes are compared with measured values in a steady-state well identified condition, to experimentally validate the proposed mathematical model and the possibility to use the HIL technique to evaluate dampers and crankshaft behavior in realistic long term tests, where the rubber degradation also affects the dynamic response of the system. Finally, it was concluded that simulated and measured signals presented a good correlation in some engine operational conditions, reaching the objectives of this study.

This paper presents the comparison of two different approaches for crankcase structural analysis. The first approach is a conventional quasi-static simulation, which will not be detailed in this work and the second approach involves determining the dynamic loading generated by the crankshaft torsional, flexural and axial vibrations on the crankcase. The accuracy of this approach consists in the development of a robust mathematical model that can couple the dynamic characteristics of the crankshaft and the crankcase, representing realistically the interaction between both components. The methodology to evaluate these dynamic responses is referred to as hybrid simulation, which consists of the solution of the dynamics of an E-MBS (Elastic Multi Body System) coupled with consecutive FEA (Finite Element Analysis).

Withdrawal of heat from internal combustion engines is a major concern in today's automotive industry, mainly due to material constraints and components durability. In this sense, a numerical study was conducted to analyze the water flow inside MWM INTERNATIONAL's high-speed diesel engine, in order to determine possible cavitation regions, which can reduce the heat transfer efficiency. The analysis is carried out with the help of computational fluid dynamics (CFD) commercial software FLUENT, from ANSYS Inc. The model was built as steady-state, turbulent, single phase flow. Heat transfer from the solid water jacket to the fluid zone was also considered. For this reason, the cavitation regions were identified through vapor pressure.

This Paper presents a study of weight reduction in an exhaust manifold of a four cylinders, 3.0 liters Diesel engine. The mass of the entire engine shall be reduced from the current 290kg to 260kg and many components will be redesigned focused on this target. Basically, the wall thickness and flanges of the exhaust manifold will be redesigned and reduced to a value which shall guaranties the component durability. The calculations will be made determining the life cycle of the proposed exhaust manifold, checking if no structural problems can occur. The shape and size of the ducts remain unchanged for performance purposes and no material changes will be considered for the new component.

This work presents the results and methodology of a dynamic durability analysis considering the interaction between crankcase and crankshaft. The approach is based on a robust mathematical model that couples the dynamic characteristics of the crankshaft and crankcase, representing the actual interaction between both components. Dynamic loadings generated by the crankshaft are transferred to the crankcase through flexible 3D hydrodynamic bearings. This methodology is referred to as hybrid simulation, which consists in the solution of the dynamics of an Elastic Multi-Body System (E-MBS) coupled with the Finite Element Methodology (FEM). For this study, it was considered an in-line 6-cylinder diesel engine used in off-road applications. The crankcase design must withstand higher loads due to new calibration targets stipulated for PROCONVE (MAR-I) emission regulations.

Withdrawal of heat from internal combustion engines is a major concern in today's automotive industry, mainly due to material constraints and components durability. A well-designed cooling system may increase engine's reliability. In the light of this, a numerical study has been conducted to analyze the water flow inside MWM INTERNATIONAL's high-speed diesel engine. The study has been done in order to determine possible cavitation and boiling regions, which can reduce the heat transfer efficiency. The analysis was carried out with the help of computational fluid dynamics (CFD) commercial software ANSYS FLUENT®. The flow was considered to be steady-state, turbulent, with heat transfer and the fluid was treated as a single phase. For this reason, the possible cavitation and boiling regions are identified through vapor pressure and boiling temperature, respectively.