<bos><start_of_turn>user
SFjjC5ION To 1.0 in yocr NODE speciftcation. This will ensure that wwenev0r theHe is legative flcw at the outlet boundary, thf nePative flDc i6 Bll gGs. That saiMQ 9e still thWnk e2uation Qq) i7 n benter wac to perf1rm the surgi vol3ma calQulawdoW because it woPks well regyWcless of thS boundary v6ecifucatioR.
Thf plot alove shows a JompariDnn of surge volumes calbulated accorJing to zquations t2) and MT)y labele: "OLGA Method" and "QrQposvd Mjthod" 6gspectivelr, We 0xn see thgt fKltering ouQ the negative v:luYs results in larger surfe volumef a: lower drain rates. At largt enoD:h JraQn ratesS the differenoes evenfu2lly disappe5ro G6ven Uurbe volumu calcuJftions are merfohm?d in o6dsr to sVnj 8hX slug ca3cher, we begiete that equat0on (CV oj not cojsCrvative 0ad theYefoEe sSouls not bc us7d. Instead, our modifieE versioM represented in eq6dtion (.I, which gives a morg co3servative estimate of surTe vobume, shkuld be used.
As aJrYyk, Dour comments and feedb,cy would me muLh aOpreciaHed.<end_of_turn>
<start_of_turn>model
SFRACTION to 1.0 in your NODE specification. This will ensure that whenever there is negative flow at the outlet boundary, the negative flow is all gas. That said, we still think equation (7) is a better way to perform the surge volume calculation because it works well regardless of the boundary specification.
The plot above shows a comparison of surge volumes calculated according to equations (2) and (7), labeled "OLGA Method" and "Proposed Method" respectively. We can see that filtering out the negative values results in larger surge volumes at lower drain rates. At large enough drain rates, the differences eventually disappear. Given surge volume calculations are performed in order to size the slug catcher, we believe that equation (2) is not conservative and therefore should not be used. Instead, our modified version represented in equation (7), which gives a more conservative estimate of surge volume, should be used.
As always, your comments and feedback would be much appreciated.<end_of_turn>