D. Decourtye et al., ANALYSIS OF VISCOUS MICROPUMPS AND MICROTURBINES, International journal of computational fluid dynamics (Print), 10(1), 1998, pp. 13-25
A numerical study of the three-dimensional viscous fluid flow in a nov
el pump/turbine device appropriate for microscale applications is perf
ormed. The device essentially consists of a rotating or free-to-rotate
cylinder eccentrically placed in a channel, and is shown to be capabl
e of generating a net flow against an externally imposed pressure grad
ient, or, conversely, generating a net torque in the presence of an ex
ternally imposed bulk flow. Full Navier-Stokes, finite-element simulat
ions are carried out to study the influence of the width and other geo
metric as well as dynamic parameters, and the results are compared to
previous two-dimensional numerical and physical experiments. The three
-dimensional simulations indicate a gradual decrease of the bulk veloc
ity and pump performance as the two side walls become closer providing
increased viscous resistance to the flow. However, effective pumping
is still observed with extremely narrow channels. The utility of the d
evice as a microturbine is also demonstrated for the first time in the
present simulations. Particularly, the angular velocity of the rotor
and the viscous torque are determined when a bulk velocity is imposed.