IMAGINE a more quiet ride |
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ord vehicle owners may be in for a
smoother ride and increased fuel economy. Using an innovative observer
system designed by recent PhD graduate Roy Davis (left), researchers
can estimate instantaneous crankshaft torque and its ripple in an
internal combustion engine. They use this estimate to form a
disturbance input decoupling control signal, and command an electric
motor mounted on the crankshaft to generate the opposite of the ripple
torque and smooth the vehicle's vibration.
Initially Davis researched the best ways to model the engine system
that produces the torque, then produced a simplified model that could
be implemented in real time.
He also researched and modified existing observer techniques to
incorporate the effects of running the electric motor in conjunction
with the combustion engine.
A Ford Fellow for two years, Davis conducted his research both at Ford
Research Laboratory and with assistance from Professor Robert Lorenz. Currently Davis's system is being used in a hybrid vehicle
powertrain, but in the future, the crankshaft-mounted electric motors
could replace the alternator in conventional vehicles, or replace the
torque sensors in the newer, more fuel-efficient direct-injected
spark-ignited engines.
Supercomputer speeds small-engine study
A new $1.4 million high-performance supercomputer will speed up study
at the college's Engine Research Center. Installed in spring 1999, the
Origin 2000, a 32-processor computer that supplements a five-year-old
Cray Research, Inc. computer with eight processors, will increase
computational power by 16-fold and allow nearly 40 faculty, staff and
students to complete larger research projects with faster turnover.
Jay Martin, a mechanical engineering professor and ERC director, says
the Orion 2000 will enhance research for the state's small-engine
manufacturing industry. Through computer simulations, ERC researchers
can learn more about engine performance and design cleaner-running,
more fuel-efficient engines for everything from lawn mowers to boats.
The ERC purchased the supercomputer with help from a $315,000 grant
from the state Department of Commerce Technology Development Fund and
a $340,000 in-kind gift from its manufacturer, Mountain View,
Calif.-based Silicon Graphics Inc. (SGI).
New chips on the block
With $1 million in new funding over three years from the U.S. Defense
Advanced Research Projects Agency and continued funding from SEMATECH,
a 10-member consortium of semiconductor manufacturers, Professor
Roxann L. Engelstad can research advanced computer chip-making
technology in her recently established Computational Mechanics Laboratory.
Computer chips and integrated circuits are the core of every modern
electronic system, and new technology is necessary because current
optical lithography cannot create the smaller feature sizes of chips
needed to deliver more power, store more memory and perform more
tasks. Engelstad's goal is to produce features to 0.10 microns and
below.
Her group is testing alternative technologies, including lithographies
such as X-ray, 157 nm optical, projection electron beam, projection
ion beam and extreme ultraviolet. They use state-of-the-art equipment,
such as a supercomputer, to conduct simulations to determine the
accuracy and stability of the sensitive, fragile thin-film masks that
are templates for transferring patterns to computer chips. Engelstad
says the alternative technologies aren't available commercially
because of the tremendous cost to make them.
Models improve mixing in motion
Results of Professor Tim Osswald's polymer-mixing computer simulations
are so promising that manufacturers could design the screw in a
single-screw extruder to mix as efficiently as that in a twin-screw
extruder--but at one-tenth the cost.
Because of increased understanding of the physics behind the boundary
element method, a surface-modeling method that's less complicated than
finite element analysis, the computer simulations allow researchers to
model the mixing phenomena of polymer blends inside complex
three-dimensional mixing devices like extruders easily without the
cost of physically designing them. "Previously people designed mixers
by trial and error," says Osswald, who is collaborating with PhD
student Antoine Rios. Osswald likens the most efficient method of
mixing continuous-flow polymers to the stretching and folding involved
in making bread. "Current extruders deform material by shear," he
says.
Osswald's simulations may help manufacturers optimize mixing equipment
for maximal blending, controlled viscous heating, reduced residence
time and maximum throughput. In collaboration with Rauwendaal
Extrusion, Los Altos, Calif., a Madison-based company, The Madison
Group, has designed the CRD mixing section for a single-screw
extruder, which takes advantage of the dispersive mixing capability
found in a twin-screw extruder; and the dispersive/distributive static
mixer (DDSM). Patents are pending for both.
Copyright © 1999 University System Board of Regents
Content by perspective@engr.wisc.edu
Markup by webmaster@engr.wisc.edu
Date last modified: Monday, 27-Sep-1999 16:00:00 CDT
Date created: 27-Sep-1999
Annual Report 1999 Contents