Design Parameters for Small Engines Based on Market Research 2018-01-1717

Small internal combustion engines outperform batteries and fuel cells in regards to weight for a range of applications, including consumer products, marine vehicles, small manned ground vehicles, unmanned vehicles, and generators. The power ranges for these applications are typically between 1 kW and 10 kW. There are numerous technical challenges associated with engines producing power in this range resulting in low power density and high specific fuel consumption. As such, there is a large range of engine design solutions that are commercially available in this power range to overcome these technical challenges. A market survey was conducted of commercially available engines with power outputs less than 10 kW. The subsequent analysis highlights the trade-offs between power output, engine weight, and specific fuel consumption. These engines are analyzed to show the benefits and disadvantages of different engine design parameters including fuel type, number of strokes per cycle, number of cylinders, intake pressure, and cooling strategy. A Pareto frontier analysis is conducted to identify the top performing engines based on the output power and the total power system weight. Recommended designs are presented for different ranges of output powers.