▁the ▁previous ▁outer ▁loop . ▁ ▁Pl ug ▁the ▁new ▁newly ▁obtained ▁velocity ▁into ▁the ▁continu ity ▁equation ▁to ▁obtain ▁a ▁correction . ▁ ▁The ▁correction ▁for ▁the ▁velocity ▁that ▁is ▁obtained ▁from ▁the ▁second ▁equation ▁one ▁has ▁with ▁in com press ible ▁flow , ▁the ▁non - d iver gence ▁criter ion ▁or ▁continu ity ▁equation ▁▁▁▁ ▁is ▁computed ▁by ▁first ▁calculating ▁a ▁resid ual ▁value ▁, ▁resulting ▁from ▁sp ur ious ▁mass ▁flux , ▁then ▁using ▁this ▁mass ▁im bal ance ▁to ▁get ▁a ▁new ▁pressure ▁value . ▁The ▁pressure ▁value ▁that ▁is ▁attempted ▁to ▁compute , ▁is ▁such ▁that ▁when ▁plug ged ▁into ▁momentum ▁equations ▁a ▁diver gence - free ▁velocity ▁field ▁results . ▁The ▁mass ▁im bal ance ▁is ▁often ▁also ▁used ▁for ▁control ▁of ▁the ▁outer ▁loop . ▁The ▁name ▁of ▁this ▁class ▁of ▁methods ▁st ems ▁from ▁the ▁fact ▁that ▁the ▁correction ▁of ▁the ▁velocity ▁field ▁is ▁computed ▁through ▁the ▁pressure - field . ▁ ▁The ▁dis cret ization ▁of ▁this ▁is ▁typically ▁done ▁with ▁either ▁the ▁finite ▁element ▁method ▁or ▁the ▁finite ▁volume ▁method . ▁ ▁With ▁the ▁latter , ▁one ▁might ▁also ▁encounter ▁the ▁dual ▁mesh , ▁i . e . ▁the ▁computation ▁grid ▁obtained ▁from ▁connecting ▁the ▁cent ers ▁of ▁the ▁cells ▁that ▁the ▁initial ▁sub div ision ▁into ▁finite ▁elements ▁of ▁the ▁computation ▁domain ▁yield ed . ▁ ▁Imp licit ▁split - update ▁procedures ▁ ▁Another ▁approach ▁which ▁is ▁typically ▁used ▁in ▁F EM ▁is ▁the ▁following . ▁ ▁The ▁aim ▁of ▁the