76D03 Existence, uniqueness, and regularity theory [See also 35Q30, 35Q35]
76D05 Navier-Stokes equations [See also 35Q30]
76D06 Statistical solutions of Navier-Stokes and related equations [See also 60H30, 76M35]
76D07 Stokes and related (Oseen, etc.) flows 
76D08 Lubrication theory 
76D09 Viscous-inviscid interaction 
76D10 Boundary-layer theory, separation and reattachment, higher-order effects
76D17 Viscous vortex flows
76D25 Wakes and jets 
76D27 Other free-boundary flows; Hele-Shaw flows  
76D33 Waves 
76D45 Capillarity (surface tension) [See also 76B45]
76D50 Stratification effects in viscous fluids 
76D55 Flow control and optimization [See also 49Q10, 93C20, 93C95]
76D99 None of the above, but in this section