Emerging Light turbo Compound Delta-P
|New Potential Insight
into Otto's intake-cycle advantagous VVICC's under-pressure-conditions optimization
for higher specific fuel efficiency's enhancement related to taking advantage of available ambient
barometric pressure potential of normally aspirated & charged cylinder's pressure during intake
cycle of Otto cycle I.C.E.
|Otto cycle internal combustion engines, are generally classified as being of
S.I. or C.I types: for S.I. spark ignition & C.I. compression ignition
Otto cycle internal combustion engines used two major intake cycle induction charging modes that are usually referred as:
Normally Aspirated induction & Charged induction (forced-air) by means of supercharger,turbocharger or wave compressor
until recently, Prior art Otto cycle internal combustion engines mostly used only two intake cycle air-control induction strategies:
the C.A.I.C. induction strategy & the U.A.I.C. inducion strategy
(all throttled fuel control systems),including VEMB valve control systems such as:
(S.I.D.I. Spark Ignited direct fuel injection system) in stratified or homogeneous mode (gasoline GDI)
(C.I.D.I. Compression Ignited direct fuel injection system) common-rail diesel fuel (Diesel CDI)
new higher Otto cycle fuel efficiency possibilities to both Otto cycle
S.I.- C.I. CAIC & UAIC induction engines:
A mix of current- and next-generation technologies will enable automakers to go from the present combined light-duty fleet average of 27.3
mpg to 54.5 mpg in 2025, according to officials with Ricardo Inc., an engineering services and consulting company that had input on the U.
S. EPA’s CAFE rulemaking for MY2017-2025.
Ricardo’s technology roadmap for 2025 shows that vehicles powered by internal-combustion engines with three, four, or more cylinders will
use various combinations of advanced boost systems, direct injection, and advanced valvetrains to facilitate performance and boost fuel
economy, according to John Kasab, Ricardo Chief Engineer of Innovations.
“An advanced boost application could be two-stage, series-sequential turbocharging or a turbocharger-supercharger combination—depending on
the transient performance requirements. For the valvetrain, Ricardo assumes cam profile switching will be typical by 2025,” Kasab told AEI.
Mark Kuhn, Ricardo Manager of Strategic Consulting, said that automakers and suppliers have not been sitting idle prior to the 2025
mandate, with several of them already in production with advanced valvetrain designs as well as turbocharging and direct-injection
technologies as a companion to downsized engines.
While MY2016 marks the next light-duty vehicle fleet federal mandate milestone (35.5 mpg), the MY2025 timeline looms as a heady task for
Said Kasab: “The main challenge for meeting the MY2025 targets is developing a cost-effective, holistic solution for the complete vehicle
or platform that can reduce losses in the engine, transmission, driveline, and vehicle. The cost considerations are why Ricardo sees the
most interest in improving engine efficiency and in lowering vehicle mass.”