@article{article_1649340, title={Investigations on Ideal Inverted Brayton Cycle Engines}, journal={International Journal of Thermodynamics}, pages={1–8}, year={2025}, author={Karabacak, Mustafa and Turan, Onder}, keywords={T-S and P-V diagram, inverted Brayton cycle, thermodynamic cycle investigation}, abstract={In this study, T-S and P-V diagrams of the ideal inverted Brayton cycle engine are obtained by using numerical methods in Matlab® environment. The thermodynamic analysis of the inverted Brayton cycle engine is carried out to determine the limitations and development possibilities of this engine type and thus to guide the designer in this field. In the T-S and P-V diagram analysis, many findings about the limits and potential of the engine are obtained. It is observed that in the inverted Brayton cycle engine, unlike the Brayton cycle engine, there is no optimum compressor pressure ratio and the specific work increases as the compressor pressure ratio increases. Regardless of the flight Mach number, entropy generation in the afterburner is approximately 800 J/(kg·K), and entropy destruction in the cooling section is approximately 1000 J/(kg·K). Entropy generation in the preburner decreases from around 1800 J/(kg·K) under takeoff conditions to nearly zero during hypersonic flight, in parallel with the ram compression taking over the function of the preburner.}, number={Erken Görünüm - Early Pub Issues}, publisher={Uluslararası Uygulamalı Termodinamik Derneği İktisadi İşletmesi}