Browse Topic: Fuels and Energy Sources

Items (36,711)
ABSTRACT State-of-the-art Diesel engines used for on-highway operation are integrated systems containing multiple subsystems for performance and emissions enhancements. The drive to lower tailpipe emissions on on-highway engines drives system complexity which is both undesired and unnecessary for military ground vehicles. There are, however, on-highway technologies such as high pressure fuel injection systems and advanced turbocharger systems that allow improving the engines’ efficiency and therefore lowering its fuel consumption. The aforementioned technologies are currently available and present possible near term opportunities for military ground vehicles. The adaptation to allow reliable operation in military vehicles will be discussed as part of this near term view. The authors will also discuss the electronic controls architecture requirements that come along with these sophisticated technologies and discuss the advantages and opportunities that present themselves using advanced
Tatur, MarekTomazic, DeanKoehler, Erik
Abstract Saft America, inc. Space and Defense Division (SDD), located in Cockeysville, Maryland, is the world leader in providing state of the art lithium ion systems for the demanding defense and space markets. Saft has been manufacturing batteries at its facility in Cockeysville for over 26 years. The major focus of the facility today is large format high power lithium ion cells and battery systems for defense applications. Saft SDD has been developing lithium ion cells and batteries since 1993. Recent efforts have focused on the industrialization of the technology for use in military hybrid vehicles. Since 2004 Saft SDD has been developing US based manufacturing capability of the entire cell and battery manufacturing processes. This effort is focused under the ManTech program with TARDEC. Overall goals of the program are aimed at improving the technology readiness to support the production of military hybrid vehicles, with areas of focus on improved performance, reliability
Ferguson, ScottNechev, KamenKelley, Dan
ABSTRACT Engine performance is traditionally measured in a dynamometer where engine speed, torque, and fuel consumption measurements can be made very accurately and environmental conditions are well controlled. Durability testing is also carried out in a dynamometer to assess reduction in engine output due to normal aging. However, the symptoms associated with incipient failures are not often studied since it requires either stressing engine components above their recommended limit or exchanging parts of known deviation with normal ones. This work describes a methodology for seeding faults in an engine by electronic means so that they can be reversibly turned on and off in a controlled fashion. The focus is on seeding faults that produce changes in engine output so that comparison between precise measurements done with laboratory instruments may be compared with estimates derived from on-board measurements. Thus, we have relied on a rather broad spectrum of measurement capabilities
Zanini, MargheritaMarko, K.James, J.Beck, Christopher S.Tom, K.Stempnik, J.
ABSTRACT This paper will address the details of realizing a silent watch solution using fuel cells while addressing the various complexities associated with their integration into a military vehicle
Mekhiche, MikeSherman, JamesMancini, Bart
ABSTRACT GenShock is an energy-harvesting, semi-active shock absorber. The device converts vertical travel of a vehicle suspension system to useful electricity. On defense platforms, this power ranges from a few hundred watts to several kilowatts. Conventional shock absorbers provide damping by dissipating suspension energy as heat, while GenShock provides damping by generating electricity. For an internal combustion engine (ICE) vehicle, the energy harvested by GenShock is used for reducing alternator load. The energy can also be conditioned for battery charging to address vehicle hotel loads. GenShock is also semi-active capable, in which each unit can stiffen or loosen in concert with the terrain, vehicle speed and load conditions for improved maneuverability. This paper presents a characterization of GenShock technology in its form and function of a direct replacement shock absorber that has regenerative and semi-active capabilities
Avadhany, Shakeel N.Anderson, Zack M.Diamond, DavidWendell, Ross
ABSTRACT AVL is developing a family of modular Auxiliary Power Units (APUs) based on the current gasoline range extender engine/generator developed by AVL for plug-in hybrid electric vehicles. These military specific variants will utilize the same basic architecture as the gasoline version while incorporating semi-direct fuel injection that is compatible with diesel fuel as well as kerosene based fuels such as F-44, JP-5, JP-8, Jet-A, etc. A systems engineering approach to the engine, generator, and power electronics modules enables a wide range of power outputs and packaging options to be easily developed from the base unit
Brakora, TonyHennessy, ChrisHunter, Gary
ABSTRACT Military ground vehicles often have service lives that exceed their original design targets. For this reason, these vehicles typically require technology upgrades during their useful life. When considering design trade-offs, both mature as well as less mature or developing technologies need to be considered against the anticipated service life for the vehicle. Early adoption of technologies that are not sufficiently mature can result in operational reliability and availability issues and increased sustainment costs. However, failure to anticipate technology refresh requirements during the original design phase may result in a platform that cannot be cost effectively upgraded as technology or functional requirements change, limiting the functionality and utility. This paper presents an Innovation Based Design (IBD) process as part of a systems engineering approach that facilitates technology refresh cycles via platform remanufacturing throughout the life of the platform. The
Thurston, MichaelHaselkorn, MichaelNasr, Nabil
Summary This paper discusses the latest techniques in vehicle modeling and simulation to support ground vehicle performance and fuel economy studies, enable system design optimization, and facilitate detailed control system design. The Autonomie software package, developed at Argonne National Laboratory, is described with emphasis on its capabilities to support Model-in-the-Loop, Software-in-the-Loop (SIL), Component-in-the-Loop (CIL), and Hardware-in-the-Loop simulations. Autonomie supports Model-Based Systems Engineering, which is growing in use as ground vehicles become more sophisticated and complex, with many more subsystems interacting within the vehicle and the environmental conditions in which the vehicles operate becoming more challenging and varied. With the advent of hybrid powertrains, the additional dimension of vehicle architecture has become one of the design variables that must be considered. This complexity results in the need for a simulation tool that is capable of
Michaels, LarryHalbach, ShaneShidore, NeerajRousseau, Aymeric
ABSTRACT VanDyne SuperTurbo Inc. has recently completed Phase I of an Army SBIR project entitled “Diesel Waste Heat Recovery Utilizing a SuperTurbocharger”. The project focused on modeling a SuperTurbocharger for a specific Army application and evaluating the potential benefits from a single device capable of supercharging, turbocharging and turbocompounding. The modeling effort resulted in predicted efficiency gains from both air flow management and mechanical waste heat recovery. Additionally, the modeling program revealed additional engine power available that was inaccessible with the engine’s current turbocharged configuration. This paper will cover the fundamentals of the technology, the Phase I engine modeling results and the path forward for the Phase II prototype testing project
VanDyne, EdWaldron, Thomas
ABSTRACT Combat vehicles have unmet needs for auxiliary power units (APUs) that reduce fuel consumption and offer improved operational effectiveness and soldier safety. Adoption of fuel cell APU technology is hindered by requirements for fuel desulfurization and reforming. Both solid-oxide and polymer-electrolyte-membrane fuel cells are poisoned by sulfur compounds in jet fuels. To more efficiently manage desulfurization processes, improved in-line methods of determining the sulfur content of fuel are required. Mainstream Engineering is developing a compact, in-line analyzer for measuring total sulfur in jet fuel for fuel cell applications. This analyzer enables less frequent desulfurizer regeneration events when compared to scheduling regenerations based on the assumed worst-case sulfur limit. The measurement technique uses multivariate analysis of Raman intensity spectra, which offers calibration robustness, contaminant detection, and identification of fuel type
Wagner, Andrew L.Yelvington, Paul E.
ABSTRACT A large number of current commercial off-the-shelf (COTS) diesel engines available to the U.S. Military employ High Pressure Common Rail (HPCR) fuel injection systems. Overall performance and endurance of these HPCR systems has the potential to vary with use of military or alternative fuels. Testing was conducted using the Ford 6.7L diesel engine to determine the impact on engine and HPCR fuel system performance with the following test fuels: diesel (ULSD), JP-8, 50%:50% volumetric blend of JP-8/Synthetic Paraffinic Kerosene (SPK), and 100% SPK. The U.S. Army 210-hr Tactical Wheeled Vehicle Cycle (TWVC) engine endurance test was used to determine engine and HPCR system performance. Engine performance over the test duration, pre- and post-test powercurves and post-test fuel injection component inspections were used to determine each fuels performance
Brandt, Adam C.Muzzell, Patsy A.Sattler, Eric R.Likos, William
ABSTRACT The electrical power demands of military ground vehicles have grown rapidly over the years. New sensors, computers, communications equipment, and weapon systems demand increased levels of electrical power to employ their capabilities. To provide our War-fighters access to these new technologies, vehicle power initiatives are keeping pace by exploring efficient integrated next-generation mobile power solutions. TARDEC’s Advanced Propulsion with Onboard Vehicle Power (APOP) program and explorations into on-platform Directed Energy based systems demonstrate an ideal coupling of compliment technologies. The advanced warfare capabilities of the future can be brought to our Warfighters through purposeful research and investment to ensure timely readiness. The TARDEC/GDLS APOP power generation effort is one such collaborative effort, and represents a potential breakthrough in next-generation power for military ground vehicles
Pesch, Kurt I.Boice, Kevin J.
ABSTRACT Cylinder Pressure Monitoring (CYPRESS™). This technology provides closed-loop feedback to enable a real-time calculation of the apparent heat release rate (AHRR). This makes it possible to adapt to the fuel ignition quality (cetane number) by adjusting the pilot injection quantity and the placement of the pilot and main injection events. This enables the engine control system to detect fuel quality and adapt the ignition sequence accordingly. This technology is also used to infer the total fuel energy injected by analyzing the AHRR, making it possible to vary the injected fuel volume quantity to achieve consistent (+/- 2%) full load power as the fuel energy density varies. Analysis of the position of AHRR with respect to the crank angle (CA) is dependent on the start of injection and subsequent fuel shots. The ability to control the position of the AHRR maintains thermal efficiency as fuel properties vary which are implemented by controlling the fuel injection pulse widths and
Jeal, GeoffHunter, Gary L.Kruit, Stephan L.
ABSTRACT In order to introduce longer heavy vehicles with multiple articulation joints between vehicle units into the UK and other European countries, rear steering of the trailing vehicle units is required to allow for sufficient manoeuvrability. An extensive program of research has been undertaken into trailer steering technologies in recent years. Such systems can enable significantly longer heavy vehicles to negotiate narrow roads. It is thought that this same technology could be used in military supply operations. Possible benefits of using multiple-trailer ‘long combination’ vehicles in military supply include: (i) Fewer vehicles are needed to perform the same supply tasks. This means fewer drivers and consequently less exposure to threats, as well as improved productivity of each driver and vehicle. (ii) Longer vehicles can have 20% to 30% lower fuel consumption for a given freight task than conventional vehicles, depending on the configuration. Application of controlled
Cebon, DavidRoebuck, RichardOdhams, Andrew
ABSTRACT Single-Fuel Concept (SFC) describes the desire to operate diesel engines using JP-8 as the only fuel in the US military due to mostly logistic reasons. However, there is a lack of a fundamental database on the combustion characteristics of JP-8 compared to those studies that have been done for diesel combustion. In this current study, several kinetic models are used to look into flame properties including ignition behavior, fuel properties including evaporation characteristics, and species evolution such as soot precursor, acetylene. Several surrogates for JP-8 fuel including tetradecane, n-dodecane and a mixture of 77 vol-% n-dodecane and 23 vol-% m-xylene are selected in the model using a detailed chemical kinetic mechanism with 330 species and 1957 reactions. Included in the model are growth mechanisms of Polycyclic Aromatic Hydrocarbon (PAH), which are known to be important for soot formation. Studies are performed to describe the fundamental combustion characteristics of
Cung, Khanh D.Johnson, Jaclyn E.Zhang, AnqiNaber, Jeffrey D.Lee, Seong-Young
ABSTRACT The need for current and future military vehicles to include more powerful and efficient powertrains is critical to both improving operational performance and reducing logistical burden. VanDyne SuperTurbo Inc. is working jointly with TARDEC and OEM partners to develop and field a revolutionary technology that simultaneously increases available engine power and reduces overall fuel consumption. The ability to incorporate efficient supercharging will allow vehicles to accelerate faster in combat situations and accept a heavier load. The ability to mechanically recover waste heat energy will allow vehicles to improve their operational range and reduce the Class III supply chain. SuperTurbo technology additionally reduces visible soot emissions and is transferable to gensets and other equipment. The end result of fielding this kind of capability will be a force protection multiplier that equips the warfighter with better performing systems
Waldron, ThomasVanDyne, EdBrown, Jared
ABSTRACT Modern medium and heavy duty Commercial Off The Shelf (COTS) diesel engines take advantage of state-of-the-art technologies to deliver excellent performance while meeting the most stringent emissions legislation. While some of these technologies offer significant advantages in terms of engine efficiency, performance and weight versus traditional military engines, others are driven purely by the need to meet emissions standards. In order to successfully adapt these COTS engines for military use and fuel (JP-8), the emissions-only systems must be removed and the engine recalibrated for maximum efficiency. The downsized, turbocharged engine would enable a simultaneous improvement in engine weight, performance and efficiency in one of the DoD’s largest fleet of vehicles - High Mobility Multipurpose Wheeled Vehicle (HMMWV), when compared to the current configuration. This paper will illustrate how a modern diesel engine was quickly developed from COTS to military-ready
Johnson, Gustav
ABSTRACT The United States Army Tank Automotive Research, Development and Engineering Center (TARDEC) is actively investigating and researching ways to advance the state of combat hybrid-electric power system technology for use in military vehicles including the Future Combat Systems’ family of manned and unmanned ground vehicles. Science Applications International Corporation (SAIC) is the lead contractor for operating the Power and Energy System Integration Laboratory (P&E SIL) in Santa Clara, CA. The P&E SIL houses a combat hybrid electric power system including a diesel engine, generator, high voltage bus, DC-DC converter, lithium ion battery pack, left and right induction motors, and left and right dynamometers. The power system is sized for a 20-22 ton tracked vehicle. The dynamometers are responsible for emulating loads that the vehicle would see while running over a course. This paper discusses the control system design for achieving mobility load emulation. Mobility load
Goodell, JarrettSmith, WilfordWong, Byron
ABSTRACT General Dynamics Land Systems has developed an Auxiliary Power Unit (APU) that provides 508A at 28VDC, for 14.2 KW. It is a stand-alone system, independent of the vehicle systems, except for utilizing vehicle fuel and vehicle batteries. Power is generated by a 570 amp alternator that is belt-driven by a diesel engine. It is load following which improves fuel efficiency and eliminates the probability of “wet stacking.” All the major components are commercially available and the APU is ready for production
Humble, Jeff
ABSTRACT Fuel Cell Systems offer high efficiency, quiet, clean, low signature power generation. To be useful for military applications they must use commonly available logistic fuels: JP8 is the primary fuel of choice. This paper reports the results of 1000 hour tests of innovative hardware to desulfurize and reform JP8. Results from early testing of a 6 kW fully integrated PEM fuel cell system operating on JP8 are also presented
George, PaulContini, VinceThornton, Doug
ABSTRACT Under support from TARDEC, an effort to develop a 10 kWe compact reliable robust power system for combat-vehicle applications is well underway. This system operates on battlefield-spec JP-8 to provide silent auxiliary power for the vehicle. The reformer converts JP-8 into a hydrogen rich reformate. The power system combines the reformer with a High-Temperature PEM (HTPEM) fuel-cell stack that retains the quick startup time of a PEM fuel-cell stack while dramatically improving the tolerance to fuel impurities to levels closer to that of SOFC stacks. The paper covers the power system development with the emphasis on the 300-hour demonstration of the 10 kWe reformer operating on JP-8 and its current integration with the fuel cell to produce the 10 kWe power system for 1000 hour demonstration and delivery to TACOM
Namazian, MehdiLux, KennethVenkataraman, GuhaElder, WilliamBhalerao, ArchanaMaslach, DanCenteck, Kevin
ABSTRACT Extensive studies have been completed for diesel engine high pressure injection on spray and combustion characteristics with diesel fuel. However the US military’s objective is to use JP-8 as a replacement to diesel fuel, which has limited spray and combustion information available. The differences between JP-8 and diesel in terms of fuel properties translate to differing spray and combustion characteristics. To fulfill the Single-Fuel Concept of the military and incorporate JP-8 fuels, knowledge of the fuels spray, vaporization, and combustion behavior is imperative for determining fuel impact on performance. This work quantifies vaporizing spray characteristics of vapor penetration and vaporizing liquid length using high speed imaging methods of combined Mie-scatter and Schlieren in a constant volume combustion vessel. Studies are undertaken at a constant injection pressure of 700 bar, at temperatures of 800, 946, and 1150 K at a density of 24.1 kg/m3. Tetradecane is used as
Johnson, Jaclyn E.Cung, Khanh D.Zhang, AnqiNaber, Jeffrey D.Lee, Seong-Young
ABSTRACT Vehicle light weighting is a priority for the U.S. Army. Due to increased survivability requirements, additional protection measures have been added to vehicles resulting in decreased fuel economy, decreased reliability and associated vehicle availability. The automotive industry response to new CAFE requirements as well as market pressures has not only created new light-weight materials and associated manufacturing technologies, but also a supply chain capable of meeting the military’ needs. This paper describes a project that is designed to test this hypothesis through the design, manufacture, and evaluation of a functional tactical demonstration vehicle with an affordable, weight optimized, multi-material substructure. The project is jointly funded by the National Automotive Center (NAC) of the United States Army, the Marine Corp, the Michigan Economic Development Corporation (MEDC), and General Dynamics Land Systems (GDLS
Gerth, Richard J.
ABSTRACT Saft America, inc. Space and Defense Division (SDD), located in Cockeysville, Maryland, is the world leader in providing state of the art Li-ion systems for the demanding defense and space markets. Recent efforts have focused on the industrialization of the technology. Since 2004 Saft SDD has been developing a higher volume manufacturing capability of the entire cell and battery manufacturing processes. This effort is focused under two ManTech programs. The Army ManTech Program with TARDEC focuses on high power batteries for use in military ground vehicles. The USAF ManTech Program with AFRL focuses on ultra high power cells for use in aviation batteries. The goals of both programs are to industrialize the high performance technology so that they are available to the military as reliable products at an affordable cost, while improving the technology. Efforts to date have yielded improvements in performance, reliability, and cost. Advances have been realized for improving the
Ferguson, ScottNechev, KamenKelley, DanGoldwasser, Elisabeth
ABSTRACT Results are presented from tests on a formulated 15W-40 mil-spec engine/transmission fluid to examine the impact of additives on improving its reliability and durability under extreme tribological conditions. A block-on-ring (BOR) configuration was used to measure the effect of five additives (an emulsion-based boric acid, tricresyl phosphate, particulate-based boron nitride, particulate-based MoS2, and particulate-based graphite) on the critical scuffing load as a function of additive concentration and time to scuff during oil-off tests (starved lubrication). A four-ball configuration was used to evaluate the impact of simulated engine grit/sand on the abrasive wear of steel as a function of grit size and loading. The results demonstrated that the additives increased the load for scuffing by 50 to 100% for the formulated oil and by 50 to 150% for the unformulated base fluid used in the formulated oil. Two of the additives (emulsion-based boric acid and tricresyl phosphate
Fenske, G. R.Ajayi, O. O.Erck, R. A.Lorenzo-Martin, C.Masoner, AshleyComfort, A. S.
ABSTRACT There is continued demand for military vehicles to provide increased fuel economy. Recent trends have appropriately turned to the development of duty cycles that better represent the real-life usage of vehicles. The advent of hybrid electric propulsion and power system architectures offer opportunities for reducing fuel consumption and greater power generation flexibility. The challenge is to effectively quantify the predicted performance for the architectures under consideration using tools that are applicable to shorter development schedules. This paper discusses the importance of using multidomain physics-based computer simulations to perform the fuel consumption analyses. The models used include mechanical, electrical, magnetic and thermal effects, and their intimate interaction in order to predict the fuel consumption for a tracked vehicle traversing courses at varying speed, up and down hills, and negotiating turns. This paper also compares the fuel consumption
Nogueiro, Porfirio L.Combs, Charles S.
ABSTRACT Under the sponsorship of TARDEC, UTRC is developing 5–10 kW Solid Oxide Fuel Cell (SOFC) Auxiliary Power Units (APU) that will be capable of operating on JP-8 with a sulfur concentration of up to the specification’s upper limit of 3000 ppmw. These APUs will be sized to fit within the relatively tight space available on U.S. Army vehicles such as the Abrams, Bradley and Stryker. The objective of the base development program that commenced in August 2010 is a 1000 hour TRL-5 demonstration of an APU in an Abrams configuration by mid-2013. This SOFC system is expected to provide power to the 28 VDC vehicle bus at a net efficiency ≥35%. In addition, the noise level is anticipated to be far below that generated by combustion engine-based APU concepts. UTRC has completed the Preliminary Design of the system and has finalized the overall system configuration and the requirements for each of the components. During the Preliminary Design phase, evaluations of the performance of sub
Tew, DavidHawkes, JustinJunker, TobyKuczek, AndrzejRheaume, JonathanSun, EllenXi, HandaYamanis, JohnZhu, TianliRatowski, JeffCenteck, Kevin
ABSTRACT The Single Common Powertrain Lubricant (SCPL) program is seeking to develop an all-season (arctic to desert), fuel-efficient, multi-functional powertrain fluid with extended drain capabilities. To evaluate candidate lubricants for the purpose of fuel consumption effects, a test cycle was developed using the GEP 6.5L(T) engine found in the HMMWV. Field data collected at Ft. Hood, TX was used to determine a set of speed, load and temperature points which could be reproduced consistently in test-cell operation. These points were condensed into a 14-mode cycle for use within the SCPL program. In addition to fresh condition oil, some lubricants were evaluated at end-of-life drain conditions to determine consumption effects over time. Results from the program indicated a significant fuel consumption benefit with lower viscosity lubricants when compared to current in-use military engine oils
Warden, RobertHansen, GregoryComfort, Allen
ABSTRACT The Hybrid Electric Vehicle Fuel Economy Methodology Study was conducted by the Automotive Instrumentation Division, US Army Aberdeen Test Center (ATC), Aberdeen Proving Ground (APG), Maryland, from June 2006 through August 2009. The program objectives were to develop a test protocol that can be used to evaluate the fuel consumption characteristics of a hybrid electric vehicle regardless of weight class, battery chemistry, and/or driveline configuration, and to characterize the performance of currently developed hybrid vehicles and tactical wheeled vehicle prototypes with regard to fuel consumption and energy usage. Eleven hybrids and eight conventional vehicles were provided for the methodology study. Fuel consumption tests were conducted on a wide spectrum of terrains ranging from level paved road surfaces to hilly cross country secondary road surfaces. Test vehicles were operated over the full range of speed capabilities on each of the terrain scenarios. Results for ground
Taylor, Wayne T.
ABSTRACT One of the main thrusts in current Army Science & Technology (S&T) activities is the development of occupant-centric vehicle structures that make the operation of the vehicle both comfortable and safe for the soldiers. Furthermore, a lighter weight vehicle structure is an enabling factor for faster transport, higher mobility, greater fuel conservation, higher payload, and a reduced ground footprint of supporting forces. Therefore, a key design challenge is to develop lightweight occupant-centric vehicle structures that can provide high levels of protection against explosive threats. In this paper, concepts for using materials, damping and other mechanisms to design structures with unique dynamic characteristics for mitigating blast loads are investigated. The Dynamic Response Index (DRI) metric [1] is employed as an occupant injury measure for determining the effectiveness of the each blast mitigation configuration that is considered. A model of the TARDEC Generic V-Hull
Jiang, WeiranVlahopoulos, NickolasCastanier, Matthew P.Thyagarajan, RaviMohammad, Syed
ABSTRACT The military has a need to source propulsion systems that have enhanced efficiencies, lower noise signatures, and improved lifetimes over existing power systems. This is true for energy storage systems on unmanned ground vehicles and for manned vehicles (i.e., Auxiliary Power Units). Fuel cells have the promise to achieve all of these goals. However, to be truly effective, these advanced systems should integrate seamlessly with the current supplies of energy storage (batteries) and energy sources (logistics fuel). The largest fuel cell development hurdle to date has been the ability to handle sulfur concentrations present in logistics fuel. Secondly, the reformer must be capable of several thousands of hours of operation utilizing logistics fuels without loss of performance due to sulfur or carbon deposition. Advancements in several key technologies have the potential to allow development of a logistics fueled solid oxide fuel cell with similar size, weight, and power
Westrich, Thomas
ABSTRACT The following paper describes the new SAPA automatic transmissions for the future military vehicles. The very high mobility requirements, the reclaim of weight, power & space and the actual relevance of the fuel consumption require a rethinking and a new vision of the automatic transmission concept and design. This is what SAPA has been working on for the last 12 years obtaining excellent technical and commercial results, a concept aimed at reducing the power losses of the conventional powershifting transmission eliminating the torque converter, reducing the spin losses -due to hydraulic pumps and friction discs-, and improving vehicle mobility on variable terrain situations as off-road
Telleria, Iñigo Garcia-Eizaga
ABSTRACT Military Ground Vehicle electric power demands continue to grow as new mission equipment is added. Using an Auxiliary Power Unit (APU) consumes less fuel than restarting the main engine frequently to charge batteries. To meet the rising demand for powerful, L-3 Combat Propulsion Systems is developing a family of heavy-fuel rotary engines. Rotary engines offer superior power density making them a good choice for applications that require high power in a limited space. Heavy fuel capability simplifies logistical challenges in the field. However, rotary engines have unique cooling challenges. Unlike a piston engine, the intake, compression, expansion, and exhaust events all take place at their respective fixed positions around the circumference of the rotor housing, leading to large temperature differences around the housing. The cooling system must be carefully developed to minimize these temperature differences in an effort to control thermal deformation, minimize thermal
Lee, KevinOehlerking, DaleRoodvoets, Levi
ABSTRACT Battelle has built multiple auxiliary power generators using liquid logistic fuels that tightly couple fuel cell and fuel processing systems, providing new control challenges. Acting as an auxiliary power supply places difficult requirements for load following and transients. Additional challenges arise from the differing time constraints of the fuel processor and fuel cell systems and the need to maintain water balance. A novel method of controlling the system has been formulated and applied, providing pushbutton start capabilities. The control system has proven to be robust and easily adaptable to system design and operating parameter changes. In addition to control concerns, the requirements for vehicle integration and desulphurization have been investigated
Thornton, DouglasContini, VinceMcCandlish, Todd
ABSTRACT Electric vehicle (EV) aggregation to provide vehicle-to-grid (V2G) services is a topic that has generated research into the economics and viability of using EVs for more than transportation, but little has been demonstrated to this point. This is especially true of using bidirectional power flows to move energy to the grid from EVs or to provide variable charge and discharge control. Our work focuses on implementing bi-directional functionality to demonstrate both V2G services and islanded microgrid support. The use of an intelligent microgrid controller combined with an EV aggregator provides new control capabilities for EV participation as energy storage devices
Massie, Darrell D.Curtiss, PeterMitchem, Sean C.
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