Comparison and Analysis of Multi-Scheme Installation Layout of Over-Under TBCC
In view of the difficulties in installation and force transmission of over-under TBCC engine due to dual power,dual chan-nel,and geometric asymmetry,three different installation units,namely,Gas turbine,ramjet combustor,and single expansion ramp nozzle(SERN),were selected as the research objects.According to the connection combination form of the three installation units and the different layout forms of installation nodes,six different installation schemes were designed,and the load transfer characteristics and laws of differ-ent installation schemes under maneuver load and aerodynamic load were analyzed.The results show that the mechanical characteristics of the fully flexible scheme and ramjet+SERN rigid connection scheme are similar,so are the fully rigid scheme and turbine+SERN rigid con-nection scheme;The fully flexible scheme has the maximum stress on the main mount;The force transmission of the fully rigid scheme is better than that of the fully flexible scheme.Compared with the latter,the former reduces the force on the main mount by 57%under limited load and 55%under ultimate load;In the fully rigid scheme,the main mount is better placed on the turbine unit than on the SREN.