RCAIDE.Library.Methods.Aeroacoustics.Semi_Empirical.Turbofan.ground_proximity_effect.ground_proximity_effect#

ground_proximity_effect(Velocity_mixed, sound_ambient, theta_m, engine_height, Diameter_mixed, frequency)[source]#

This function calculates the ground proximity effect, in decibels, for full-scale engine test stands.

Parameters:

  • Velocity_mixed (float) – Velocity of the mixed jet [m/s].

  • sound_ambient (float) – Ambient sound level [SPL].

  • theta_m (float) – Angle for the mixed jet [rad].

  • engine_height (float) – Height of the engine above the ground [m].

  • Diameter_mixed (float) – Diameter of the mixed jet [m].

  • frequency (float) – Frequency of the sound wave [1/s].

Returns:

GPROX_m – Ground proximity effect adjustment for the mixed jet [dB].

Return type:

float

Notes

The function assumes that the ground proximity effect is significant for the mixed jet component and calculates the noise adjustments accordingly.

Definitions

‘GPROX_m’

Ground Proximity Effect, the adjustment in decibels due to the proximity of the ground.

References

[1] SAE ARP876D: Gas Turbine Jet Exhaust Noise Prediction (original) [2] de Almeida, Odenir. “Semi-empirical methods for coaxial jet noise prediction.” (2008). (adapted)