Internal combustion engine

1. An internal combustion engine for use with hydrogen fuel, the engine having at least one cylinder assembly, the or each cylinder assembly comprising:

a combustion chamber comprising a cylinder, a cylinder head and a reciprocating piston assembly, the cylinder defining a cylinder longitudinal axis;

a fuel injector for injecting fuel into the combustion chamber, the fuel injector defining an injector longitudinal axis; and

a fuel flow director, wherein the fuel flow director is located in a fuel flow path between an outlet of the fuel injector and the combustion chamber;

wherein the fuel injector is oriented such that the injector longitudinal axis extends at a first angle; and

wherein the fuel flow director is configured to direct fuel flow into the combustion chamber at a second angle, different than the first angle; and

further including a chamber disposed between the outlet of the fuel injector and an outlet aperture of the fuel flow director through which fuel leaves the chamber;

and further wherein the chamber has a volume and the outlet aperture of the fuel flow director has a cross-sectional area, and wherein a ratio of the volume of the chamber to the cross-sectional area of the outlet aperture area is in a range of 16:1 to 21:1.

2. The internal combustion engine according to claim 1 , wherein the fuel flow director comprises only a single outlet aperture.

3. The internal combustion engine according to claim 1 , wherein the fuel flow director includes a plurality of outlet apertures.

4. The internal combustion engine according to claim 1 , wherein the cylinder assembly further comprises a sleeve surrounding the fuel injector, and wherein the sleeve comprises the fuel flow director;

wherein the sleeve has a first portion that extends over the fuel injector, and a second portion that extends beyond the outlet of the fuel injector, wherein an end of the second portion of the sleeve comprises the fuel flow director; and

wherein the second portion of the sleeve defines the chamber between the fuel injector outlet and the fuel flow director.

5. The internal combustion engine according to claim 4 , wherein the cylinder assembly comprises a head adaptor for locating the fuel injector with respect to the cylinder head, and wherein the head adaptor is integral to the sleeve.

6. The internal combustion engine according to claim 4 , wherein the cylinder assembly comprises a sleeve location arrangement configured for the prevention of rotation of the sleeve about the fuel injector longitudinal axis, the sleeve location arrangement comprising a location feature defined by the sleeve and a corresponding location feature defined by the cylinder head.

7. The internal combustion engine according to claim 1 , wherein the fuel flow director is integral to the cylinder head.

8. The internal combustion engine according to claim 1 , wherein the cylinder head defines the chamber.

9. The internal combustion engine according to claim 1 , wherein the ratio of the chamber volume to the cross-sectional area of the outlet aperture is in the range of 17:1 to 19:1.

10. The internal combustion engine according to claim 1 , wherein the ratio of the chamber volume to the cross-sectional area of the outlet aperture is substantially 17.5:1.

11. The internal combustion engine according to claim 1 , wherein the outlet aperture is defined by an internal face, and wherein at least a portion of the internal face is at an angle substantially parallel to the second angle.

12. The internal combustion engine according to claim 11 , wherein the whole of the internal face is at an angle substantially parallel to the second angle.

13. The internal combustion engine according to claim 1 , wherein the first angle is a non-zero angle in relation to the cylinder longitudinal axis.

14. The internal combustion engine according to claim 5 , wherein the ratio of the chamber volume to the cross-sectional area of the outlet aperture is in the range of 17:1 to 19:1.

15. The internal combustion engine according to claim 8 , wherein the outlet aperture is defined by an internal face, and wherein at least a portion of the internal face is at an angle substantially parallel to the second angle.

16. An internal combustion engine for use with hydrogen fuel, the engine having at least one cylinder assembly, the or each cylinder assembly comprising:

a combustion chamber comprising a cylinder, a cylinder head and a reciprocating piston assembly, the cylinder defining a cylinder longitudinal axis;

a fuel injector for injecting fuel into the combustion chamber, the fuel injector defining an injector longitudinal axis;

wherein the fuel injector is oriented such that the injector longitudinal axis extends at a first angle; and

a fuel flow director, wherein the fuel flow director is located in the fuel flow path between an outlet of the fuel injector and the combustion chamber;

wherein the cylinder assembly further comprises a sleeve surrounding the fuel injector, and wherein the sleeve comprises the fuel flow director;

wherein the sleeve has a first end that extends over the fuel injector, and a second end that extends beyond an outlet of the fuel injector, wherein the second end of the sleeve comprises the fuel flow director;

wherein the second end of the sleeve defines a chamber between the fuel injector outlet and the fuel flow director, and an outlet aperture by which fuel leaves the chamber; and

wherein a ratio of the chamber volume to a cross-sectional area of the outlet aperture is in the range of 16:1 to 21:1.

17. The internal combustion engine according to claim 16 , wherein the ratio of the chamber volume to the cross-sectional area of the outlet aperture is in the range of 17:1 to 19:1.

18. The internal combustion engine according to claim 16 , wherein the outlet aperture is defined by an internal face, and wherein at least a portion of the internal face is at an angle substantially parallel to the second angle.

19. An internal combustion engine for use with hydrogen fuel, the engine having at least one cylinder assembly, the or each cylinder assembly comprising:

a combustion chamber comprising a cylinder, a cylinder head and a reciprocating piston assembly, the cylinder defining a cylinder longitudinal axis;

a fuel injector for injecting fuel into the combustion chamber, the fuel injector defining an injector longitudinal axis; and

a fuel flow director, wherein the fuel flow director is located in the fuel flow path between an outlet of the fuel injector and the combustion chamber;

wherein the fuel flow director is integral to the cylinder head;

wherein the cylinder head defines a chamber between the fuel injector outlet and the fuel flow director, and an outlet aperture by which fuel leaves the chamber; and

wherein the ratio of the chamber volume to the cross-sectional area of the outlet aperture is in the range of 16:1 to 21:1.