Engine mixing structures

1. A mixing structure, comprising:

a body defining an axis and extending from an injector side toward an opposite piston side along the axis, the body having an inward facing surface proximate to the axis that defines a central volume and an outward facing surface distal from the axis, the injector side of the body is configured to face a fuel injector of a cylinder of an engine while the piston side of the body is configured to face a piston head of the engine cylinder, and

the body has undulating fins spaced apart from each other around the axis of the body and around the central volume to define gas channels radially extending through the body from outside of the body to the central volume, the undulating fins elongated in directions parallel to the axis of the body, and

the body has one or more conduit surfaces that define one or more fuel-and-gas mixture conduits extending through the body to and from the central volume, and

the central volume is configured to receive one or more streams of fuel from the fuel injector, and one or more streams of gas from the gas channels, and

during operation, at least one of the streams of the fuel mixes with the one or more streams of gas to form a fuel-and-gas mixture at a designated ratio of fuel to gas, and

the fuel-and-gas mixture conduits are configured to direct the fuel-and-gas mixture out of the body and into a combustion chamber of the engine cylinder.

2. The mixing structure of claim 1 , wherein the body is a single, monolithic, seamless structure.

3. The mixing structure of claim 1 , wherein the gas channels extend through the body such that the gas is drawn from the outside of the body into the central volume of the body.

4. The mixing structure of claim 1 , wherein the designated ratio of the fuel-and-gas mixture is controlled based on at least one of a number, shape, location, or size of one or more of the gas channels or the mixture conduits.

5. The mixing structure of claim 1 , wherein the gas channels have undulating shapes in the body between the outward facing surface and the inward facing surface of the body.

6. The mixing structure of claim 1 , wherein each of the mixture conduits is configured to create one or more of spin, swirl, or turbulence in the fuel-and-gas mixture flowing therethrough.

7. The mixing structure of claim 1 , wherein the mixture conduits extend radially outward from the axis and are configured that each stream of the fuel-and-gas mixture is centered in the mixture conduit in which the stream of the fuel-and-gas mixture flows.

8. The mixing structure of claim 1 , wherein the injector side of the body defines a step portion to avoid contact between the body and one or more inlet or outlet valves of the engine cylinder during operation of the engine.

9. The mixing structure of claim 1 , wherein at least a portion of the body is surface treated or coated.

10. A mixing structure, comprising:

a body configured to be positioned between a fuel injector and a cylinder of an engine along an axis of the body, the body defining an interior volume and having undulating fins that are spaced apart from each other around the axis of the body and around the interior volume, the undulating fins defining gas channels radially extending through the body from outside of the body to the interior volume, the undulating fins elongated in directions that are parallel to the axis of the body, the interior volume of the body configured to receive gas from outside the body through the gas channels and to receive one or more streams of fuel from the fuel injector in the interior volume, and

the body defining one or more mixture conduits configured to conduct plumes of the fuel and gas, while mixing, from the interior volume to one or more exit ports and therethrough to the cylinder.

11. The mixing structure of claim 10 , wherein the undulating fins of the body are configured to cool the gas prior to or during the mixture of the gas and the fuel in the interior volume and the one or more mixture conduits.

12. The mixing structure of claim 10 , wherein the body has an interface structure that defines at least one alignment hole or an alignment pin, and whereby the mixture conduits each align with a nozzle of the fuel injector.

13. The mixing structure of claim 12 , wherein the interface structure is shrink fit, press fit, welded, bolted to, threaded to, or formed as part of a cylinder head of the engine cylinder.

14. The mixing structure of claim 10 , wherein the mixture conduits define one or more apertures that connect to the gas channels, and the mixture conduits are configured to direct flows of the gas from the gas channels into the mixture conduit during operation of the cylinder.

15. The mixing structure of claim 10 , wherein each of the mixture conduits includes one or more dimples, textured surfaces, grooves or protuberances to facilitate mixing of the fuel and gas plumes flowing through the mixture conduits.

16. The mixing structure of claim 10 , wherein the mixture conduits are configured to mix the fuel and gas to a homogeneous state prior to combustion of the plumes in the cylinder.

17. The mixing structure of claim 16 , wherein the mixture conduits are configured to direct the plumes into the cylinder such that, relative to combustion in the cylinder without mixing the fuel and the gas to the homogeneous state, a relatively reduced amount or no amount of soot, nitrous oxides, or both soot and nitrous oxides are produced in the cylinder.

18. The mixing structure of claim 10 , wherein the body has a step portion to extend a path length of the one or more mixture conduits while avoiding contact of the body with one or more valves of the engine cylinder.

19. A mixing structure, comprising:

means for separately receiving fuel from a fuel injector and receiving gas, the means for separately receiving the fuel and receiving the gas including undulating fins that are spaced apart from each other around an axis, the undulating fins defining radially extending gas channels that are elongated in directions that are parallel to the axis;

means for mixing the fuel and the gas into a fuel-and-gas mixture at a designated ratio; and

means for directing the fuel-and-gas mixture into a combustion chamber of an engine cylinder.

20. The mixing structure of claim 19 , wherein the means for separately receiving the fuel and receiving the gas cools the gas prior to or while the gas is mixing with the fuel.

21. The mixing structure of claim 19 , wherein the means for mixing the fuel and the gas into the fuel-and-gas mixture comprises:

a mixture conduit having inner walls and means for inducing turbulence into fuel and gas streams to increase homogeneity of the fuel-and-gas mixture, and

means for centering and spacing a flow of the fuel-and-gas mixture from the inner walls of the mixture conduit.

22. The mixing structure of claim 19 , wherein the means for directing the fuel-and-gas mixture into the combustion chamber:

directs the fuel-and-gas mixture to penetrate into the combustion chamber of the engine cylinder prior to combustion, or

delays the combustion of the fuel-and-gas mixture, or

both directs the fuel-and-gas mixture into the combustion chamber of the engine cylinder prior to combustion and delays the combustion of the fuel-and-gas mixture.