Abstract: A piston for a reciprocating piston machine includes a piston crown, a piston recess, and an annular groove formed in the piston crown. The annular groove extends in a radial direction of the piston outwards and a cross-section of the annular groove has a half-teardrop shape. The half-teardrop shape has a first radius and a second radius where the second radius is directly contiguous with the first radius outwards in the radial direction of the piston and where the second radius is greater than the first radius.

Abstract: A motor vehicle internal combustion engine has at least one combustion chamber delimited by at least one wall of the internal combustion engine, and at least one injector that is associated with the combustion chamber and that is at least partially accommodated in a receiving opening delimited by a first wall area of the wall extending at least essentially parallel to the axial direction of the injector The injector includes at least one injection opening that opens into the combustion chamber via the receiving opening, in the direction of the combustion chamber the first wall area being directly adjoined by a further wall area of the wall that extends at an angle to the axial direction and which delimits an at least essentially conical area of the receiving opening which expands toward the combustion chamber.

Abstract: A motor vehicle internal combustion engine has at least one combustion chamber delimited by at least one wall of the internal combustion engine, and at least one injector that is associated with the combustion chamber and that is at least partially accommodated in a receiving opening delimited by a first wall area of the wall extending at least essentially parallel to the axial direction of the injector The injector includes at least one injection opening that opens into the combustion chamber via the receiving opening, in the direction of the combustion chamber the first wall area being directly adjoined by a further wall area of the wall that extends at an angle to the axial direction and which delimits an at least essentially conical area of the receiving opening which expands toward the combustion chamber.

Abstract: A method for preventing flashback in a reaction chamber that includes providing a mixture of educts flowing through a mixture distribution zone and into the reaction chamber. The mixture distribution zone has an inlet opening and a variable flow cross-section between the inlet opening and the reaction chamber. The method also includes combusting the mixture in the reaction chamber at a combustion rate, and varying the flow cross-section as a function of a volume of the mixture so as to affect a flow rate of the mixture into the reaction chamber such that the flow rate is greater than the combustion rate. In addition, a reactor that includes, an inlet opening for receiving a mixture of educts, a mixture distribution zone disposed downstream of the inlet opening and having a variable flow cross-section, a reaction chamber disposed downstream of the mixture distribution zone, and a regulation device disposed in the mixture distribution zone for varying the flow cross section.