WARF: P00389US

Method and Apparatus for Simulating and Testing Internal Combustion Engines


John Moskwa, John Lahti

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing a dynamometer for a single cylinder test engine (1CTE) that allows the 1CTE to simulate a multi-cylinder engine.
OVERVIEWThe single cylinder test engine (1CTE) is an important and widely used tool in the engineering and development of internal combustion engines. The 1CTE typically consists of a single cylinder, piston and head that are representative of a multi-cylinder engine (MCE), and is used to simulate MCE performance on a smaller and simpler scale. However, 1CTEs have proven difficult to use and do not accurately represent MCE performance at low (idling) speeds – speeds of considerable interest in studies of fuel economy and emissions reduction.
THE INVENTIONUW-Madison researchers have developed a dynamometer for a single cylinder test engine (1CTE), which allows the 1CTE to simulate a multi-cylinder engine (MCE) by replicating its instantaneous engine dynamics. The dynamometer achieves this not only absorbing the torque output of the 1CTE (as in standard dynamometers), but also by delivering a motoring torque input to the 1CTE. Calculated in real-time by hardware and software-based methods, this input corresponds to the dynamic torque the 1CTE would receive from other cylinders if it were actually part of an MCE. Thus, the 1CTE acts dynamically as if interacting with other cylinders, allowing much more accurate simulation of MCE conditions over a wider range of speeds, including idling speeds.
  • Simulation of MCE during engine research and development
  • Allows use of the simple and relatively inexpensive 1CTE to simulate MCE performance in engine research
  • Could provide more accurate simulations of MCE performance than are possible with current, state-of-the-art 1CTE testing devices
  • Provides more exact simulations of MCE conditions at both low (idling) and high engine speeds
  • Because only the single-cylinder of the 1CTE is actually tested while the other cylinders of the “virtual” MCE are simulated, the configuration of the virtual MCE can be rapidly altered by changing its model.
  • 1CTE can be connected to an entire virtual power train, or other engine components, to study the effects of the dynamic coupling of these systems.
  • Dynamometer does not add significant inertia to the 1CTE, allowing studies of transient engine operation.
  • Unlike standard engine dynamometers, the dynamometer of this invention is hydraulically driven, enhancing its ability to instantaneously provide the calculated motoring torques to the 1CTE.
  • Hydraulic dynamometer allows simulation of rapidly changing speed/load conditions.
For More Information About the Inventors
Contact Information
For current licensing status, please contact Emily Bauer at or 608-960-9842.
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