An igniter having at least two electrodes spaced from each other by an insulating member having a substantially continuous surface along a path between the electrodes. The electrodes extend substantially parallel to each other for a distance both above and below said surface. The insulating member has a channel (recess) for receiving at least a portion of a length of at least one of said electrodes below and to said surface of the insulating member. The surface of the insulating member may preferably be augmented with a conductivity enhancing agent. The insulating member and electrodes are configured so that an electric field between the electrodes at said surface does not have abrupt field intensity changes, whereby when a potential is applied to the electrodes sufficient to cause breakdown to occur between the electrodes, discharge occurs at said surface of the insulating member to define a plasma initiation region.

Lean-burn engines are important due to their ability to reduce emissions, increase fuel efficiency, and mitigate engine knock. Embodiments of a spark plug with a nanostructured electrode extend the lean flammability limit of natural gas. A nano-/micro-morphology modification is applied on a surface of the spark plug electrode to increase its surface roughness. Measurements indicate that the lean flammability limit of spark-ignited methane can be lowered by modulating the surface roughness of the spark plug electrode with nanostructures.

Lean-burn engines are important due to their ability to reduce emissions, increase fuel efficiency, and mitigate engine knock. Embodiments of a spark plug with a nanostructured electrode extend the lean flammability limit of natural gas. A nano-/micro-morphology modification is applied on a surface of the spark plug electrode to increase its surface roughness. Measurements indicate that the lean flammability limit of spark-ignited methane can be lowered by modulating the surface roughness of the spark plug electrode with nanostructures.

An object herein is to provide, with respect to a spark ignition-type internal combustion engine in which the pressure of the air-fuel mixture in the combustion chamber becomes high, an ignition device which can suppress occurrence of a creeping discharge and thus contributes to highly efficient operation of the internal combustion engine. The ignition device according to this application includes: an ignition plug having a high-voltage side electrode and a ground side electrode; a high voltage generation device that applies a voltage to the high-voltage side electrode of the ignition plug; and an extension device that extends a dielectric breakdown-reaching time period that is a time period from when the voltage is applied to the high-voltage side electrode of the ignition plug, to when a voltage between the high-voltage side electrode and the ground side electrode of the ignition plug reaches a dielectric breakdown voltage.

An object herein is to provide, with respect to a spark ignition-type internal combustion engine in which the pressure of the air-fuel mixture in the combustion chamber becomes high, an ignition device which can suppress occurrence of a creeping discharge and thus contributes to highly efficient operation of the internal combustion engine. The ignition device according to this application includes: an ignition plug having a high-voltage side electrode and a ground side electrode; a high voltage generation device that applies a voltage to the high-voltage side electrode of the ignition plug; and an extension device that extends a dielectric breakdown-reaching time period that is a time period from when the voltage is applied to the high-voltage side electrode of the ignition plug, to when a voltage between the high-voltage side electrode and the ground side electrode of the ignition plug reaches a dielectric breakdown voltage.

A passive prechamber spark plug for use in a combustion chamber of a vehicle engine includes an upper prechamber having an upper opening where the upper prechamber is connectable to the combustion chamber via the upper opening. An air ignition spark is formable via an upper air spark gap. A central electrode is disposed in an upper region of the upper prechamber where a base of the upper prechamber opposite the upper region is an insulator. An electrically conductive element or a slot is guided by the insulator continuously from the upper prechamber into a lower region under the base and the lower region is either a lower prechamber or is arrangeable directly in the combustion chamber. An earth electrode is disposed in the lower region such that a lower air-surface gap spark gap is formed between the earth electrode and the electrically conductive element or the slot.

A passive prechamber spark plug for use in a combustion chamber of a vehicle engine includes an upper prechamber having an upper opening where the upper prechamber is connectable to the combustion chamber via the upper opening. An air ignition spark is formable via an upper air spark gap. A central electrode is disposed in an upper region of the upper prechamber where a base of the upper prechamber opposite the upper region is an insulator. An electrically conductive element or a slot is guided by the insulator continuously from the upper prechamber into a lower region under the base and the lower region is either a lower prechamber or is arrangeable directly in the combustion chamber. An earth electrode is disposed in the lower region such that a lower air-surface gap spark gap is formed between the earth electrode and the electrically conductive element or the slot.

The invention relates to a semiconductor body revolving around a main axis (A) for a spark plug of a turbine engine, the semiconductor body comprising a baseplate and an upper portion extending from the baseplate along the main axis, the baseplate comprising a bottom surface substantially defined in a plane perpendicular to the main axis and a first conical surface intended to cooperate by form-fitting at least partially with a contact surface of an outer electrode of the spark plug. According to the invention, the upper portion comprises an interface located opposite the bottom surface along the main axis (A) and featuring a profile that is at least partially corrugated.

A combustor for a gas turbine system includes a combustor casing having an interior-establishing wall, and a chamber extending to the interior-establishing wall. In addition, the combustor includes an igniter assembly disposed within the chamber such that a tip of the igniter assembly is positioned radially outwardly from the interior-establishing wall. The igniter assembly includes a first electrode, a second electrode, and an insulator. In addition, the first electrode, the second electrode, and the insulator form a cavity, the second electrode forms an outlet passage extending from the cavity, a maximum cross-sectional area of the cavity is greater than a minimum cross-sectional area of the outlet passage, and the first electrode and the second electrode are configured to ionize gas within the cavity in response to an electrical current applied to the first electrode or to the second electrode.

A combustor for a gas turbine system includes a combustor casing having an interior-establishing wall, and a chamber extending to the interior-establishing wall. In addition, the combustor includes an igniter assembly disposed within the chamber such that a tip of the igniter assembly is positioned radially outwardly from the interior-establishing wall. The igniter assembly includes a first electrode, a second electrode, and an insulator. In addition, the first electrode, the second electrode, and the insulator form a cavity, the second electrode forms an outlet passage extending from the cavity, a maximum cross-sectional area of the cavity is greater than a minimum cross-sectional area of the outlet passage, and the first electrode and the second electrode are configured to ionize gas within the cavity in response to an electrical current applied to the first electrode or to the second electrode.