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With the stratified-charge application, the 3.0L V-6 will continue to employ direct fuel injection, but the injectors have been redesigned to spray under higher pressure later in the intake stroke, just before compression, and the fuel is shaped to arrive in certain areas within the cylinder to optimize combustion.
Gasoline direct injection (GDI), also known as petrol direct injection (PDI), [1] is a mixture formation system for internal combustion engines that run on gasoline (petrol), where fuel is injected into the combustion chamber. This is distinct from manifold injection systems, which inject fuel into the intake manifold (inlet manifold).
Stratified charge compression ignition also relies on temperature and density increase resulting from compression. However, it injects fuel later, during the compression stroke. Combustion occurs at the boundary of the fuel and air, producing higher emissions, but allowing a leaner and higher compression burn, producing greater efficiency.
In a continuous injection system, fuel flows at all times from the fuel injectors, but at a variable flow rate. The most common automotive continuous injection system is the Bosch K-Jetronic system, introduced in 1974 and used until the mid-1990s by various car manufacturers.
Computational fluid dynamics (CFD) is a branch of fluid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid flows. Computers are used to perform the calculations required to simulate the free-stream flow of the fluid, and the interaction of the fluid ( liquids and gases ) with surfaces ...
The Volkswagen Group mainstream marques used unit injector systems (branded ”Pumpe Düse”, [14] commonly abbreviated to ”PD”) in their Suction Diesel Injection (SDI) and Turbocharged Direct Injection (TDI) diesel engines, [15] however this fuel injection method has been superseded by a common-rail design, such as the new 1.6 TDI.
[4] [5] [6] A generalized model of the flow distribution in channel networks of planar fuel cells. [6] Similar to Ohm's law, the pressure drop is assumed to be proportional to the flow rates. The relationship of pressure drop, flow rate and flow resistance is described as Q 2 = ∆P/R. f = 64/Re for laminar flow where Re is the Reynolds number.
The injection rate of DEF into the exhaust depends on the specific after-treatment system, but is typically 2–6% of diesel consumption volume. This low dosing rate ensures long fluid refill intervals and minimizes the tank's size and intrusion into vehicle packaging space.