pressure — Thermodynamics

Compute the pressure due to a volume of gas.

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Interface

#include <codecogs/engineering/thermodynamics/pressure.h>

using namespace Engineering::Thermodynamics;

double pressure(double p1, double v1, double v2, double gamma=1.4)

Compute the pressure due to a change in volume of gas, based on the adiabatic expansion

$$p_1 v_1^\gamma = p_2 v_2^\gamma$$

(1)

Therefore

$$p_2 = p_1 \left(\frac{v_1}{v_2}\right)^\gamma$$

(2)

where γ is the gas constant, equal to 1.4 for air.

Example 1

The follow graph show the change pressure when an initial 2m\^3 air is expanded or contracted: \graph v1=2 p1=14.7 v2=0.1:4

Parameters

The initial pressure [psi]

The initial volume [ft\^3]

The new volume [ft\^3]

gamma

The gas constant. Default value = 1.4 (for air)

Returns

The new pressure at volume v2. [psi]

The units for pressure and volume can be interchanged with SI or Imperial systems, so long as the units used for p1 are the same as those in p2; and equally the units of v1 = v2. i.e. You are consistent.

Interactive Calculator

gamma

Result –