Modifiers matching flow:

• standard,
• model,
• fluid,
• geophysical,
• difficult,
• turbulent,
• spatial,
• gaseous,
• environmental,
• common,
• macroscopic,
• granular,
• elementary,
• violent,
• electric,
• optic,
• multiphase,
• real,
• long,
• pedestrian,
• secondary,
• variable,
• heated,
• complex,
• industrial,
• simple,
• biological,
• internal,
• residual,
• basic,
• hydrodynamic,
• natural,
• demographic,
• simultaneous,
• hot,
• complicated,
• ecological,
• geometric,
• diverse,
• gravitational,
• open,
• financial,
• astrophysical,
• volcanic,
• shared,

Simple categories matching optic:

• system,
• device,
• flow,
• equipment,
• material,
• phenomenon,
• surface,
• crystal,
• structure,