Expander rocket cycle. Expander rocket engine (closed cycle). Heat from the nozzle and combustion chamber powers the fuel and oxidizer pumps.
The expander cycle is a power cycle of a bipropellant rocket engine. In this cycle, the fuel is used to cool the engine's combustion chamber, picking up heat and changing phase. The now heated and gaseous fuel then powers the turbine that drives the engine's fuel and oxidizer pumps before being injected into the combustion chamber and burned.
Because of the necessary phase change, the expander cycle is thrust limited by the square–cube law. When a bell-shaped nozzle is scaled, the nozzle surface area with which to heat the fuel increases as the square of the radius, but the volume of fuel to be heated increases as the cube of the radius. Thus beyond approximately 300 kN (70,000 lbf) of thrust, there is no longer enough nozzle area to heat enough fuel to drive the turbines and hence the fuel pumps. Higher thrust levels can be achieved using a bypass expander cycle where a portion of the fuel bypasses the turbine and or thrust chamber cooling passages and goes directly to the main chamber injector. Non-toroidal aerospike engines are not subject to the limitations from the square-cube law because the engine's linear shape does not scale isometrically: the fuel flow and nozzle area scale linearly with the engine's width. All expander cycle engines need to use a cryogenic fuel such as liquid hydrogen, liquid methane, or liquid propane that easily reaches its boiling point.
Some expander cycle engines may use a gas generator of some kind to start the turbine and run the engine until the heat input from the thrust chamber and nozzle skirt increases as the chamber pressure builds up.
Some examples of an expander cycle engine are the Aerojet Rocketdyne RL10 and the Vinci engine for the future Ariane 6.[1]
^"Ariane 6". www.esa.int. Retrieved 21 February 2017.
The expandercycle is a power cycle of a bipropellant rocket engine. In this cycle, the fuel is used to cool the engine's combustion chamber, picking up...
separate piston compressor and piston expander, with compressed air heated by internal fire as it entered the expander cylinder. The first versions of the...
pump-fed. Pump-fed engines work in a gas-generator cycle, a staged-combustion cycle, or an expandercycle. Gas-generator engines tend to be used on booster...
example, the RD-180 and RS-25 use boost pumps driven by tap-off and expandercycles, as well as pressurized tanks, to incrementally increase propellant...
positive displacement compressor+expander below 100 kW. With high temperature hydraulic fluid, both the compressor and the expander can be liquid-ring pumps even...
exhaust that can be supplied to a turbine expander operating at a pressure ratio between 6 and 12. The expander discharge leaves as a subcritical CO2 mixture...
theory, an expander graph is a sparse graph that has strong connectivity properties, quantified using vertex, edge or spectral expansion. Expander constructions...
The ATREX engine (Air Turbo Ramjet Engine with eXpandercycle) developed in Japan is an experimental precooled jet engine that works as a turbojet at low...
the Space Launch System and the Centaur V of the Vulcan rocket. The expandercycle that the engine uses drives the turbopump with waste heat absorbed by...
screw, scroll, or other expander), and then through a condenser heat exchanger where it is finally re-condensed. In the ideal cycle described by the engine's...
liquid hydrogen and liquid oxygen propellants. The engine runs on an expandercycle, running the turbopumps with waste heat absorbed from the main combustion...
to as a turbo-expander or an expansion turbine, is a centrifugal or axial-flow turbine, through which a high-pressure gas is expanded to produce work...
to work both in open-cycle mode as a nuclear thermal engine during mission phases requiring high thrust, as well as in closed-cycle mode as a nuclear-electric...
stream is dumped overboard. Turboexpander Gas-generator cycle Staged combustion cycleExpandercycle Components of jet engines Neufeld, Michael J. (1995)...
cycle continuously (see cycle diagram at right margin). At the start of the cycle, during ventricular diastole–early, the heart relaxes and expands while...
co-orbiting or spinning reversible steam expander driven by a fixed radius crank on a single shaft. However, the scroll expander engine could not overcome the machining...
boron-containing structure. That energy is put through a closed-loop Brayton cycle generator to transform it into electricity for use in energizing the coils...
Global Information