packageExercise4DieselEngine

Information

This example package illustrates stationary-flow representations of closed-system Diesel (s, p, s, v) engine processes. Here, s denotes an isentropic process (or more general an adiabatic process with isentropic efficiency), v denotes an isochoric process (constant specific volume/density), and p denotes an isobaric process.

The examples use the SimpleAir medium model (perfect gas with constant cp) and differ with respect to the process model: PolytropicPerfectGas (systemSpec = Cycle and systemSpec = Flow) and Adiabatic.

English problem description

A four-stroke Diesel engine can be idealized using the following cycle:

• 1 → 2: Isentropic compression (T1 = 300 K, p1 = 1.00 bar, compression ratio φ = 23.0)
• 2 → 3: Isobaric heat addition (combustion, T3 = 1700 K)
• 3 → 4: Isentropic expansion (V4 = V1)
• 4 → 1: Isochoric heat rejection (in reality achieved via gas exchange of the displaced volume)

For the entire cycle, air properties can be used, assuming an ideal gas with R = 287 J/kg·K and γ = 1.40.

Contents

Name	Description
PolytropicCycle
PolytropicFlow
AdiabaticPerfectGas
BaseModel	Defines the parameters

Revisions

• 2026, by Raphael Gebhart (raphael.gebhart@dlr.de):
  Initial version.