VHIM without choking

P (Pa) and specific volume i i (m /kg) to a receiving vessel at pressure P4(Pa). The effective length upstream of the valve is L (m) and the effective length downstream of the valve is Li (m). 

The methodology of Chapter 6 is applied in a fairly straightforward way in VHIM to estimate the flow as follows. First estimate the number of velocity heads, Kj, dropped over the upstream section of pipe using equation (6.58) from Section 6.6, repeated telow  

Then find the total number of velocity heads, Kr. dropped across pipe and valve from 

Assigning the number (6.43a) to equation (6.43), modified by setting Kr = 4fLID, find the critical ratio of specific volumes, (vj/ujlr /), by solving the implicit equation  

Now solve the equations listed in Section 6.4, except that the term 4 fL/D in equation (6.27) is replaced once more by AT7-, the equivalent form for velocity heads dropped  

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