Mechanical engineering graduate student Brandon Dawson examines an engine used in the department’s research efforts in engine controls and optimization.

What can be done to reduce oil consumption in automobiles?

With gas prices regularly topping $3.00 per gallon around the country, fuel efficiency is getting significant attention from federal agencies and automobile companies. One path to greater fuel efficiency is lean-burn engines, which are internal combustion engines regulated to run on a lower fuel-to-air ratio than standard engines and promise to increase fuel efficiency by up to 20% without sacrificing performance.

Building these engines is one of the targets of the interdisciplinary engine research conducted at the UH Cullen College of Engineering.

Matthew Franchek Professor and Chair of Mechanical Engineering

This work can be applied to far more than lean-burn engines, noted Matthew Franchek, professor and chair of the college’s mechanical engineering department. By providing and unifying mathematical models of engines, exhaust treatment systems and engine diagnostics and control systems, Cullen College enables automobile companies and engine manufacturers to more easily design vehicles with various combinations of power, fuel efficiency and reduced emissions. These efforts at Cullen College are significant enough that they are supported by grants from Ford, General Motors, Cummins Diesel, the Army Research Center and the National Science Foundation.

“This is about systems integration and optimization from a systems engineering point of view,” said Franchek. “We’re providing these companies the tools to create engines with the characteristics
they want.”

In the case of lean-burn engines, a large chunk of the effort involves modeling various aspects of lean-burn engines and catalyst systems. Franchek focuses primarily on providing mathematical models of how lean-burn engines should behave under different driving conditions and with slightly different ratios of fuel and oxygen.

Researchers in the Department of Chemical and Biomolecular Engineering model and optimize the design of catalysts for reducing the emissions of lean-burn engines. The catalysts used in standard engines rely on a specific fuel-to-air ratio to effectively reduce nitric oxides, or NOx, a precursor to ozone. Since lean-burn engines operate on a lower ratio, those techniques are less effective at NOx removal. Researchers, therefore, conduct extensive work in NOx reduction that includes catalyst modeling and testing of a separate engine component called a lean NOx trap.

These engine and catalyst models are then applied to engines that are tested under simulated real-world driving conditions. During these tests, there are dozens of different factors that are monitored and regulated to determine the validity of these models.

Karolos Grigoriadis Professor of Mechanical Engineering

The data from these tests are then used to create another key component of engines—adaptive controllers for engine regulation and fuel/air ratio control. Mechanical Engineering Professor Karolos Grigoriadis and Franchek are developing complex algorithms that will allow an engine CPU receiving information from various engine sensors to adjust and optimize engine behavior for peak performance and minimal emissions.

Ultimately, Grigoriadis sees these efforts finding their way into commercial use within the next few years. “Engine manufacturers pay attention to even small increases in cost,” he said, “but environmental regulations and fuels prices will soon push these technologies into production.”

Recoverable Resources
• How much oil is still left in the ground?
• How can we lower the cost of retrieving oil?
• How can we improve the process of oil production?
• What role will petroleum play in an alternative energy future?

Cleaner Consumption
• What can be done to reduce oil consumption in automobiles?
• Are plant-based fuels a realistic solution to our energy demands?
• What is currently being done to improve the air quality in Houston?

Going Green
• What might eventually replace oil and gas in the future?
• What about wind?
• Can we really leverage the moon… for energy?