The cross-sectional area of a component in a reciprocating engine, such as an intake valve or exhaust valve, is determined by the geometry of that specific component. The formula for the cross-sectional area (A) depends on the shape of the component in question.For a circular cross-sectional area, such as an intake or exhaust valve:
- A is the cross-sectional area (in square meters, m²).
- ṁ is the mass flow rate of air entering the engine (in kilograms per second, kg/s).
- ρ is the air density (in kilograms per cubic meter, kg/m³
- V is the velocity of the air entering the engine (in meters per second, m/s).