GasForce2

Rough approximation of gas force in a combustion engine's cylinder

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

The gas force in a cylinder of a combustion engine is computed as function of the relative distance of the two flanges. It is required that s_rel = flange_b.s - flange_a.s is in the range

0 ≤ s_rel ≤ L,

where the parameter L is the length of the cylinder. If this assumption is not fulfilled, an error occurs. The resulting approximation of the gas pressure is shown in the following figure and depends on both s_rel and the relative velocity v_rel = der(s_rel).

Parameters (5)

L	Value: Type: Length (m) Description: Length of cylinder
d	Value: Type: Length (m) Description: Diameter of cylinder
k0	Value: 0.01 Type: Volume (m³) Description: Volume V = k0 + k1*(1-x), with x = 1 - s_rel/L
k1	Value: 1 Type: Volume (m³) Description: Volume V = k0 + k1*(1-x), with x = 1 - s_rel/L
k	Value: 1 Type: HeatCapacity (J/K) Description: Gas constant (pV = kT)

Connectors (2)

	flange_a	Type: Flange_a Description: (left) driving flange (flange axis directed into cut plane, e. g. from left to right)
	flange_b	Type: Flange_b Description: (right) driven flange (flange axis directed out of cut plane)