An “airfryer” is a sort of convection oven that rapidly achieves frying-like results by blowing hot air over the food at very high speed, browning the surface. It occurred to me that you could, similarly, use high-speed pumped water circulation to rapidly heat food to boiling, or with some pressure, a bit higher than boiling. You can't brown the surface but you can cook the food.
This may be less of a difference from regular cooking (than an airfryer) because the bubbles rising in a boiling pot already produce substantial water circulation, far more than the air convection in a conventional oven; also, the water’s thermal conductivity and specific heat are much higher and close to the food’s, so perhaps in a boiling pot heat is already being transferred to the food so rapidly that most of the thermal resistance is in the food, not the heat transfer medium.