Project: Optimizing combustion parameters for highly efficient engines
Student: PhD
Sponsor: DOE
Prof. Rolf Reitz
To achieve high engine efficiency while maintaining low pollutant emissions,
unconventional low-temperature combustion strategies including the use of dual fuels are
being explored. In this project multi-dimensional CFD models will be used together with
efficient optimization methods to recommend combustion chamber geometries for
improved compression ignition engines. New models that consider interactions between
flows, alternative fuels and combustion will also be assessed and validated using
available experimental measurements of spray, combustion, and pollutant formation.
------------------------------------------------Project: Develop and implement advanced spray models for future high efficiency
engines
Student: PhD
Sponsor: General Motors
Prof. Rolf Reitz
The objective of this project is to improve fuel injection and spray models for diesel and
gasoline engines. This task will develop and implement spray models that account for
advanced nozzle designs and improved spray and vaporization models for realistic fuels.
The use of multiple injections, injector nozzles with many small holes, rate-shape effects,
and effects of wall-films on in-cylinder flows, combustion and emissions will be
considered.
------------------------------------------------Project: UREA-After-treatment Computational Modeling [Filled]
Student: PhD
Sponsor: DoE
Prof. Mario F. Trujillo
The injection of aqueous urea has proven an effective means of treating exhaust gases
with the objective of reducing NOx pollutant concentrations and thus limiting the
environmental damage. There are various aspects of this process that remain largely
unknown and others that can be substantially improved. For instance, from the chemistry
side, the transformation of aqueous UREA into gaseous ammonia and iso-cyanic acid
involves the precipitation of urea and its potential concurrent phase change. This process
is still largely unknown. From the mixing point of view, the role of turbulent scales in the
effective transport of ammonia could be enhanced, directly improving this after-treatment
process. Aspects, such as these, are currently targeted for investigation under this
ongoing project. A new graduate student is sought that will help contribute to
computational research in this area.
-------------------------------------------------
Project: Fuel Neutral Particulate Study
Student: MS or Ph.D.
Sponsor: GM
Prof. Dave Foster
New regulations on the total particle number that may be emitted from a vehicle will go
into effect soon. Gasoline engines, which have no difficulty meeting a mass based
regulation, will be challenged to meet the particle number standard. This is especially
true for direct injection gasoline engines, which will be used extensively to meet the new
fuel economy standards. In this work a gasoline direct injection engine will be run under
different conditions, with different fuels, and measurements of the particulate number and
size distribution leaving the engine, as well as other emissions, will be made. The
objective of the research is to assess the particle size and number distribution for a range
of operating conditions and develop an understanding of the phenomena responsible for
their formation in-cylinder. The research is already underway and this project is a
continuation of the program. The engine and instrumentation already exist in the
laboratory. The particulate emission from the engine is very sensitive to minor variations
in engine operation and measurement of the particulate requires very specific well
controlled sampling protocols.
------------------------------------------------Project: Fuel Composition, Combustion Mode and Engine Type Effects on
Particulate Characteristics Low Temperature Combustion in a Single Cylinder
Research Engine
Student: MS or Ph.D.
Sponsor: GM
Prof. Dave Foster
The number of particulates emitted from engines will be regulated on European vehicles
and is proposed for regulation on US vehicles. Combustion and engine technologies that
will be implemented to reduce fuel consumption, such as diesel engines, direct injection
spark ignition engines along with the use of low temperature combustion will be
challenged to meet the proposed particulate number regulations.
The focus of this project will be to make detailed measurements of the number and size
distribution as well as the physical and chemical characterizations of the particulate
matter emitted from different engines operating with different fuels. This will be
accomplished by augmenting the data taking for two on going projects. In one project we
are exploring the LTC operation of a direct injection compression ignition engine with a
range of fuels (gasoline-like to diesel-like, including bio-diesel). In the other project we
are evaluating the particulate number emission for a gasoline direction injection engine.
The objective of this research project will be to make particulate number and
compositional measurement for these different engines and evaluate the similarities and
differences in the emitted particulate for these different engines, operating in different
combustion modes for a range of fuels. These data will be interpreted in terms of its
implications for meeting number based particulate standards and approaches that may be
pursued to reduce the number of particles emitted from the cylinder.
------------------------------------------------Project: The Study of LTC and Combustion Mode Switching During Engine
Transients
Student: MS
Sponsor: DOE
Prof. Dave Foster
Low temperature combustion (LTC) is being studied extensively on single cylinder
research engines operating under steady state conditions. When these combustion
regimes are integrated into production, it will be necessary to operate in a multi-cylinder
engine. Furthermore, the engine will be operating over transient cycles and it will be
necessary to switch between conventional combustion and LTC and back. Studying the
behavior of a multi-cylinder engine operating in LTC mode, and undergoing transients
and/or combustion mode changes is the focus of this study. The multi-cylinder engine
being used in this research has low-pressure and high-pressure EGR loops, a variable
geometry turbocharger and a flexible common rail injection system. Successful transient
operation of the multi-cylinder engine during combustion mode switches, or during
transient LTC operation, will require a fundamental understanding of the impact of the
time responses of the engine’s air handling, fuel injection and EGR systems and how they
interact collectively with LTC operation or combustion mode change. This project is
currently underway and supports two students. One of the students is graduating. This
position will replace that student.
------------------------------------------------Project: Fundamental Investigation of Soot Formation in High-Pressure Flames
with Real Liquid Fuels
Student: MS or PhD
Sponsor: ACS
Prof. Dave Rothamer
Soot is an important criterion pollutant species emitted by modern internal combustions
engines. Most fundamental data on soot formation in flames is available only for
atmospheric pressure conditions which are not representative of conditions in practical
power generation devices (piston IC engines, gas turbines, etc.). Additionally, most data
is for simple gaseous fuels, whereas most practical devices use liquid fuels derived from
petroleum. To obtained measurements at relevant conditions a high pressure burner
facility capable of operation on vaporized liquid fuels will be designed and built. The
facility will be used to characterize the dependence of soot formation at high pressures on
fuel chemical structure through the application of advanced laser diagnostics.
-------------------------------------------------
Project: Knock Detection and Characterization in an SI Engine
Student: MS or PhD
Sponsor: Mercury
Prof. Jaal Ghandhi
Knock is the critical limiting factor of spark-ignition engine performance. This project
aims to understand the causes and characterization of knock based on experimental
measurements. A three-cylinder outboard marine engine that has been installed and
instrumented in our laboratory for this purpose. There are two thrust areas of this project.
First, an extensive survey of knock detection strategies will be performed using the
measured cylinder pressure. This will be focused on developing a statistically converged
description of the knocking process. The second thrust area will be the development of a
system that can rapidly identify the knock intensity using pressure, ion or acceleration
sensing. The goal for this system is to prevent engine damage during calibration in an
automated test cell.
-------------------------------------------------
Project: In-cylinder Investigation of Engine Size-Scaling Phenomena [Filled]
Student: PhD
Sponsor: Wisconsin Small Engine Consortium
Prof. Jaal Ghandhi
Two optical engines that are geometrically similar, with a length scale ratio of 1.7:1, have
been built to study the effect of engine size scaling on the turbulent flowfield of an engine.
Testing is currently underway to measure the velocity field using particle image
velocimetry (PIV) and the scalar mixing field using planar laser-induced fluorescence.
The operating conditions necessary to get similar behavior are being investigated under
motored engine operation. In this project, further measurements will be made of the
motoring flowfield, and the engines will also be fired to allow a comparison of the
combustion performance and flame topography, both of which depend on the underlying
turbulent flowfield.
-------------------------------------------------