Strategies for Complete Expansion in I.C. Engine P M V Subbarao Professor Mechanical Engineering Department Achieve Maximum Work Output….

In 2000, a new engine is born... Three cylinder 5-Stroke engine Five Stroke Internal Combustion Engine : A new concept for internal combustion engines by Gerhard Schmitz, St.Vith 2011, Belgium

The Five Stroke Cycle The five-stroke cycle consists in the following steps: 1. Admission in the high pressure (HP) cylinder 2. Compression, followed by the ignition 3. First expansion of the burned gases 4. Second expansion of the burned gases 5. Exhausting of the burned gases.

Phase A : Intake in Hp Cylinder 1, Expansion in HP 2 & Exhaust in LP

Load Pressure Regulation of the 5-stroke cycle at 4000 rpm

Speed Vs Loading Max. Torque

Phase B : Compression + Combustion in HP 1, Expansion in LP & Transfer from HP 2

Explicit Numerical Integration For a crank rotation of 

Intake Valve Lift Diagram

Work Consumed by compression Process

In above Eq., the rate of the heat loss  Q loss /dθ is expressed as: The convective heat transfer coefficient is given by the Woschni model as Modeling of Combustion Process For combustion and expansion processes: C 1 =

Dual Phase Combustion The rate of the heat input  Q gen /dθ (heat release)can be modeled using a dual Weibe function

Magnitude & Location of Peak Pressure

Phase C : Combustion + Expansion in HP 1, Intake in HP2 & Exhaust from LP

Work Delivered during Expansion in HP Cylinder

Phase D : Transfer from HP 1, Intake in HP 2 & Expansion in LP

Valve Lift Diagrams

Work Delivered during Expansion in LP Cylinder

Pressure/Volume diagram of 5-stroke cycle at 4000 rpm

BSFC of the 4- and 5-stroke engines at 4000 rpm

Net Work distribution at full load (100%) Frictional Losses : ~ 5%