Magnetohydrodynamics Energy Bypass Scramjet Performance with Real Gas Effects

The theoretical performance of a scramjet propulsion system incorporating a magnetohydrodynamic (MHD) energy bypass scheme is calculated. The one-dimensional analysis developed earlier, in which the theoretical performance is calculated neglecting skin friction and using a sudden-freezing approximation for the nozzle e ow, ismodie edtoincorporatethemethodofVanDriestforturbulentskinfrictionandae nite-ratechemistrycalculation inthenozzle.Unlikeintheearlierdesign,inwhichfourrampcompressionsoccurredinthepitchplane,inthepresent design the e rst two ramp compressions occur in the pitch plane, and the next two compressions occur in the yaw plane.Theresultsforthesimplie ed designofaspacelinershowthat1 )skinfrictionsubstantiallyreducesthrustand specie cimpulse and 2 )the specie c impulseof the MHD-bypass system isstill betterthan the non-MHD system and typicalrocketoverarangeofe ightspeedsanddesignparameters.Resultssuggestthattheenergymanagementwith MHD principles offers the possibility of improving the performance of the scramjet for the spaceliner application and for the globecruiser application. The technical issues needing further studies are identie ed.