Possibilities for Reducing Combustion Engine Fuel Consumption and Gas Emissions

Puškár

2022

MATEC Web Conf.

Self Cite

Modern-day approaches to reducing the emissions of combustion engines lead to unconventional strategies which include downspeeding, downsizing, cylinder deactivation. A common characteristic of these strategies is a shift in torque excitation components of the combustion engine. This excitation shift results in an increase in vibrations of the drivetrain and the risks associated with it. The presented article aims to investigate the elementary characteristics of the pure cubic nonlinear system and to identify the potential for its use in mechanical systems.

Section: Introductionmentioning

confidence: 99%

The potential for use of cubic nonlinear systems in internal combustion engine drivetrains

Puškár

2022

MATEC Web Conf.

Self Cite

“…The reduction of vibration levels is therefore a very worthwhile subject. Engineering research in this area is focused on reducing vibrations below the levels imposed by regulations, which improves interactions in the man-machine-environment system [2]. Although it is presently not possible to entirely eliminate vibrations, the aim is to reduce them to an acceptable level [3,4].…”

Section: Introductionmentioning

confidence: 99%

Bulletin of the Polish Academy of Sciences: Technical Sciences

Homišin

2021

Several approaches are typically used to reduce torsional vibrations in mechanical systems with piston-driven engines [14,15]. Various types of f lexible couplings and dual-mass f lywheels are widely implemented [16][17]. It has been demonstrated that pneumatic tuners with adjustable torsional stiffness can be used to achieve active tuning of torsional vibrations [19][20][21][22][23]. Certain research ventures have focused on the application of nonlinear energy sink (NES) [24] and targeted energy transfer (TET) [25] with the goal of designing a device with quasi-zero torsional stiffness [26]. These research avenues require new approaches to solving analytical models. It is common practice in engineering that complicated systems are simplified -e.g. nonlinear systems are often linearised around an operating point. While in some cases linearisation is adequate as demonstrated in [27][28][29], there are applications that require nonlinear models because linearisation either does not provide sufficient accuracy, or is not possible at all [30].The first step in extending the linear model is the addition of a cubic term. Such a system, governed by the Duffing equation, has been the subject of numerous analyses [31]. Extensive mathematical tools have been developed to model the system, whether the nonlinearity is weak or strong.In this presented work, we decided to focus on a different type of a nonlinear system. Systems with power-law restoring force have not been extensively studied, in spite of the fact that they may occur naturally in many engineering problems. The source of nonlinearity can be contact law, such as Hertzian potential, for which restoring force f varies with displacement q as f ∝ q 1.5 . Further examples include systems without pre-tension or systems tuned to zero stiffness around the operating point. If the force-carrying medium is gas, such as in the pneumatic tuners [18], the restoring force is also inherently nonlinear with power-law dependence.

The requirements for the design of dual-mass flywheels

IOP Conf. Ser.: Mater. Sci. Eng.

Jakubovičová

Sága

2020

In the modern powertrains with new low emission combustion engines, the effort to reduce emissions and weight of the entire system increase the efficiency of vehicle drives but also make the drive much more sensitive to vibration. The new design concepts of dual-mass flywheels offer more options for eliminating vibration in vehicle drive systems. Every design of the dual-mass flywheel must ensure that it has the appropriate characteristics. A suitable characteristic then creates a prerequisite for application in a drive in which the resonance area can be moved to very low operating speed.