US Patent 7871042 Hydrogen fueled blended wing body ring tank

A toroidal shaped or ring fuel tank located within the loft line of a blended wing body aircraft is disclosed. The ring tank may be used in an aircraft to store liquid hydrogen fuel with a reduced tank weight. The ring tank may be continuous with no tank end domes typically found on cylindrical pressure tanks, reducing tank weight for a given fuel volume. The ring tank configuration avoids increasing the aerodynamic shape of the aircraft and does not encroach on usable passenger or payload areas of the aircraft. In one example the ring tank may be configured in a nose down position such that the forward portion of the ring tank is outside the pressurized cabin area.