Simulation key to BMW's Valvetronic concept

Enhanced multibody analysis tools supported development of the new engine technology.

BMW's Valvetronic engine is the first series production engine to feature mechanical infinitely variable valve lift, improving fuel economy by eliminating the pressure loss of the throttle valve. The engine has an advantage over gasoline direct-injection engines since it offers equivalent fuel economy but is not limited by fuel quality. Design of the all-new valvetrain was critical because of the major impact it has on power output, fuel economy, and NVH.

Engineers from BMW used multibody simulation software from LMS International to evaluate critical mechanical characteristics well before physical prototypes were built. In the early design stage, kinematic and dynamic models of the single valvetrain were used for component layout and optimization. Later, a full-engine model was developed to evaluate effects that vary from cylinder to cylinder, which were especially important in this design because the valvetrain is used to control engine speed. “The high quality of the Valvetronic engine design would not have been achieved without using multibody simulation,” said Michael Allgeier, Mechanical Systems Engineer at BMW.