The air filter is simulated by the Control Valve module

1. 
   1 Air filter
   
2. 
   The air filter is simulated by the Control Valve module (AFT in Fig. 2(a)).
   
3. 
   The pressure drop through the air filter (∆P_{a f}) is given by the following
   
4. 
   equation [11,16].
   

∆P = ∆P_d (1)

5. 
   where, ∆P_{a f} is the pressure drop, is the mass flow rate, is the temper-
   
6. 
   ature, and P is the pressure, and subscript denotes the design condition.
   

(2)

(3)

7. 
   More text.
   
8. 
   The air filter is simulated by the Control Valve module (AFT in Fig.
   
9. 
   2(a)). The pressure drop through the air filter (∆P_{a f}) is given by the follow-
   
10. 
    ing equation [11,16].
    

∆P = ∆P_d (4)

11. 
    where, ∆P_{a f} is the pressure drop, is the mass flow rate, is the temper-
    
12. 
    ature, and P is the pressure, and subscript denotes the design condition.
    

(5)

(6)

13. 
    More text
    

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