Abstract: The use of hydrocarbon fuels for cooling hypersonic aircraft and missile structures and engines is accomplished by passing fuel through cooling channels in the vehicle. A multicomponent hydrocarbon fuel having a pyrolyzing component which cracks in a supercritical temperature range (above 900.degree. F.) and thus absorbs heat is used in combination with a diluent fuel or fuel component which reduces the rate at which cracked hydrocarbons recombine in the cooling channels, thus causing coking which can clog cooling channels and also release heat to the structure to be cooled. The cracked fuel having absorbed heat and remaining in it's cracked state is in a condition to burn more quickly and energetically in the combustion chamber along with the hot diluent fuel, thus providing an efficient use of the heat absorbed in the cooling process and increasing the performance of the vehicle.

Abstract: To decrease the wear between the journal 6, and the hydrostatic bearing 1, especially during start up and shut down of the turbomachine, a rub ring 5, is employed intermediate the journal and bearing. The rub ring will come into contact with the journal before the bearing and prevent contact with the bearing bore. The rub ring also serves to block the leakage of the fluid from the bearing. This interrupted flow causes an increase in the stiffness and damping coefficients of the hydrostatic bearing. The use of the rub ring increases the life of the bearing, improves the rotordynamic performance, reduces the leakage flow and improves the hydrodynamic performance of the hydrostatic bearing.