Unsteady Flows Through Cascades : Applications to Several Flows

Unsteady Flows in Turbines

Extracting Energy from Unsteady Flows through Vortex Control

Vortex control is a new paradigm in fluid mechanics, with applications to propulsion and wake reduction. A heaving and pitching hydrofoil placed in a flow with an array of oncoming vortices can achieve a very high propulsive efficiency and reduced wake signature. The canonical example of flow with regular arrays of vortices is the Krman vortex street, and this is our model for the inflow to the...

Computation of Unsteady Nonlinear Flows in Cascades Using a Harmonic Balance Technique

A harmonic balance technique for modeling unsteady nonlinear  ows in turbomachinery is presented. The analysis exploits the fact that many unsteady  ows of interest in turbomachinery are periodic in time. Thus, the unsteady  ow conservation variables may be represented by a Fourier series in time with spatially varying coefŽ cients. This assumption leads to a harmonic balance form of the Eul...

Modeling Evaporating Droplets in Complex Unsteady Flows

In many applications, a moving fluid carries a suspension of droplets of a second phase which may change in size due to evaporation or condensation. Examples include liquid fuel drops in engines and raindrops or ice-crystals in a thunderstorm. If the number of such particles is very large, and, if further, the flow is inhomogeneous, unsteady or turbulent, it may be practically impossible to exp...

Steady and unsteady flows in collapsible channels

This paper presents a review and discussion on the numerical studies on steady and unsteady flow in collapsible channels using both the fluid-membrane model and the fluid-beam model. The aim of the research is to explore the possible mechanisms of self-excited oscillations observed in experiments on flow in collapsible tubes. The existence and stability of the steady solutions for different con...