Archives—April 2010

Michigan/AFRL Center of Excellence in Electric Propulsion (MACEEP) Established

Michigan Tech’s Dept of Mechanical Engineering-Engineering Mechanics under the direction of Dr. L. Brad King, is a leadership partner with the University of Michigan in the establishment of a United States Air Force (USAF) Michigan/AFRL Center of Excellence in Electric Propulsion (MECEEP).

The MACEEP is the first USAF Center of Excellence dedicated to advanced spacecraft propulsion. The MACEEP will focus on four thrust areas: Advanced Plasma Propulsion Systems for large spacecraft; Advanced Electrospray Propulsion Systems for microsats, nanosats, and picosats; Modeling and Simulation to support the advanced propulsion thrust areas; and Spacecraft Power Electronics for plasma and electrospray propulsion power processing. In addition to University of Michigan, the lead institution, and Michigan Tech, the MACEEP includes the University of California at Los Angeles, Pennsylvania State University, and Colorado State University. A $5M grant and nearly $1M of cost-sharing contributed by MACEEP partner institutions over the five-year award period, bringing the entire effort to ~$6M. Michigan Tech’s portion is $1.04 M and this is the ME-EM Department’s first involvement in a leadership role in the establishment of a national center. Professor Alec Gallimore (AERO and MIPSE Faculty) is MACEEP’s director, and Professors Iain Boyd (AERO) and Brian Gilchrist (EECS/AOSS) are MACEEP investigators and also MIPSE members.

Laser-Based Imaging of combustion Processes in Clean Diesel Engines

Thursday April 22, 2010 3:00 – 4:00 p.m.
ME-EM Building, Room 112

Mark Musculus
Sandia National Laboratories

Our nation is facing serious energy challenges resulting from our dependence on imported oil, risinggreenhouse gas concentrations in the atmosphere, and air pollution from burning fossil fuels. Tohelp meet these challenges, a better understanding of the in-cylinder processes of internalcombustion engines that create pollutant emissions at high-efficiency operation conditions isrequired. Using various laser-based optical diagnostics in an optically acessible heavy-duty dieselengine at the Combustion Research Facility of Sandia National Laboratories in Livermore, California,we are developing a new understanding of the physical and chemical processes of new clean-dieseloperating modes. This presentation will start with a broad overview of the current energy andenvironmental challenges facing our country, followed by a brief review of our currentunderstanding of conventional diesel engine technologies gained by laser-based optical diagnostics.Then, one approach to clean diesel combustion, EGR-diluted low-temperature combustion withextended premixing, will be described. One of the challenges facing this new engine operationmode is excessive unburned hydrocarbon emissions. Recent experimental work to understand thein-cylinder mechanisms responsible for the unburned fuel emissions, along with a discussion of fuelignition chemistry, will be provided. The presentation will conclude with an outlook for futureengine technologies.

Structure and Emissions of Strongly-Pulsed Turbulent Diffusion Flames in Normal- and Microgravity

Thursday April 15, 2010 3:00 – 4:00 p.m.
ME-EM Building, Room 112

James C. Hermanson
University of Washington

Many strategies have been explored for the control of flame characteristics and pollutantemissions in combustion systems. In this research strongly-pulsed, turbulent jet diffusion flameswere investigated experimentally in microgravity and in normal gravity. The fuel flow wascompletely shut off between injection pulses, resulting in the generation of compact, puff-likeflame structures. Both the cases of fixed injection velocity and fixed fuelling rate were studied.Cross-correlation of temperature measurements and high-speed imaging of the luminous flamewere used to examine the dynamic behavior of the large scale flame structures. The celerity ofthe large-scale flame structures increased markedly as the off-time between pulses was decreasedand the degree of interaction between individual flame puffs increased. The mean flame lengthwas only modestly impacted by buoyancy. Correlation with the inverse of downstream distancerevealed subtle effects of buoyancy on flame puff structure and celerity. For short injectiontimes the CO concentration substantially exceeded that of the steady (non-pulsed) flame, whilethe amount of NO was below the steady-flame level. For sufficiently short jet off-times, steadyflame levels of both CO and NO could be achieved, but in some cases with a significantly shorterflame length.

Comparison of Test and Analysis Results for the Purpose of Model Validation

Thursday April 8, 2010 3:00 – 4:00 p.m.
ME-EM Building, Room 112

James De Clerck
Department of Mechanical Engineering – Engineering Mechanics at Michigan Technological University

The accuracy of analytical models is increasingly important as prototype testing and hardware-basedproduct development are replaced by these models to identify and develop designs that meetperformance requirements. Model validation is a means to determine the predictive confidence of aparticular model or modeling process, The 6-Step Model Validation Process is a general method todetermine bias and confidence bounds for model predictions relative to test results. This process isapplied to the vibration characteristics of a sheet metal stamping as an example.

The Universities Space Research Association

Thursday April 1, 2010 3:00 – 4:00 p.m.
ME-EM Building, Room 112

Hussein Jirdeh
University Space Research Association

The seminar will introduce the Universities Space Research Association (USRA) andfocus on USRA’s engagement with member universities. USRA was incorporated in1969 in the District of Columbia as a private, nonprofit corporation under the auspices ofthe National Academy of Sciences (NAS). Institutional membership in the Associationhas grown from 49 universities when it was founded, to the current 104 institutions. Allmember institutions are PhD granting universities in the space sciences or technology.USRA is dedicated to advancing space sciences and exploration through innovativeresearch, technology, and educational programs. We accomplish this mission byproviding a collaborative membership organization where universities and other researchorganizations may cooperate effectively with each other, with the United Statesgovernment, and other entities to develop knowledge associated with space science andtechnology.An overview of USRA research institutes and programs and opportunities for graduatestudents and postdoctoral fellows will be presented.