▁processes , ▁in ▁health ▁and ▁in ▁dise ases / dis order . ▁It ▁can ▁be ▁considered ▁as ▁the ▁conj unct ure ▁of ▁mechanical ▁engineering ▁and ▁bi ological ▁engineering . ▁It ▁sp ans ▁from ▁cells ▁to ▁org ans , ▁covering ▁diverse ▁aspects ▁of ▁the ▁functionality ▁of ▁system ic ▁phys i ology , ▁including ▁card i ov asc ular , ▁resp ir atory , ▁re product ive , ▁ur inary , ▁mus cul os ke let al ▁and ▁ne uro log ical ▁systems ▁etc . ▁Bio fl uid ▁dynamics ▁and ▁its ▁simulations ▁in ▁computational ▁fluid ▁dynamics ▁( CF D ) ▁apply ▁to ▁both ▁internal ▁as ▁well ▁as ▁external ▁flows . ▁In ternal ▁flows ▁such ▁as ▁card i ov asc ular ▁blood ▁flow ▁and ▁resp ir atory ▁air flow , ▁and ▁external ▁flows ▁such ▁as ▁flying ▁and ▁aqu atic ▁lo com otion ▁( i . e ., ▁sw imming ). ▁Bi ological ▁fluid ▁Dynam ics ▁( or ▁Bio fl uid ▁Dynam ics ) ▁involves ▁the ▁study ▁of ▁the ▁motion ▁of ▁bi ological ▁flu ids ▁ ▁( e . g . ▁blood ▁flow ▁in ▁ar ter ies , ▁animal ▁flight , ▁fish ▁sw imming , ▁etc .). ▁It ▁can ▁be ▁either ▁circul atory ▁system ▁or ▁resp ir atory ▁systems . ▁Under standing ▁the ▁circul atory ▁system ▁is ▁one ▁of ▁the ▁major ▁areas ▁of ▁research . ▁The ▁resp ir atory ▁system ▁is ▁very ▁closely ▁linked ▁to ▁the ▁circul atory ▁system ▁and ▁is ▁very ▁complex ▁to ▁study ▁and ▁understand . ▁The ▁study ▁of ▁Bio fl uid ▁Dynam ics ▁is