What is a Miller cycle petrol engine?

What is a Miller cycle petrol engine?

The Miller cycle is a modification of an over-expanded cycle which provides a higher expansion ratio than compression ratio, with the advantage of providing improved thermal efficiency compared to conventional internal combustion engine operating conditions (Branyon and Simpson, 2012).

What is the difference between Otto cycle and Miller cycle?

In the traditional Otto cycle, the intake valves close at the bottom dead center (BDC), while in the Miller cycle, the intake valves closing (IVC) is advanced to ahead of the BDC making the expansion ratio larger than the compression ratio (CR) which reduces the compression work due to the advancement of intake valve …

What is a Miller and Atkinson cycle engine?

An Atkinson-cycle engine differs from a Miller-cycle engine in that the Miller-cycle engine uses some device to push air into the system – a supercharger or turbocharger – while the Atkinson-cycle engine is naturally aspirated.

What is Miller timing for NOx reduction?

Accordingly, if a strong Miller or extreme Miller timing is used to reduce NOx by 30 or 40% relative to Tier I, two-stage turbocharging (dual turbochargers) is needed because the pressure ratios of 6 or higher is required. The terminology used by Yanmar for this is “two-stage turbocharging system”.

What is a Toyota Atkinson cycle engine?

Atkinson cycle engines employ an additional linkage that will allow the air intake valve to stay open longer, creating a shorter and more complete compression stroke. This ensures that the new Tacoma 3.5-liter Atkinson cycle V-6 engine will maximize power and efficiency.

What is a late intake?

A “late intake valve closing” (LIVC) is the valve train and induction system that mimics, to some degree, what the Atkinson system was doing. LIVC is used in many, but not all, hybrid and plug-in hybrid models. LIVC is also used in conventional cars and trucks as well, but only recently.

Can you turbo an Atkinson-cycle engine?

Like said above, the Atkinson is designed to have a short compression stroke and a longer combustion stroke (by valve timing). A turbo would actually cancel out this design, meaning it would be putting more compression on the compression stroke.

What is Budack cycle?

The Budack cycle is a new version of the Atkinson engine cycle. It was created by Volkswagen to provide its vehicles with a more efficient combustion process and improved fuel efficiency. The Budack cycle also provides the driver with more power at-the-ready when they press down on the throttle.

Why is Atkinson cycle more efficient than Otto?

Compression and expansion ratios are the same in an Otto engine. Atkinson wins on efficiency because its expansion ratio is significantly larger than its compression ratio.

Why do inlet valve closes after BDC?

Intake valve closes (IVC) quite late (40°-80°after BDC), to provide more time for fresh charge to enter the cylinder, when the pressure level in the inlet pipe is higher than inside the cylinder. After BDC, the piston is no more able to suck charge.

Why is inlet valve opened before BDC?

1. Exhaust valve opens certain degrees before BDC on the power stroke, the combustion pressure has dropped considerably. Little power is lost by giving the exhaust gas this extra time to exit.

Why does exhaust valve opens before BDC?

The gases inside the cylinder posses a higher pressure even after the expansion stroke. Thus the exhaust valve is made to open before the piston reaches the BDC thus enabling the gases to escape outside on its own and the remaining gases are pushed out by the upward motion of the piston.

What is an Anderson cycle engine?

The Atkinson-cycle engine is a type of internal combustion engine invented by James Atkinson in 1882. The Atkinson cycle is designed to provide efficiency at the expense of power density. A variation of this approach is used in some modern automobile engines.