Investigation of superturbocharger performance improvements through steady state engine simulation
Date
2010
Authors
Whitley, Kevin Lee, author
Olsen, Daniel B., advisor
Bradley, Thomas H., committee member
Zimmerle, Daniel John, committee member
Labadie, John W., committee member
Journal Title
Journal ISSN
Volume Title
Abstract
An integrated supercharger/turbocharger (SuperTurbo) is a device that combines the advantages of a supercharging, turbocharging and turbocompounding while eliminating some of their individual disadvantages. High boost, turbocompounding, and advanced controls are important strategies in meeting impending fuel economy requirements. High boost increases engine power output while many losses remain constant, producing an overall efficiency gain. Turbocompounding increases engine efficiency by capturing excess exhaust turbine power at high speed and torque. Supercharging increases low speed high torque operating performance. Steady state performance gains of a Superturbocharger equipped engine are investigated using engine simulation software. The engine simulation software uses a 1-D wave flow assumption to model the engine's unsteady flow behavior through one dimensional pipes. With these pipes connected to other engine components the overall performance of the engine can be modeled. GT-Power was chosen to run the simulations due to an already correlated engine model being available. This software is used to 'tune' an existing stock engine model to approximate stock engine data over the full speed and torque range. The SuperTurbo is added to the model and simulations are performed over the full engine speed and torque range for direct comparison with the stock engine. The model results show turbocompounding to be most effective at high speeds and torques in the area above 10 bar BMEP in the 3000 - 4000 RPM range and above 5 bar BMEP in the 500 - 6000 RPM range. In addition to turbocompounding there are fuel savings due to the reduced use of the compressor when it is not needed. With the stock configuration there is boost pressure created by compressor power that is then restricted by the throttle in the 2500 RPM range in the 8-12 bar BMEP range on up to 6000 RPM in the 2-10 bar BMEP range. The control of compressor speed to produce no boost at these locations improves efficiency by not wasting energy creating boost that is not needed.
Description
Rights Access
Subject
Motor vehicle -- Motors -- Superchargers
waste heat recovery
SuperTurbocharger
SuperTurbo
fuel efficiency
engine downsizing
emissions reduction
Superchargers
Automobiles -- Motors -- Superchargers
Motor vehicles -- Fuel consumption