Abstract: A method for control of spark ignition in a spark-ignited internal combustion engine that includes an ignition plug and generates plasma to ignite an air-fuel mixture, where the plasma is caused by a reaction between a product resulting from spark discharge generated by a high voltage applied via an ignition coil connected to the ignition plug and an electric field generated in a combustion chamber by an electric generation means via the ignition plug, the method including generating the electric field by a positive pulsating current. Thus, the method allows a spark-ignited internal combustion engine to promote expansion of combustion after ignition.

Abstract: An object of the present invention is to provide a barrier discharge device capable of increasing the combustion efficiency of an engine while overcoming the problems of the cumbersome replacement of the electrodes and the commercialization of the device. The barrier discharge device of an engine includes a dielectric body and at least two barrier discharge electrodes which are held inside the dielectric body and to which voltages for barrier discharge are applied, wherein each of the barrier discharge electrodes are not exposed to the inside of a cylinder bore and are arranged so as to surround the cylinder bore.

Abstract: A power-generating system includes a heat source having a temperature that goes up and down over time; a first device that undergoes electric polarization due to a temperature change of the heat source; and a second device that takes out an electric power from the first device.

Abstract: Provided is a method for determining a combustion state of a spark-ignited internal combustion engine including an ignition plug to ignite a fuel-air mixture by a plasma generated by a reaction between a spark discharge generated by a high voltage applied through an ignition coil connected to the ignition plug and an electric field generated in a combustion chamber. In the method, a change in a secondary voltage secondarily generated in the ignition plug after the spark discharge in association with the spark discharge is detected. A case where the change in the detected secondary voltage deviates from a predetermined range is determined as an occurrence of misfire. This enables detection of a misfire state without being hindered from an ion current due to the plasma remaining in the combustion chamber.

Abstract: A plasma actuator (1) includes four electrodes (11) and three dielectrics (10) and is disposed on the side of an object surface (B). When a high voltage is applied to the electrodes (11), a plasma (15) is generated at an end (10a) of each dielectric (10) exposed so as to be accessible to a gas. In the plasma actuator (1), the electrodes (11) and dielectrics (10) are alternately stacked one on another. The plasma actuator (1) includes a stepped exposed portion (X). The plasma actuator (1) in which the electrodes (11) and dielectrics (10) are arranged such that the ends (10a) of the dielectrics (10) are exposed in the normal line direction of the object surface (B) in the stacked order in the stepped exposed portion (X) can suppress the flow of the generated plasma even when the plasma actuator is exposed to a high-speed airflow under high pressure. This stabilizes the plasma.

Abstract: A control method for a spark-ignited internal combustion engine includes generating plasma by interacting an electric field generated in a combustion chamber by electric field generation means with spark discharge caused by a spark plug, and igniting an air-fuel mixture, wherein the electric field generated by the electric field generation means is set to an intensity weaker than that of an electric field generated by the spark plug when the spark discharge is caused, and set to an intensity at which discharge into the combustion chamber is disabled, and the air-fuel mixture can be securely ignited and combusted at an intended ignition timing and at a position of the spark plug.

Abstract: A multicylinder internal combustion engine is provided with a plurality of cylinders sharing a single crankshaft. The combustion characteristics in the respective cylinders is improved by taking out part of combustion (expansion) gas produced in one of the cylinders at an earlier stage of the explosion (expansion) stroke, and then introducing the gas into another one of the cylinders in the suction or compression stroke.

Abstract: A multicylinder internal combustion engine is provided with a plurality of cylinders sharing a single crankshaft. The combustion characteristics in the respective cylinders is improved by taking out part of combustion (expansion) gas produced in one of the cylinders at an earlier stage of the explosion (expansion) stroke, and then introducing the gas into another one of the cylinders in the suction or compression stroke.