An enginnering collegue of mine, with little interest in F1 per se, asked me the other day about the purpose of the Air-inlet/Scoop on the cars.
I am certain this topic has been discussed on several occations here and please correct me where I'm wrong.
Anyway here goes, all based on the conventional formula for dynamic pressure, "speed sq. times density over two", where density is set to one.
Imagine that a 2500cc/1900Rpm four-stroke engine, with 100% filling of combustion chambers, would consume 380 liters (0.38 m^3) of air, in an F1 car travelling at a speed of 300 km/h (83.3 m/s). This means a need for an air intake area of 45.6 cm^2 to have the same intake-speed as said travelling speed.
The extra static pressure in the air-intake to force-fed the engine comes from the difference between travelling-speed and intake-speed. When an intake area of 200 cm^2 seems about right, it makes for a speed difference of 64.3 m/s, which creates an extra static pressure of 2.07 kPa.
Theoretically translating to some 15.7 extra horsepower if we started out with 760.
But the extra static pressure acting on the flat intake surface also creates an increase in additional air-resistance on the car. An extra static pressure of 2.07 kPa over 200 cm^2 at 64.3 m/s means a loss of 3.6 Hp.
Conclusively, a net gain of a mere 12 Hp, is the above too simplified, anyone?