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Engine manufacturers are increasingly concerned about oil consumption due to its implications for operating costs, emissions, and durability in both diesel and natural gas-powered engines. As future engines aim for low or near-zero emissions while utilizing low/zero carbon fuels, lubricant oil consumption will play a critical role in achieving decarbonization and emissions targets. Hydrogen-fuelled engines, in particular, will be more vulnerable to oil droplet and oil ash-based pre-ignition. Traditionally, the influence of key design parameters on oil consumption has been determined during the validation phase of an engine development program, which entails extensive testbed hours and time-consuming hardware iterations. As a result, development programs may be unable to optimize oil consumption due to cost and time constraints.

In this paper, a mathematical model for simulating the 3D dynamic response of a valve spring is described. The 3D model employs a ‘geometrically exact’ 3D beam connected between each mass of the discretised mass-elastic system. Shear deformations within the beam are also considered, which makes it a Timoshenko type finite element. Results from the 3D model are compared with results from a more conventional 1D model. To validate the results further, some results are compared with real test data that was gathered during a technical consulting project. In this project, a prototype valvetrain that was originally giving acceptable durability began to wear the spring seats when a new batch of springs were procured and tested. 1D and 3D simulation results were used to help understand the cause of the failure and to make recommendations to resolve the issue. Results showed that the 3D model was able to predict the spring seat loads with greater precision than the 1D spring could.

Most major regional automotive markets have stringent legislative targets for vehicle greenhouse gas emissions or fuel economy enforced by fiscal penalties. Large improvements in vehicle efficiency on mandated test cycles have already taken place in some markets through the widespread adoption of technologies such as downsizing or dieselization. There is now increased focus on approaches which give smaller but significant incremental efficiency benefits such as reducing parasitic losses due to engine friction. Fuel economy improvements which achieve this through the development of advanced engine lubricants are very attractive to vehicle manufacturers due to their favorable cost-benefit ratio. For an engine with components which operate predominantly in the hydrodynamic lubrication regime, the most significant lubricant parameter which can be changed to improve the tribological performance of the system is the lubricant viscosity.