Defense

October 12, 2012

ARL’s combustion lab sparks studies that could lead to JP-8 ‘super engine’

Contractors inspect a sample of JP8 at the Truck Fill Stand near Camp Arifjan, Kuwait, in 2010. Fuel trucks had been daily distributing millions of gallons of fuel to war fighters in the Central Command area of operations.

Studies are underway at the U.S. Army Research Laboratory, or ARL, to create a ‘super engine’ that could allow military ground vehicles, stationary power generators, and small unmanned aerial vehicles, for example, to operate with the same kind of fuel.

In the late 1980s, DOD issued its “Single Fuel Forward” policy calling for use of the kerosene-based JP-8 fuel to reduce the significant logistic burden associated with managing and transporting multiple fuels on the battlefield.

But using a single fuel exposes a host of incompatibility issues, namely in lubrication, large variation in Cetane numbers which measure the time period between the start of fuel injection and the start of engine ignition or combustion, and the fact that none of the engines that use JP-8 are designed – including their fuel systems – and calibrated for JP-8, said Chol-Bum “Mike” Kweon, acting team lead of the Engines Team of ARL’s Vehicle Technology Directorate at Aberdeen Proving Ground, Md.

He said this design gap is namely due to the fact that not enough information exists in industry and government on the specific combustion characteristics associated with JP-8′s use in intermittent combustion engines.

“Usually large companies are not willing to develop engines specific for JP-8 because it requires significant effort and funding while the market for the military is relatively small and unstable. Therefore, relatively small companies have been developing JP-8-fueled engines for Unmanned Aerial Vehicles, while diesel engines are used for ground vehicle engines. Small companies do not have the capability to perform basic fundamental research,” Kweon explained

ARL research is bridging that knowledge gap, which could eventually lead to the creation of an engine that operates optimally with JP-8.

“Fuel spray liquid penetration, quenching, vaporization, and mixing characteristics must be precisely understood to properly design combustion chambers and fuel injection systems because a fundamental understanding of fuel spray and combustion is essential in optimizing combustion processes of JP-8-fueled engines to improve fuel efficiency, engine performance and reliability,” Kweon said.

ARL’s Combustion Research Laboratory is a state-of-the-art, high-temperature and high-pressure combustion chamber that opened this summer for fuel spray and combustion research, critical areas of interest Defense-wide to facilitate the basic research and development work necessary for the successful development of JP-8-fueled combustion systems.

ARL is currently collaborating with Army Materiel Systems Analysis Activity to assess a fuel injector that is used in a Caterpillar C7 engine, used in Strykers. Results will define how fuel properties affect the performance of the fuel injection systems that are currently used in ground vehicle engines

Senior Airman Jason Reinke performs a specific gravity test on JP-8 fuel at Kirkuk Air Base in Iraq. The fuels lab provides quality control to all fuel used by local Air Force, Army, and Iraqi personnel. Airman Reinke is a fuels lab technician with the 506th Expeditionary Logistics Readiness Squadron.

 

Unique laboratory, unmatched in industry

ARL’s vehicle technology research dates back to the early 1980s in gas turbine engines, but when this research area relocated to APG in 2011 from NASA Glenn in Cleveland, Ohio, due to Base Realignment and Closure Activity, ARL broadened its vehicle technology focus to include internal combustion engines. This laboratory is accomplished with the ARL infrastructure fund that was awarded at the end of 2010.

The only combustion lab space of its kind in DoD, the Combustion Research Laboratory will also be used to facilitate the development of heavy fuel injection systems that will ultimately lead to the development of high-efficient UAV engines.

“Currently, there is no ‘robust’ heavy fuel injection system for UAV engines,” said Kweon, who received Master of Science and doctorate degrees from the University of Wisconsin-Madison (UW-Madison), which has a big engine research program in its Engine Research Center. He conducted research on diesel engines, various fuels (diesel, alternative diesel fuels, diesel fuels mixed with gasoline streams, alcohols, etc.), combustion, emissions, speciation of diesel particulate matters, optical diagnostics, etc., as degree requirements.

ARL’s combustion laboratory contains a high-temperature – up to 1,000 Kelvin (K) – and high-pressure – up to 150 bar -combustion chamber that can simulate real engine operating conditions except for fluid motion. This type of combustion chamber allows the investigation and study of uninterrupted spray and combustion processes.

“Currently, this is the only laboratory within DoD that has this capability,” Kweon emphasized.

General Motors, in Warren, Mich., has the first generation of this chamber that has a 100 bar at 1,000 K – and Caterpillar, in Peoria, Ill., has its second generation, which offers 150 bar at 1,000 K.

 

ARL has a third generation chamber

The ARL facility also has air and onsite nitrogen supply systems in which we can control oxygen concentration from zero (almost pure nitrogen) to 21 percent (pure air) in the gas mixing system. Through the high-pressure compressor, air, nitrogen, or a mixture of air and nitrogen can be supplied to the combustion chamber at pressures over 300 bar(g) to study spray only, spray and combustion, or to simulate exhaust gas recirculation, or EGR, that is common in current engines.

“However, we use only 150 bar(g) in the combustion chamber because this represents most of turbocharged internal combustion engine operating conditions. Sandia National Laboratories, N.M., and Michigan Technological University have a different type of combustion chamber (i.e., constant volume chamber) that has similar capabilities to the one at ARL in terms of temperature and pressure”.

“The main difference is that the one at ARL is a flow-through type combustion chamber that controls chamber pressure, temperature, and flowrate (very slow compared to fuel injection velocity) at set points in the test section, while the constant volume chamber has varying chamber temperature and pressure as it uses premixed combustion gases. And the injection frequency is much higher for a flow-through chamber than the constant volume chamber. Therefore, we can perform multiple injections per cycle and perform testing much faster in the flow-through chamber than in the constant volume chamber,” said Kweon, who was formerly employed at General Motors R&D in Warren, Mich., and at GM Powertrain in Pontiac, Mich., where he conducted research in cylinder pressure-based control.

For that research, Kweon and several former colleagues developed more than 21 intellectual properties. Currently, he has 30 intellectual properties that include 19 patents, seven patent applications, three patents pending, and one tool method invention.

The new laboratory will also be used to assess the performance of heavy fuel injection systems for various fuels such as JP-8, diesel, bio, and synthetic fuels; investigate the impact of various fuel properties on spray and combustion processes, ultimately on engine performance and efficiency; assess the impact of the aging of fuel injection systems on the engine performance and fuel efficiency, especially for ground vehicle engines and assess JP-8 surrogate fuels that are being formulated under the various DOD programs.

“This laboratory has a unique capability to assess the various JP-8 surrogate fuels and to compare the results with the combustion mechanisms developed by various universities and government laboratories,” said Kweon.

“This will help the scientists and researchers to develop a universal JP-8 combustion mechanism. This laboratory will be used to generate spray and combustion database that will be needed for the development and validation of computation fluid dynamics (CFD) models for engine spray and combustion processes to support the development of advanced concepts and practical designs. These CFD models will be used to optimize internal combustion engines for both UAS (unmanned aerial systems) and ground vehicles in terms of injector parameters and combustion chamber designs. These research efforts will enable UAS engines to efficiently run on heavy fuels such as JP-8.”

“The combustion research laboratory was commissioned this year and is up and running. I am confident that this laboratory will be a critical asset to the Army and DOD to support the development and/or advancement of various ground and [unmanned aerial vehicle] engines,” Kweon said.

 




All of this week's top headlines to your email every Friday.


 
 

 

Headlines April 23, 2014

News: U.S. conducts spy flights over Russia - After a tit-for-tat series of delays, the United States conducted an Open Skies Treaty intelligence flight over Russian territory April 21, a State Department official said.  Army paratroopers heading to Poland after Russian annexation of Crimea - U.S. Army paratroopers are arriving in Poland to begin a series of...
 
 

News Briefs April 23, 2014

U.S. military deaths in Afghanistan at 2,177 As of April 22, 2014, at least 2,177 members of the U.S. military had died in Afghanistan as a result of the U.S.-led invasion of Afghanistan in late 2001, according to an Associated Press count. The AP count is one less than the Defense Department’s tally. At least...
 
 

Northrop Grumman sets new greenhouse gas emission reduction goal of 30 percent by 2020

Northrop Grumman announced April 22 its commitment to reduce greenhouse gas emissions by 30 percent from 2010 levels by 2020, as part of its commemoration of Earth Day.   “Northrop Grumman is dedicated to top performance in environmental sustainability,” said Wes Bush, chairman, chief executive officer and president. “This new goal sets the bar significantly...
 

 

Lockheed Martin demonstrates enhanced ground control system, software for small UAV

Lockheed Martin’s Group 1 family of unmanned aircraft systems is migrating to enhanced automation capabilities using its Kestrelô “Fly Light” flight control systems and industry-leading mobile Ground Control Station software. The increased automation allows operators to focus on executing the mission, rather than flying various aircraft. Earlier this year, Lockheed MartinR...
 
 

U.S. Navy awards General Dynamics $33 million to operate, maintain military sealift ships

The U.S. Navy has awarded General Dynamics American Overseas Marine LLC a $32.7 million contract modification to operate and maintain seven large, medium-speed, roll-on / roll-off ships for the Military Sealift Command. AMSEA is a wholly owned subsidiary of General Dynamics. Under the terms of the modification, AMSEA will provide services including crewing, engineering, maintenance,...
 
 

US Navy deploys Standard Missile-3 Block IB for first time

In partnership with the Missile Defense Agency, the U.S. Navy deployed the second-generation Standard Missile-3 Block IB made by Raytheon for the first time, initiating the second phase of the Phased Adaptive Approach. “The SM-3 Block IB’s completion of initial operational testing last year set the stage for a rapid deployment to theater,” said Dr....
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>