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Topic Name: Mechanical engineer develops laser technologies to analyze combustion system, biofuels
Category: BioFuels
Research persons: Terry Meyer
Location: Iowa State University, United States
Details
Let's say a fuel derived from biomass
produces too much soot when it's burned in a combustion chamber designed for
fossil fuels.
How can an engineer find the source of the problem? It originates, after all,
in the flame zone of a highly turbulent combustion chamber. That's not exactly
an easy place for an engineer to take measurements.
"It's fairly obvious when a combustor is not running well and producing
a lot of soot and other pollutants," said Terry
Meyer, an assistant professor of mechanical engineering at Iowa
State University. "But then how do you solve that problem? To do that
we can open up the black box and look inside the combustion chamber
itself."
The tools that Meyer is developing to do that are highly sophisticated
laser-based sensors that can capture images at thousands and even millions of
frames per second. Those images record all kinds of data about what's happening
in the flaming mix of fuel and air.
"The goal is to probe this harsh environment to provide the knowledge
required to reduce pollutant emissions and enable the utilization of alternative
fuels," Meyer said.
By selecting lasers of different wavelengths, Meyer's combustion sensors can
record where pollutants such as soot, nitric oxide and carbon monoxide are being
formed. The sensors can also look for unburned fuel and capture data about fuel
sprays, fuel-air mixing and energy release.
Meyer's lab is now working on a two-year project to develop and advance laser
techniques that are expected to help engineers improve the combustion systems
that move vehicles, produce power and heat buildings. An important goal of the
project is to analyze and improve the performance of alternative fuels in modern
combustion systems.
Meyer's research is supported by an $87,000 grant from the Grow Iowa Values
Fund, a state economic development program. This grant is supplemented by a
contribution of products and engineering expertise from Goodrich Corporation's
Engine Components unit in West Des Moines, a producer of fuel system components
for aircraft engines, auxiliary power units, power-generating turbines and home
heating systems. ConocoPhillips, the third largest integrated energy company in
the United States, is supporting similar projects in Meyer's lab. The projects
are part of ConocoPhillips' eight-year, $22.5 million research program at Iowa
State. Meyer's research is also drawing interest and support from sources such
at the National Aeronautics and Space Administration and the U.S. Air Force.
Meyer started working with laser diagnostics when he was a doctoral student
in mechanical engineering at the University of Illinois at Urbana-Champaign. The
work continued when he spent six years as a scientist developing and applying
laser techniques for the Air Force Research Laboratory at Wright-Patterson Air
Force Base in Dayton, Ohio.
He made the move to Iowa State in 2006 and is working to apply some of the
military's sophisticated laser technologies to civilian applications.
And so Meyer's system of high-speed lasers, frequency conversion units,
mirrors and cameras is being built in his Multiphase Reacting Flow Laboratory on
the ground floor of Iowa State's Black Engineering Building.
It's work that could have impacts far beyond his lab. Meyer said his research
aims to reduce reliance on fossil fuels, which currently account for 85 percent
of the world's energy use.
Note for Fossil fuel
Fossil fuels or mineral fuels are fossil source fuels, this is, hydrocarbons found within the top layer of the earth’s crust.
They range from very volatile materials with low carbon:hydrogen ratios like methane, to liquid petroleum to nonvolatile materials composed of almost pure carbon, like anthracite coal. It is generally accepted that they formed from the fossilized remains of dead plants and
animals by exposure to heat and pressure in the Earth's crust over hundreds of millions of
years. This is known as the biogenic theory and was first introduced by Mikhail Lomonosov in 1757. There is an opposing theory that the more volatile hydrocarbons, especially natural gas, are formed by abiogenic processes, that is no living material was involved in their formation.
It was estimated by the Energy Information Administration that in 2005 86% of primary energy production in the world came from burning fossil fuels. With the remaining Non-fossil being hydro 6.3%, nuclear 6.0%, and other (geothermal, solar, wind, and wood and waste) 0.9
percent.
Fossil fuels are non-renewable resources because they take millions of years to form and reserves are being depleted much faster than new ones are being formed. Concern about fossil fuel supplies is one of the causes of regional and global conflicts. The production and use of fossil fuels raise environmental concerns. A global movement toward the generation of renewable energy is therefore under way to help meet increased energy needs.
Note for Combustion chamber
A combustion chamber is the part of an engine in which fuel is burned.
Internal Combustion Engine
The leftover hot gases produced by this combustion tend to occupy a far greater volume than the original fuel, thus creating an increase in pressure within the limited volume of the chamber. This pressure can be used to do work, for example, to move a piston on a crankshaft. The energy can be converted to various types of motion or to produce thrust when directed out of a nozzle as in a rocket or jet engine.
Petrol or Gasoline engine
A reciprocating engine is often designed so that the moving pistons are flush with the top of the cylinder block at top dead centre. The combustion chamber is recessed in the cylinder head and commonly contains a single intake valve and a single exhaust valve. Some engines use a dished piston and in this case the combustion chamber can be considered as partly within the cylinder. Various shapes of combustion chamber have been used, such as L-head (or flathead) for side-valve engines;"bathtub", "hemispherical" and "wedge" for overhead valve engines; and "pent-roof" for engines having 3, 4 or 5 valves per cylinder. The shape of the chamber has a marked effect on power output, efficiency and harmful emissions; the designer's objectives are to burn all of the mixture as completely as possible while avoiding excessive temperatures (which create NOx). This is best achieved with a compact rather than elongated chamber.
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