Rocket engine injector
Disclosed herein are various technologies pertinent to rocket engines, including injector, thrust chamber, and electrical turbopump devices that may be combined to provide a more efficient rocket engine.
1. An apparatus comprising:
an injector for a rocket engine, the injector including:
a propellant distribution system; and
a base plate having a plurality of propellant port pairs including first propellant port pairs and second propellant port pairs, wherein:
the plurality of propellant port pairs includes a first plurality of the propellant port pairs in which there are equal numbers of the first propellant port pairs and the second propellant port pairs;
the propellant port pairs in the first plurality of propellant port pairs are arranged in a first circular array about a center axis with:
each first propellant port pair in the first plurality of propellant port pairs interposed between two adjacent second propellant port pairs in the first plurality of propellant port pairs,
each second propellant port pair in the first plurality of propellant port pairs interposed between two adjacent first propellant port pairs in the first plurality of propellant port pairs, and
the propellant port pairs in the first plurality of propellant port pairs evenly spaced about the center axis;
the two propellant ports in each propellant port pair in the plurality of propellant port pairs, including each propellant port pair in the first propellant port pairs and each propellant port pair in the second propellant port pairs, both have centerlines that lie along a corresponding plane that is parallel to and coincident with the center axis;
each propellant port pair includes two propellant ports that:
are angled such that fluid streams directed through the propellant ports in that propellant port pair meet and impinge on one another at a location spaced apart from a first side of the base plate, and
each extend between a corresponding opening on the first side of the base plate and another corresponding opening on a second side of the base plate opposite the first side of the base plate;
the corresponding openings of the propellant ports in each first propellant port pair that are on the second side of the base plate are fluidically connected with the propellant distribution system; and
each propellant port in each first propellant port pair is fluidically isolated within the injector from each propellant port in each second propellant port pair.
2. The apparatus of claim 1 , wherein the two propellant ports in each propellant port pair are at the same angle relative to a plane that is perpendicular to the center axis.
3. The apparatus of claim 1 , wherein:
the plurality of propellant port pairs further includes a second plurality of the propellant port pairs in which there are also equal numbers of the first propellant port pairs and the second propellant port pairs,
the propellant port pairs in the second plurality of propellant port pairs are arranged in a second circular array about the center axis with:
each first propellant port pair in the second plurality of propellant port pairs interposed between two adjacent second propellant port pairs in the second plurality of propellant port pairs,
each second propellant port pair in the second plurality of propellant port pairs interposed between two adjacent first propellant port pairs in the second plurality of propellant port pairs, and
the propellant port pairs in the second plurality of propellant port pairs evenly spaced about the center axis.
4. The apparatus of claim 3 , wherein the propellant port pairs in the first circular array are spaced farther from the center axis than the propellant port pairs in the second circular array.
5. The apparatus of claim 3 , wherein the base plate further includes a plurality of drip orifices, wherein:
each drip orifice extends through the base plate,
the drip orifices are arranged in a third circular array around the center axis, and
the drip orifices are spaced further from the center axis than the propellant port pairs in the first plurality of propellant port pairs and in the second plurality of propellant port pairs.
6. The apparatus of claim 5 , wherein the base plate further includes a plurality of propellant inlet ports, wherein:
each propellant inlet port extends through the base plate,
the propellant inlet ports are arranged in a fourth circular array around the center axis, and
the propellant inlet ports are spaced further from the center axis than the drip orifices.
7. The apparatus of claim 6 , wherein the propellant inlet ports and the drip orifices are positioned adjacent to an outer edge of the base plate.
8. The apparatus of claim 3 , wherein:
the injector further includes a plurality of column bases,
each column base joins the base plate,
a corresponding base plenum is defined between each column base and the base plate,
the base plenums are fluidically connected with the propellant distribution system, and
the openings of the propellant ports that are on the second side of the base plate and in each first propellant port pair are within a corresponding one of the base plenums.
9. The apparatus of claim 8 , wherein:
the injector further includes a plurality of support columns,
each support column is connected with one of the column bases, and
each support column includes a riser passage within it that fluidically connects the propellant distribution system with the base plenum partially defined by the column base to which that support column is attached.
10. The apparatus of claim 9 , wherein:
the propellant distribution system includes a first annular plenum and a second annular plenum,
the support columns connected with the column bases partially defining the base plenums corresponding to each first propellant port pair in the first plurality of propellant port pairs connect with the first annular plenum, and
the support columns connected with the column bases partially defining the base plenums corresponding to each first propellant port pair in the second plurality of propellant port pairs connect with the second annular plenum.
11. The apparatus of claim 10 , wherein the propellant distribution system further includes a plurality of first radial passages arranged in a circular array about the center axis, each first radial passage fluidically connecting the first annular plenum with the second annular plenum.
12. The apparatus of claim 11 , wherein the propellant distribution system further includes an annular propellant distribution plenum that encircles the first annular plenum and the second annular plenum.
13. The apparatus of claim 12 , wherein the propellant distribution system further includes a plurality of second radial passages arranged in a circular array about the center axis, each second radial passage fluidically connecting the first annular plenum with the annular propellant distribution plenum.
14. The apparatus of claim 3 , further comprising a cap that, in combination with the injector, defines a free volume at least partially bounded by the cap and the second side of the base plate.
15. The apparatus of claim 14 , wherein the cap includes an inlet that is positioned along the center axis.
16. The apparatus of claim 15 , further comprising a thrust chamber that is connected with the injector, wherein:
the thrust chamber includes a barrel section that transitions to a throat section having a smallest diameter of the thrust chamber,
the throat section transitions to an expansion section,
the first side of the base plate faces the throat section,
the barrel section is interposed between the throat section and the base plate, and
the throat section is interposed between the barrel section and the expansion section.
17. The apparatus of claim 16 , wherein the thrust chamber includes:
an exterior skin,
an interior skin offset from the exterior skin so as to form a first gap between the exterior skin and the interior skin, and
a plurality of walls bridging between the exterior skin and the interior skin and located within the first gap, wherein:
the walls define a plurality of coolant flow passages that extend from a first end of the thrust chamber to a second end of the thrust chamber that is coupled with the base plate, and
at least some portions of one or more of the coolant flow passages have a different surface roughness than at least some other portions of the one or more coolant flow passages.
18. The apparatus of claim 17 , wherein the surface roughness of the coolant flow passages is highest in the throat section.
19. The apparatus of claim 18 , wherein the surface roughness of the coolant flow passages in at least a portion of the throat section is 120 μm±15 μm and the surface roughness of the coolant flow passages in at least portions of the barrel section and the expansion section is 60 μm±15 μm.