Kazak писал(а):
Но мне интересно чем же они Вас привлекли? Я не вижу в них преимуществ, хотя и делаю ДУ.
Преимущества достаточно очевидны, недостатков, увы, тоже много.
Ну вот цитата из технионовской статьи THE STATUS OF GEL PROPELLANTS IN YEAR 2000 на этот счет:
Цитата:
Advantages of Gel Propellants in Comparison to Liquid and Solid Propellants
1. Safety aspects
Leaks and spill. The gel surface hardens in contact with a gaseous environment4. Hence, in cases of failure in the feeding system or during storage, the leakage rate is reduced, compared to liquids. In cases of accidental spillage due to damage in the fuel and oxidizer tanks, burning will occur only at the fueloxidizer interface, if they are hypergolic. When contact ceases, the rheological nature of the gels will prevent further flow and chemical reaction. The volatility of gels is significantly lower than the volatility of liquids and in case of leak or spill, much less vapors will be released, thus reducing toxicity hazards.
Sensitivity to impact, friction and electrostatic discharge: In comparison to solids where detonation, explosion or deflagration can take place, gels are insensitive, similar to liquids.
Accidental ignition. In comparison to solids where motor ignition can lead to a catastrophe, in gels, as in liquids, combustion is controllable and can be prevented.
Cracks. Unlike solids, in which cracks in the propellant grain increase burning area and can lead to uncontrolled combustion and explosion, gels are fed into the combustion chamber similar to liquids, thus cracks in the gel structure have no effect.
2. Performance aspects
Specific impulse. In general, it is similar to liquids and increases when metal particles are added.
Density impulse. Metallized gels have significantly improved density impulse in comparison to liquids, depending on the metal additive and its loading.
Energy management. Similar to liquids.
3. Storage aspects
Stability. Gels have demonstrated long term storage capability (more than 10 years)4-6.
Packing. Flexible packing, similar to liquids.
Particle sedimentation. In comparison to slurries, particle sedimentation is significantly lower and phase separation occurs only at very high acceleration levels5.