Aerodynamic Noise: ISA Standard - Intergraph Smart Instrumentation - Reference - Hexagon

*D2 [m], P1 [Pa-a], P2 [Pa-a], W[kg/s]

*FL=FLP/Fp

1. Calculate the downstream parameters:

   

2. Calculate the following pressures:

   

3. Calculate Fd, Dj, Mj:

   

4. Now 5 regimes are possible:

   1. Regime I - P1 > P2 > P2c

   

   1. Common Calculations for Regimes II to V:

   

   1. Regime II - P2c > P2 > Pncc:

   

   1. Regime III - Pncc > P2 > P2b

      

   2. Regime IV - P2b > P2 > P2ce

      

   3. Regime V - P2ce > P2 > 0

      

5. Calculate Lpi:

   

6. Calculate TLƒo:

   

7. Calculate ƒo:

   

8. Three cases are possible when Calculating DTLfp:

   1. 

   2. 

   3. 

9. Calculate transmission loss:

   

10. Calculate Lg:

    

11. Calculate sound level