Editing Liquid air cycle engine (section)

==Principle of operation==

Conceptually, LACE works by compressing and then quickly liquefying the air. Compression is achieved through the ram-air effect in an intake similar to that found on a high-speed aircraft like [[Concorde]], where [[intake ramp]]s create [[shock wave]]s that compress the air. The LACE design then blows the compressed air over a [[heat exchanger]], in which the [[liquid hydrogen]] fuel is flowing. This rapidly cools the air, and the various constituents quickly liquefy. By careful mechanical arrangement the liquid oxygen can be removed from the other parts of the air, notably [[water]], [[nitrogen]] and [[carbon dioxide]], at which point the liquid oxygen can be fed into the engine as usual.  It  will  be  seen that  heat-exchanger limitations always cause this system to run with a hydrogen/air  ratio  much  richer  than  stoichiometric  with  a  consequent  penalty  in  performance<ref>{{Cite web |url=https://www.flightglobal.com/FlightPDFArchive/1963/1963%20-%202241.PDF |title=Archived copy |access-date=2019-05-27 |archive-date=2015-02-13 |archive-url=https://web.archive.org/web/20150213054032/http://www.flightglobal.com/FlightPDFArchive/1963/1963%20-%202241.PDF |url-status=dead }}</ref> and thus some hydrogen is dumped overboard.