RocketEngines: Difference between revisions
m typo fix |
New colon on soyuz engine and new ignition row. |
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| Line 10: | Line 10: | ||
|'''Company''' | |'''Company''' | ||
!Rocketdyne | !Rocketdyne | ||
!NPO Energomash | |||
!XCOR | !XCOR | ||
!XCOR | !XCOR | ||
| Line 16: | Line 17: | ||
|'''Model''' | |'''Model''' | ||
|[http://en.wikipedia.org/wiki/SSME SSME] | |[http://en.wikipedia.org/wiki/SSME SSME] | ||
|[http://www.astronautix.com/engines/rd178d74.htm RD-107] series (Soyuz) | |||
|[http://www.xcor.com/products/engines/4A3_LOX_alcohol_rocket_engine.html XR-4A3 (EZ-rocket)] | |[http://www.xcor.com/products/engines/4A3_LOX_alcohol_rocket_engine.html XR-4A3 (EZ-rocket)] | ||
|[http://www.xcor.com/products/engines/5K18_LOX-kerosene_rocket_engine.html XR-5K18 (Lynx)] | |[http://www.xcor.com/products/engines/5K18_LOX-kerosene_rocket_engine.html XR-5K18 (Lynx)] | ||
| Line 24: | Line 26: | ||
|'''Propellants''' | |'''Propellants''' | ||
|LOX & LH2 | |LOX & LH2 | ||
|LOX & Kerosene | |||
|LOX & Alcohol | |LOX & Alcohol | ||
|LOX & Kerosene | |LOX & Kerosene | ||
| Line 30: | Line 33: | ||
|'''Tank pressurization''' | |'''Tank pressurization''' | ||
|Yes, with O2 and H2 gases | |Yes, with O2 and H2 gases | ||
|Yes, with Nitrogen | |||
|No | |No | ||
|No | |No | ||
| Line 36: | Line 40: | ||
|'''Fuel pump''' | |'''Fuel pump''' | ||
|Turbopump | |Turbopump | ||
|Turbopump driven by gaz generator using hydrogen peroxide decomposition | |||
|Piston pump | |Piston pump | ||
|Piston pump | |Piston pump | ||
| Line 42: | Line 47: | ||
|'''Cooling''' | |'''Cooling''' | ||
|Regenerative w/ LH2 in three stages | |Regenerative w/ LH2 in three stages | ||
|Regenerative? | |||
|Regenerative (w/ Alcohol?) | |Regenerative (w/ Alcohol?) | ||
|Regenerative w/ Kerosene | |Regenerative w/ Kerosene | ||
| Line 48: | Line 54: | ||
|'''Chamber metal''' | |'''Chamber metal''' | ||
|Copper or iron? | |Copper or iron? | ||
|Copper? | |||
|Copper | |Copper | ||
|Copper | |Copper | ||
|? | |||
|- | |||
|'''Ignition system''' | |||
|? | |||
|Pyrotechnic, soon hypergolic | |||
|? | |||
|? | |||
|? | |? | ||
|- | |- | ||
| Line 56: | Line 70: | ||
|'''Energy''' | |'''Energy''' | ||
|Hydraulic | |Hydraulic | ||
|? | |||
| | | | ||
| | | | ||
| Line 62: | Line 77: | ||
|'''Provided by''' | |'''Provided by''' | ||
|Engine's turbopumps | |Engine's turbopumps | ||
|? | |||
| | | | ||
| | | | ||
| Line 68: | Line 84: | ||
|'''Actuator''' | |'''Actuator''' | ||
|six hydraulic servoactuators | |six hydraulic servoactuators | ||
|? | |||
|None | |None | ||
|None | |None | ||
| Line 76: | Line 93: | ||
|'''Valves''' | |'''Valves''' | ||
|Hydraulically or pneumatically (helium) actuated | |Hydraulically or pneumatically (helium) actuated | ||
|? | |||
|? | |? | ||
|? | |? | ||
Revision as of 08:24, 17 November 2010
Rocket Engine
The general principle may be simple, but there are numerous ways of achieving it. Different features and properties differ between existing rocket engines, and they all have consequences on complexity of manufacturing, complexity of operation, cost and weight for example.
We gather in this table the main properties of existing rocket engines.
| Company | Rocketdyne | NPO Energomash | XCOR | XCOR | Armadillo |
|---|---|---|---|---|---|
| Model | SSME | RD-107 series (Soyuz) | XR-4A3 (EZ-rocket) | XR-5K18 (Lynx) | LOX/methane (no name) |
| Combustion | |||||
| Propellants | LOX & LH2 | LOX & Kerosene | LOX & Alcohol | LOX & Kerosene | LOX & LCH4 |
| Tank pressurization | Yes, with O2 and H2 gases | Yes, with Nitrogen | No | No | Yes, with Helium |
| Fuel pump | Turbopump | Turbopump driven by gaz generator using hydrogen peroxide decomposition | Piston pump | Piston pump | No |
| Cooling | Regenerative w/ LH2 in three stages | Regenerative? | Regenerative (w/ Alcohol?) | Regenerative w/ Kerosene | ? |
| Chamber metal | Copper or iron? | Copper? | Copper | Copper | ? |
| Ignition system | ? | Pyrotechnic, soon hypergolic | ? | ? | ? |
| Actuators | |||||
| Energy | Hydraulic | ? | Electric | ||
| Provided by | Engine's turbopumps | ? | ? | ||
| Actuator | six hydraulic servoactuators | ? | None | None | Servo-motor |
| Others | |||||
| Valves | Hydraulically or pneumatically (helium) actuated | ? | ? | ? | ? |
Pumps and tank pressurization
In order to get fuel from the tanks into the combustion chamber, the tanks must be either pressurized or the fuels pumped. In some cases, both techniques are used. The choice for this concern has a large impact on the design of the engine's hardware, and the complexity of manufacturing and operations.
Traditionnaly, only turbo pumps have been able to feed the engine at a large enough rate. Innovative solutions appeared in research projects or private space projects, like the use of piston pumps for LOX or simple pressurization using liquid helium.
Several possibilities exist for tank pressurization:
- vaporization of liquid propellants back into their own tanks
- external vaporization of inert gas like Helium (can Nitrogen be used for that?)
- smoke generator, that basically react fuel and oxidizer and use the resulting smoke for pressurization.
Cooling
Regenerative cooling is most widely used in rocket engines.
Few of them however use other ways, like ablatively cooling carbon fiber composite in SpaceX Merlin 1A engine, or radiative cooling in the Merlin Vacuum nozzle (still regenerative for the chamber).
