> From: [EMAIL PROTECTED] > Subject: [ERPS] Vanes, box shealding & landing frame > > John Carmack, > > I was wandering if you folks had any concerns about the deep > enclosure around the jet vanes? It seems to me it may cause > some problems with the gas dynamics for controlling the thrust > vectoring. It seems that as the vanes deflect a significant amount > the gases are going to impinge on the side of the box and basically > have the steering effects basically canceled out. Also it would > seem that at extreme vane deflection the back pressure behind and > to the side of the vane and the box could be the cause of the > stress failures of the shaft and vane that might not of other wise > have happened in such a constricted volume. >> ****************************************
The problem you describe has been dealt with in missles with steering vanes contained in a shroud. A recent AIAA article about this says the steering loss is about 30% or so. For John's rocket, the box-like structure surrounding the exhaust looks a lot larger than the exhaust diameter, so that kind of steering cancellation is less or nonexistant. The proof is probably in that it flew... Charles Pooley _______________________________________________ ERPS-list mailing list [EMAIL PROTECTED] http://lists.erps.org/mailman/listinfo/erps-list
