Gerhard Regner

Modernizing the Opposed Piston, Two Stroke Engine for Clean, Efficient Transportation

Opposedpiston (OP) engines were once widely used i n ground and aviation applications and continue to be used today on ships. Offering both fuel efficiency and cost benefits over conventional, fourstroke engines, the OP arch itecture also features size and weight advantages. Despite these advantages, however, historical OP engines have struggled with emissions and oil consumption. Using modern technology, science and engineering, Achates Power has overcome these challenges. The result: an opposedpiston, twostroke diesel engine design that provides a ste pfunction improvement in brake thermal efficiency compared to conventional engines while meeting the most stringent, mandated emissions requirements.

Practical Applications of Opposed-Piston Engine Technology to Reduce Fuel Consumption and Emissions

Opposed-piston (OP) engines have attracted the interest of the automotive industry in recent years because of their potential for significantly improved fuel economy. Opposedpiston, two-stroke (OP2S) engine technology amplifies this fuel efficiency advantage and offers lower cost and weight due to fewer parts. While OP engines can help automotive manufacturers comply with current, and future, efficiency standards, there is still work required to prepare the engines for production. This work is mainly related to packaging and durability. At Achates Power, the OP2S technology is being developed for various applications such as commercial vehicles (heavyand medium-duty), SUVs, pick-up trucks and passenger cars (i.e. light-duty), military vehicles, large ships and stationary power (generator sets). Included in this paper is a review of the previously published OP engine efficiency advantages (thermodynamics, combustion and air system) as well as the architectures historical challenges. Also included is: 1. An overview of the packaging-related challenges of OP2S engines using opportunities with the dual-crank, Junkers Jumo-style design with power take-out options, vertical engine installation and bore-to-bore distance. 2. Different design parameters of the OP2S engine and their optimization for various applications. 3. Details of OP2S engines for various applications, including packaging concepts and performance and emissions results. These results suggest that the technology is ready to produce an economically and environmentally sustainable OP powertrain-one that is clean, fuel efficient and can fit into existing vehicles, be manufactured in todays engine plants, and run on a variety of fuels.

Optimizing combustion in an opposed-piston, two-stroke (OP2S) diesel engine

This study examines how Achates Power has developed the optimal combustion system for its OP2S engine through the: