[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
Libertine FPE builds demo prototype of linear free piston generator
April 17, 2015
UK-based Libertine FPE has built a demonstration prototype of its linear electrical machine for what it is calling “Digital Piston Motion Control” in free piston engine applications. (Earlier post.) This technology will allow researchers to develop future combustion engines free from the piston motion constraints dictated by the crankshaft. Already validated at proof-of-concept level, Libertine’s new hardware uses production-feasible component designs suitable for automotive hybrid powertrain modules, such as range extenders.
Unlike conventional engine-generator combinations which use a crankshaft and mechanical powertrain to rotate an electrical machine, Libertine’s technology uses a linear electrical machine to generate power directly from the piston’s motion. The linear generator can also be used as a motor to apply a variable force to the piston, and this approach permits each piston’s velocity, motion profile and compression and expansion ratio to be optimally controlled via the ECU to accommodate startup, transient and flex-fuel operation. This flexibility offers significant improvements in combustion efficiency and has the potential to produce a third more power from the same fuel input.
DOE to award $55.8M for advanced vehicle technologies; $35M for fuel cell and hydrogen
January 22, 2015
US Energy Secretary Ernest Moniz announced a new Vehicle Technologie program-wide funding opportunity (DE-FOA-0001201) for $55.8 million. DOE also announced up to $35 million to advance fuel cell and hydrogen technologies, including enabling the early adoption of fuel cell applications, such as light duty fuel cell electric vehicles. This new funding opportunity announcement will be available in early February.
The Vehicle Technologies funding is targeted at a wide range of research, development, and demonstration projects that aim to reduce the price and improve the efficiency of plug-in electric, alternative fuel, and conventional vehicles. Topics addressed include: advanced batteries (including manufacturing processes) and electric drive R&D; Lightweight materials; Advanced combustion engine and enabling technologies R&D; and Fuels technologies (dedicated or dual-fuel natural gas engine technologies).
Start-up Eco-Motive developing dual-fuel “H” engine; parallel, independently fueled piston banks
December 01, 2014
|The H-engine—basically two separate engines housed within the same engine block—comprises two switchable parallel piston banks, independently fueled by gasoline and CNG. Click to enlarge.|
Startup Eco-Motive has developed what it calls the first dual-fuel “H” engine; it recently received a patent (#8807098) on the design. The H-shaped engine comprises parallel left-side and right-side vertical inline piston banks, each having a crankshaft and pistons, a cylinder head, and individual fuel feeds, but sharing a common power transmission system. Each piston bank operates independently of the other but is housed within the same engine block and has separate lubrication systems.
The Eco-Motive H-motor—basically two separate engines housed within the same engine block—can be powered by either gasoline or compressed natural gas (CNG), at the driver’s decision. The chosen engine is mechanically or electrically selected via an engine bank selector box using a selector control which selects the fuel type and engages a drive gear on the crankshaft of the selected engine, and transfers power to the transmission. The selector control actuates a transfer system that prevents simultaneous operation of both engines. The vehicle stays in that fuel mode until changed by the driver.
Motiv Engines introduces 2nd-generation split-cycle concept; MkII Clarke-Brayton heavy-duty engine being designed for LNG
May 08, 2014
|Section of the MkII Clarke-Brayton split-cycle engine. Note the three different cylinder sizes. Air moves sequentially from induction (top cylinder) to combustion (middle cylinder) to expansion (bottom cylinder). Click to enlarge.|
Motiv Engines, LLC introduced the second-generation of its engine concept dubbed the MkII Clarke-Brayton Engine, which it intends to develop into a heavy-duty on-highway engine fueled by liquid natural gas (LNG). The prototype is fueled by diesel, a first step in proving the technology before developing a new LNG fuel system.
The MkII Clarke-Brayton Engine is a boxer-configuration split-cycle engine implementing what Motiv calls the Clarke-Brayton cycle. The thermodynamics of the engine are virtually identical to the company’s previous CCI (Compact Compression Ignition) design, as described in a 2013 SAE paper, but are implemented in a much more conventional way.