You probably won’t find the Humphrey cycle in your thermo book. It involves a slight (in theory) modification to the Brayton cycle. The heat is added at constant volume instead of constant pressure. Thus, the temperature rise in the combustion step is a factor of the ratio of specific heats higher than in the Brayton cycle. You will find that the increase in entropy is lower than that in the Brayton cycle and the cycle efficiency is correspondingly higher. If the practicalities can be worked out, the Humphrey cycle will be a “game changer.”