Abstract:Micro-combustor features small size and compact layout, leading to poor heat dissipation. Applying ribbed cooling design to micro-turbojet engine combustion chambers significantly improves heat dissipation performance. A simplified model of the flame tube was established, with ribs added at different positions on flame tube walls. Three groups of ribs were arranged at varying positions to analyze the effects on airflow within combustor across an inlet velocity range of 10 m/s to 100 m/s, as well as the impact of different rib configurations on heat dissipation. Results show that adding ribs compresses airflow channels, causing acceleration in upstream sections. As airflow passes over ribs, compression effect diminishes, leading to reduced velocity. At the same inlet velocity, temperature variation in the third flame tube is greater, as ribs are closer to inlet and less affected by internal environment, providing better cooling. When ribs are positioned farther from airflow inlet, rear wall influence leads to more turbulent airflow and less stable heat dissipation. At lower airflow velocities, between 10 m/s and 60 m/s, rib cooling effect becomes more pronounced, but at higher velocities (60 m/s to 100 m/s), increased flow rate weakens cooling. These findings hold theoretical significance and practical value for ribbed heat dissipation structure design in micro-combustors.
