A dynamometer is an important tool for studying liquid piston engines (or any kind of engine, for that matter) . A dynamometer allows us to run the engine under varying external loads and also to measure the power produced by the engine. All kinds of dynamometers have been developed over the years suited to many different engines and purposes. While the testing of the solar-powered engine discussed in my last post provided the proof-of-concept, and yielded some useful operational information, the fact that the engine ran completely unloaded (only operating against internal friction) imposed a pretty severe limitation on the amount and usefulness of the information that could be learned. Essentially, it would be like evaluating a car engine if the car were never taken out of neutral. Actually, it is even more limiting than that because at least you could rev up a car engine whereas liquid piston engines operate in a resonance, and hence single speed, mode.
