Phenomenological Modeling of Internal Combustion Engines P M V Subbarao Professor Mechanical Engineering Department A method of inquiry based on the premise that reality consists of Processes which are Understood with consciousness ….

The First Step in Phenomenological Modeling of I.C. Engines Understand the Vehicle Driving Cycle

High Way Driving Cycle 3

Urban Driving Cycle

The SECOND step Develop Consciousness into the Engine Behaviour During a Driving Cycle

Urban Driving Cycle Vs Engine Speed

Global Phenomenological Model

Phenomenological Model for Transmission System

How to Develop a Phenomenological Model for Engine???? Is it OK to be satisfied with Otto cycle/Diesel Cycle/Dual Cycle ???? What does our consciousness say???

First Law for CV:Uniform State Uniform Flow Conservation of mass: Conservation of energy: Properties of CV are variant: Finite Duration process of Accumulation or/and depletion of mass of a CV. Finite Duration Process of Heat Addition/removal / Work across surface of CV. More Complex Energy transaction processes.

Salient Features of Process Rate of mass inflow  Rate mass outflow. The state of the mass crossing each of the areas of flow on the control surface is constant with time although the mass flow rates may be time varying. Rate of Work done is variant. Rate of Heat transfer is variant. Temporal Change of state or process is both for the CV and Flows! The incoming fluid changes its state from inlet(at one time t 0 ) to exit (at time t 0 +  t) condition. A CV with USUF process is approximates as a homogeneous but variant device. The importance of time is very high!

CV following A USUF Process for time  t A change of state of a CV as USUF device are temporal. A total change in a CV over time  t can be calculated using: Total change in mass of A CV during a time interval  t

Total change in energy of A CV during a time interval Dt All parameters mentioned above are perceived to be homogeneous and variant. Instantaneous inflow rate of Methalpy: Instantaneous outflow rate of Methalpy: Instantaneous Energy of Substance present in CV

Integral Quantities over time  t Net Heat Transfer during finite time interval Net Work Transfer during finite time interval Total Methalpy Entered the CVduring finite time interval Total Methalpy left the CV during finite time interval.

First Law for A CV executing USUF for finite cycle time

First Law Analysis: USUF Intake Process: A I R FUEL A I R SI EngineCI Engine

SI Engine CI Engine

Ideal Gas Equation for Intake Process

First Law Analysis Compression Process : USNF Transient Control Mass Fuel/Air Mixture Air SI EngineCI Engine

Compression Process

First Law Analysis: USUF Combustion Process Fuel injected at 15 o bTC SI EngineCI Engine

Combustion Process SI Engine CI Engine

First Law Analysis: USUF Power Stroke: Power Stroke

First Law Analysis: USUF Exhaust Stroke:

The Important Cycle is Executed in CM Mode