The test appears to be the first thorough characterization of particulate emissions over the entire range of an engine's performance, relating particle size and mass to engine speed and load. CNG has the potential to become a popular alternative transportation fuel because of its domestic supply situation together with its clean burning attributes. For that to happen, however, a suitable onboard high-pressure CNG storage tank must be available. CNG storage tanks commonly used in weight-sensitive applications have either a metal or a plastic liner overwrapped with a carbon fiber composite material. The composite wrapping is designed to bear the pressure load, and the lining prevents leakage of the gas.
Composite tanks are desirable for their lightweight and resistance to corrosion and fatigue.
However, carbon fibers are expensive and do not resist impact damage well. So ORNL engineers are evaluating technologies to reduce the costs and increase the durability of fiber-reinforced composites. ORNL also recently completed a project demonstrating nondestructive evaluation techniques that could warn a vehicle operator if hazardous conditions are developing as a result of impact damage to the gas storage cylinders. Solutions to these cost and safety issues will help the United States move toward cleaner transportation and energy independence. The program is aimed at developing new, cost-effective, environmentally sound materials, and process technologies to enable the U.S. transportation industry to be more energy efficient through vehicle weight reduction.