Thermodynamic analysis for recuperation in a scramjet nozzle with wall cooling

A thermodynamic analysis for recuperation in a scramjet nozzle with wall cooling was completed in this paper. The expansion process with recuperation was descripted using both diagrams and equations. A quasi-one-dimensional expansion model coupled with wall cooling was developed to support the description of the expansion process with recuperation, which consisted of two forms, namely, the fully cooled nozzle and the partially cooled nozzle. The results show that the recuperation process achieved by wall cooling in the nozzle has the potential to improve the performance of scramjets effectively. For both of two nozzle forms, the exhaust temperature and the area ratio of nozzle decrease with the regenerator effectiveness, and meanwhile the exhaust velocity increases when more heat is transferred back to combustor. The gains of specific impulse will be 16.24% and 22.57% for the fully cooled nozzle and the partially cooled nozzle respectively, if the regenerator effectiveness can reach to 30%. When taking no account of the thermal protection, the partially cooled nozzle has a greater potential than the fully cooled nozzle. (C) 2017 Published by Elsevier Ltd.