Abstract: A piston for an internal combustion engine is disclosed. The piston includes an upper surface configured to at least partly face a cylinder head of the internal combustion engine. The upper surface includes a combustion bowl surface, and a squish face having an internal edge disposed a first distance from the longitudinal axis along a radial direction. The combustion bowl surface includes a planar surface extending radially outward from the longitudinal axis of the piston, a first concave surface disposed outside the planar surface in the radial direction, the first concave surface having a first radius of curvature, and a second concave surface disposed outside the first concave surface in the radial direction, the second concave surface having a second radius of curvature, the second radius of curvature being smaller than the first radius of curvature.

Abstract: A piston for an internal combustion engine is disclosed. The piston includes an upper surface configured to at least partly face a cylinder head of the internal combustion engine. The upper surface includes a combustion bowl surface, and a squish face having an internal edge disposed a first distance from the longitudinal axis along a radial direction. The combustion bowl surface includes a planar surface extending radially outward from the longitudinal axis of the piston, a first concave surface disposed outside the planar surface in the radial direction, the first concave surface having a first radius of curvature, and a second concave surface disposed outside the first concave surface in the radial direction, the second concave surface having a second radius of curvature, the second radius of curvature being smaller than the first radius of curvature.

Abstract: An engine emissions control system is provided. The system may include an exhaust producing engine and an exhaust system through which the exhaust produced by the engine may flow. The system may also include a NOx sensor configured to take a NOx measurement of the amount of NOx in the exhaust produced by the engine. The system may further include a charge density sensing system configured to measure the charge density of a combustion mixture of the engine. In addition, the system may include a controller configured to receive information related to the measurement of the amount of NOx. The controller may be further configured to control a charge density of the combustion mixture with which the engine operates based on the NOx measurement and the charge density measured by the charge density sensing system.