A team of researchers from Colorado State University’s Energy Institute has received a $1.2-million grant from the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy to look at making natural gas engines as efficient as diesel engines in the same class. (Earlier post.)

Specifically, the researchers will develop medium- and heavy-duty, on-road natural gas engines that are as efficient as traditional diesel engines often used in long-haul 18-wheeler trucks, garbage trucks and delivery trucks.

The Colorado State team is working with commercial partners Cummins Inc. and Woodward, Inc. to tackle this engine technology challenge. The team includes Associate Professor Daniel Olsen; Assistant Professor Bret Windom; and Professor Anthony Marchese, all in the Department of Mechanical Engineering.

Cummins and Woodward, having worked on these problems for decades, will provide the team with practical hardware for testing and the capability to commercialize technology breakthroughs. Cummins is building a single-cylinder, 2.5-liter natural gas engine to be used as a key research tool for the project. Woodward is contributing combustion, ignition, fuel delivery technology and advanced engine controls.

The Energy Institute team is proposing to break down technological barriers such as the knock and misfire limits to optimize combustion and improve natural gas engine efficiency.

The team plans to do this using a three-pronged approach. First, they will use a laser spark-ignited rapid compression machine (RCM), an experimental device that simulates a single compression stroke of an internal combustion engine, to study the chemical kinetics and combustion of natural gas.

Second, they will use a Cooperative Fuel Research (CFR) engine to study how gas composition impacts end gas auto-ignition, the phenomenon that leads to engine knock.

Third, using lessons learned from the RCM and CFR engine studies, the team will develop engine models to direct the design of the combustion-related components in a specially built Cummins engine for final testing and system optimization. Woodward’s advanced combustion, fuel delivery and state-of-the-art combustion control technology will also play a role. These contributions will enable sustained operation of controlled auto-ignition, minimizing knock margin conservatism.

The CSU [rapid compression machine] is a unique device to test the auto-ignition characteristics of the wide range of components found in natural gas and is able to simulate the components of recirculated exhaust gas for knock suppression. This level of research in a wide range of fuels has not been done before, and it will help with engine design and control.

—CSU associate professor Gregory Hampson, Woodward’s sponsor on this project

The team is set to begin work on the three-year project this summer.