NSWC/WOL TR 76-155 



The positive duration TPOS (see sketch Figure 3.1.1) was 

 calculated as described in Appendix C for the 1973 tests; for the 

 1975 tests measured values were used. The negative pressure PNEG 

 and its duration DTNEG were measured from the pressure records. 



The last five columns, Tables 3.1.1 and 3.1.2, list calculated 

 parameters for the oscillatory response of the swim bladder. The 

 number of positive cycles is the positive duration measured in 

 complete cycles of oscillation starting from the initial "at rest" 

 expansion. The number of negative cycles locates the final return to 

 ambient pressure (end of negative phase — see Figure 3.1.1) in terms 

 of the bladder oscillation. "Zero" is taken as the last expansion 

 occurring before surface cut-off. See, e.g., Figure 2.3.1. Thus, 

 unless the number of negative cycles is greater than 0.5, no final 

 expansion takes place during the negative phase. The number of 

 negative cycles, (At/T) , is a measure of the contribution of the 

 negative phase to the final bladder expansion. The relationship is 

 roughly as follows: 



(At/T) < 0.5 No contribution 



0.5 < (At/T)„_, < 1.0 Partial contribution 



NP 



1.0 £ (At/T) Full contribution 



The reader is referred to Appendix B for a more complete description, 



The bladder oscillation parameters X, Y, Z are defined as 

 follows : 



X = -100 In AMIN/A. (3.1.3) 



Y = 10 In AMAX/A. (3.1.4) 



Z = X + Y = 100 In AMAX/AMIN (3.1.5) 



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