Pallabazzer 



Pe Pn + ^^g Ph 1 



^g ^ ^H 



By means of the water continuity between sections (i) and (o) (where A. = A^), 

 we obtain the water acceleration as 



v„ A 



v= A„„ ° r ; • ■ (12) 



Therefore (1 + \) measures the water acceleration just due to the mixing at 

 constant section. Let us now define the pseudosonic velocity of the mixture as 



^ ^+ j_^ i/M 



o2 dp ' Ph dp 2 ' '\P^I V^H. 



_]_ _ dp _ ^ ^ I Ph 



A comparison between the orders of magnitude of the terms in the numerator 

 allows us to neglect the second one, provided that 



e >> 10"^ . 



In this case, we have -^ 



^ Pn 



(13) 



which can be accepted as valid in the range 



10"^ < e < 10-2 , (14) 



which is a practical operating range of our propulsor. By using the isentropic 

 expansion law of the gas, and the definition 



p ^ho 



Eq. (13) furnishes the following expression of the local pseudosonic velocity: 



c2 = K, -^ 



where (15) 



k Pa(l + /3ho) 



K: = 



PV. 



1116 



