Putt Putt Boat Steam Engine
For one of my projects in the design of thermal/fluids systems senior capstone class at Union College, I was part of a team that optimized the design of a putt-putt steam boat engine. The task was to design a boat that could carry the most payload, while at the same time, fast enough to beat our competitors in a race.
The hull and associated tail fins were 3D printed, whereas the steam engine was adapted from a commercial toy boat. Ice cubes were added to the engine design to enhance the thermal efficiency and increase thrust.