A circular window without tracery, such as are found in many Italian churches, is referred to as an ocular window or oculus.
The example created on this site is eventually mounted onto a home-built kart and tested* Pulsejets in aeromodels* Popular Rotocraft Association* Pulse Jet Bike* Apocalyptic robotics performance group Survival Research Labs operates a collection of pulse jet engines in some of their creations, including the Hovercraft, V1, and the Flame Hurricane.