Rocket motor combustion chamber injection head
An injection head including an annular distribution cavity for distributing a propellant upstream from an injection plate supporting injectors. The cavity includes a multiply-perforated distribution grid distributing the propellant, which grid is coaxial with the distribution cavity and of a concave shape that projects into the distribution cavity, the grid being fastened to a dome of the cavity.
1. An injection head for a rocket engine combustion chamber, the injection head comprising:
a substantially semi-toroidal shaped dome having a longitudinal central axis, the substantially semi-toroidal shaped dome generated by rotating a half-ellipse about the longitudinal central axis;
a single feed duct for feeding a propellant;
a distribution cavity for the propellant, the distribution cavity being annular and coaxial with the longitudinal central axis;
an injection plate including holes pierced therein for receiving injectors to inject the propellant into the rocket engine combustion chamber, the substantially semi-toroidal shaped dome and the injection plate enclosing the distribution cavity; and
a multiply-perforated distribution grid for distributing the propellant through multiple orifices, the distribution grid is annular, substantially semi-toroidal in shape and coaxial with the longitudinal central axis, the distribution grid projects into the distribution cavity with a concave shape, the distribution grid is fastened to a top inner surface of the substantially semi-toroidal shaped dome forming an annular propellant channel between the top inner surface and the distribution grid, the single feed duct opening out into the annular propellant channel, and the distribution grid is interposed in a stream of the propellant between the single feed duct and the injection plate.
2. An injection head according to claim 1 , wherein the distribution grid is perforated in a non-uniform manner.
3. An injection head according to claim 2 , wherein a flow area of the orifices varies over a surface of the grid.
4. An injection head according to claim 3 , wherein the flow area of the orifices increases going further away from the feed duct.
5. An injection head according to claim 2 , wherein density of the orifices varies over a surface of the grid.
6. An injection head according to claim 5 , wherein the density of the orifices increases going away from the feed duct.
7. An injection head according to claim 1 , wherein the distribution grid is of constant cross-sectional flow area.
8. An injection head according to claim 1 , wherein the distribution grid is of varying cross-sectional flow area.
9. An injection head according to claim 8 , wherein the cross-sectional flow area of the distribution grid diminishes going away from the feed duct.
10. An injection head according to claim 1 , wherein the feed duct is positioned on a top of the dome of the distribution cavity and is substantially perpendicular to the top of the dome.
11. An injection head according to claim 1 , wherein the feed duct is positioned in off-center manner on the dome of the distribution cavity relative to a perpendicular to a top of the dome and the feed duct forms an angle of about 15° to 20° with the perpendicular to the top of the dome.
12. A rocket engine comprising an injection head according to claim 1 .