Gentlemen, there is a somewhat theoretical question. It is often assumed that for bigger (liquid) rockets it's easier to get the good mass ratio than for smaller one. Usually one says that the mass of, say, tanks - a major contributor to the rocket dry weight - is proportional to the second power of their size, while the weight of propellant, carried in them, is proportional to the third power.
At the same time, if the tanks are pressurized (and this reasoning should hold for all pressurized volumes), the thickness of the wall should be proportional to the tank size, because the same pressure over a bigger diameter produces the bigger force. So, where do the savings come from? Is it the case only for tanks with small inner pressure, so their wall thickness is determined by other considerations? It's also said that if an engine uses a higher chamber pressure, it has smaller and therefore lighter chamber. The same argument supposes that we'll need to make walls thicker, and that will cancel the gains from smaller chamber size. Alexander __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
