Flow field and combustion characteristics of integrated afterburner schemes based on elimination of residual swirl angle

As an innovative concept for new generation afterburners, component integration represents a key trend in afterburner development research. However, when the inlet section of the afterburner is moved forward to the exit of the turbine rotor, the incoming flow exhibits a larger residual swirl angle affecting the performance. Three strut schemes for swirl elimination, Benchmark Strut (BS), Leading-Edge Twisted Strut (LETS) and Main-Wing Dual Struts (MWDS), are numerically investigated in this work. The non-reacting flow fields and fuel distribution, and reacting flow temperature and strut flame stabilizer’s wall temperature distribution are analyzed under the condition of different residual swirl intensities characterized by residual swirl angle variations. Results show that all three struts significantly reduce residual swirl intensity. Notably, MWDS is the least sensitive to residual swirl angle changes, effectively stabilizing the post-strut flow field. For each scheme, the total pressure recovery coefficient and combustion efficiency exhibit an inverse relationship with the variation of the residual swirl angle. Under strong residual swirl, BS and LETS have advantages in combustion efficiency due to enhanced fuel-air mixing (0.8% and 1.1% higher than MWDS, respectively), whereas MWDS is superior in terms of total pressure recovery coefficient (2.7% and 0.3% higher than BS and LETS, respectively) and thermal protection capability of the strut’s U-shaped surface (with average wall temperatures 8.9% and 2.6% lower than those of BS and LETS, respectively). These findings provide exploratory schemes for balancing multi-performance indicators in integrated afterburner when faced with residual swirl inflow, which is conducive to its further development.