Rocket engine efficiencies are much better, up to 70 %, because they operate at very high temperatures and pressures and can have very high expansion ratios.
32.
The rigidly mounted heatshield caused the underside of the rear fuselage to deform because the steel and the duralumin skin of the fuselage had different expansion ratios when heated.
33.
The effective compression ratio is reduced ( for the time the air is escaping the cylinder freely rather than being compressed ), but the expansion ratio is unchanged.
34.
Since the liquid to gas expansion ratio of this substance is 1 : 694, a tremendous amount of force can be generated if liquid nitrogen is rapidly vaporized.
35.
Also, increased mechanical efficiency is created by a higher compression ratio through the concomitant higher expansion ratio on the power stroke, which is by far the greater effect.
36.
In such a case, owing to the very great expansion ratio, the exhaust mixture will be at a relatively low temperature and suitable for admission to the condenser.
37.
For any given portion of air, the greater expansion ratio allows more energy to be converted from heat to useful mechanical energy, meaning the engine is more efficient.
38.
Many designs for space planes with scramjet engines make use of SERNs because of the weight reduction at large expansion ratios, or the additional lift at under-expansion.
39.
An Atkinson cycle engine uses the timing of the valve events to produce the benefits of a high expansion ratio without the disadvantages, chiefly detonation, of a high compression ratio.
40.
There is, however, a rise in nozzle pressure, because overall pressure ratio increases faster than the turbine expansion ratio, causing an increase in the hot mixer entry pressure.
