Quizlexic

X can also be used in a monopropellant rocket. In the presence of a heated catalyst, X will decompose exothermically into nitrogen and oxygen, at a temperature of approximately 1300 °C. Because of the large heat release the catalytic action rapidly becomes secondary as thermal autodecomposition becomes dominant. In a vacuum thruster, this can provide a monopropellant specific impulse (Isp) of as much as 180s. While noticeably less than the Isp available from hydrazine thrusters (monopropellant or bipropellant), the decreased toxicity makes X an option worth investigating. Because of its release of very high temperature oxygen as a monopropellant the addition of even small amounts of a fuel such as hydrogen rapidly increases the specific impulse and the high oxygen temperatures simplify ignition of the fuel. Isp greater than 340 seconds can be readily achieved[citation needed]. Its low freezing point also eases thermal management as compared to hydrazine—a valuable property on a spacecraft which may contain quantities of cryogenic propellant.

X is stored as a compressed liquid; the evaporation and expansion of liquid X in the intake manifold causes a large drop in intake charge temperature, resulting in a denser charge, further allowing more air/fuel mixture to enter the cylinder.X is sometimes injected into (or prior to) the intake manifold, whereas other systems directly inject right before the cylinder (direct port injection) to increase power.

One of the major problems of using X in a reciprocating engine is that it can produce enough power to damage or destroy the engine. Very large power increases are possible, and if the mechanical structure of the engine is not properly reinforced, the engine may be severely damaged or destroyed during this kind of operation. It is very important with X augmentation of internal combustion engines to maintain proper operating temperatures and fuel levels to prevent "preignition", or "detonation" (sometimes referred to as "knocking" or "pinging"). Most problems that are associated with X do not come from mechanical failure due to the power increases. Since X allows a much denser charge into the cylinder it dramatically increases cylinder pressures. The increased pressure results in heat, and heat will cause many problems from melting the piston, valves or warping the head/cracking or predetonation.

What Is X?