A Renewable-Fuel 60% Efficient Engine - Insights from the General Cycle Equation
SAE-PP-00370
11/25/2023
- Content
- The General Cycle is a thermodynamic cycle that includes all six steps common to engine cycles. Thus it includes other engine cycles as subsets, each of these lacking one or more of the steps. The General Cycle engine, outside the realm of more commonly known thermodynamic cycles, is best suited to attain highest efficiency. Essential strategies for attaining 60% efficiency in an internal combustion engine are: (1) optimize parameters in the General Cycle, (2) reduce friction and heat transfer losses, and (3) preserve combustion efficiency. Obtaining a practical 60% efficient engine is a struggle against engine cost and power density. Add to that the problem of using only a renewable fuel with the intent of satisfying three additional goals: (1) net-zero-carbon emissions, (2) compatible with existing infrastructure and fuel systems, and (3) able to replace all current fossil fuel use. These conditions will require the highest efficiency in order to satisfy market demand given a limited supply of sustainable fuel. The result is a plan for a 60% efficient engine with practically no emissions. Does applying all of these steps provide a vision for the internal combustion engine of the future? This is not an idle question—decision makers should discard the idea to “electrify everything.” Batteries have far less energy density than do fuels, and they have other problems, such as refueling logistics, when used in working machines such as trucks, farm machinery, and earth movers. Modern civilization was built by internal combustion engines. The world will continue to use engines far into the future, and they can be designed to operate sustainably.
- Citation
- Rogers, E., and Collett, G., "A Renewable-Fuel 60% Efficient Engine - Insights from the General Cycle Equation," SAE MobilityRxiv™ Preprint, submitted November 25, 2023, https://doi.org/10.47953/SAE-PP-00370.