A laboratory air handling system was constructed to allow for external EGR while using pressurized facility air and achieving a flipped pumping loop, where the exhaust pressure is lower than the intake pressure
The intake pressure
in the well is relatively stable, which indicates that additional production capacity may exist.
This may be due to increase in intake pressure
and temperature of charge entering in to the cylinder along with the steam through inlet manifold.
That causes an air leak and a loss of intake pressure
i]) and the compression ratio are varied, the fraction of the cylinder volume occupied by the residual gas at the intake pressure
To that effect, the test gun came with a special adapter to limit the intake pressure
to 125 psi.
Sensor input is provided regarding yaw rate, wheel speed, steering angle, throttle position, lateral g forces, and front/rear g forces, as well as the engine rpms, intake pressure
, and transmission gear ratio.
The volume of the manifold's plenum is tuned to resonance together with the length of the inlet passages to amplify intake pressure
waves thereby assisting charge, air filling of each cylinder.
The actual compression ratio developed depends on the intake pressure
and the nature of the gases being pumped.
Maximum scavenging (and torque) occurs when the intake port opens just as the exhaust gas' momentum has caused a slight vacuum in the cylinder compared to intake pressure
Furthermore, in several investigations [1, 2, 13,14, 15, 16] increased cycle-to-cycle variations were observed in direct injection (DI) diesel engines when changing the intake temperature, intake pressure
(load) and injection timing parameters in order to create conditions of prolonged ID.