One-Dimensional Design of a Reverse-Flow Annular Combustor for a Micro Turbojet Engine: Methodology and Worked Example

This technical report documents a complete one-dimensional design methodology for the reverse-flow annular combustor of an 80 N-class micro turbojet intended for a fixed-wing logistics unmanned aerial vehicle, and presents a fully worked design example. The design chain covers: engine cycle definition and combustor design point; liner and casing geometry sizing; five-path airflow allocation with a forward hole-row design chain closed by two rounds of discharge-coefficient feedback; pressure-swirl atomizer sizing with SMD and evaporation checks; station-by-station wall-temperature prediction for a TBC-plus-metal liner; creep-based material allowables; and off-design verification including idle lean-blowout margin. All quantitative results are generated by the author's openly maintained design suite at github.com/yybelinda/microgt-combustor-1d. The computations reported here were performed with a modified version of this repository: the forward hole-row design chain with discharge-coefficient feedback and the station-based wall-temperature solve supersede the earlier implementations. Readers interested in the implementation details are referred directly to the repository. The report is intended for engineers performing preliminary combustor design for small gas turbines, and as supporting material for research collaboration inquiries.