I-Corps: Controlled-Trajectory Rapid Compression and Expansion Machine

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is to enable clean energy solutions for combustion systems and renewable fuels by providing a powerful and high throughput experimental instrument for combustion and fuel characterization, especially for the transportation sector. In the U.S alone, the transportation sector, which is dominated by internal combustion engines, accounts for about 28% of total energy consumption, 70% of the total petroleum consumption and 27% of the total greenhouse emissions. The key to higher energy efficiency and lower emissions for this sector lies in a better understanding of physical and chemical characteristics of combustion processes leading to the development of advanced engines as well as alternative fuels, especially from renewable sources. The controlled trajectory rapid compression and expansion machine (CT-RCEM) addresses this pressing need of the combustion community by offering significant improvements over the conventional rapid compression machines (RCM). The CT-RCEM has the potential to transform the RCM market and bring unique benefits to end users that include universities, government research laboratories, automotive industry and oil and gas industry. This I-Corps project uses a precise motion controller with a high speed large force electrohydraulic actuator to mitigate the most fundamental limitation of the conventional RCM, an inherently rigid actuation system. The typical operation of an RCM involves, as the name suggests, rapid compression of air-fuel mixture by high speed motion of a piston in combustion chamber, leading to the ignition of the fuel. The associated data provides valuable insight into the combustion characteristics. However, the piston trajectory during this compression process is highly facility dependent and any changes in the operating parameters require hardware intervention and subsequent recalibration, leading to repeatability and reproducibility issues as well as a long turnaround time between experiments. The controlled trajectory rapid compression and expansion machine alleviates this limitation with its precisely controllable actuation system. The piston motion profile can be changed by digitally changing the piston reference trajectory assigned to the motion controller. This ability to tailor the piston trajectory allows the CT-RCEM to provide significant advantages and new capabilities over the conventional RCM. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.