COMPARISON OF DIFFERENT LIQUID-HYDROGEN TANK INTEGRATION CONCEPTS FORTHE ELAC-1 RESEARCH CONFIGURATION

One of the main problems associated with the structural design of a hy personic aircraft is the conception of the cryogenic tank. Therefore t wo essential questions, in consideration of structural weight, volumet ric efficiency and the aspects as well of inspection, maintenance and repair, as of exchangeability in case of leakage (leak before burst) a nd safety in operation, have to be answered. These questions concern t he choice of the tank integration concept and the tank cross section. To get an idea how much the take-off weight depends on the tank integr ation concept, at the Institut fur Leichtbau of the RWTH Aachen a prog ram for weight estimation of hypersonic aircraft has been developed. H erewith the goal was to define well suited substitute models which all ow the performance of parametric studies within a wide range of parame ters in a tolerable amount of time. In the following the mass model an d calculation methods used will be shortly introduced and finally the results achieved will be presented and discussed. On this occasion als o comments on structural efficiency of different tank cross sections w ill be given.