Girish K. Jankee

Norwegian University of Science and Technology | NTNU · Department of Energy and Process Engineering

The interaction between a flow and a flexible structure can provide fascinating insight into the vortex shedding phenomenon and any propagation and mixing characteristics, which relate to a plethora of applications such as heat transfer, snoring, musical instruments, or propulsion mechanisms. In this investigation, the influence of confinement on t...

In this paper we demonstrate direct suppression of self-excited thermoacoustic instabilities over a range of operating conditions using targeted convective-acoustic interference. Premixed hydrogen enriched methane-air flames were confined in a cylindrical pipe resulting in self-excited instabilities that corresponded to the quarter wave mode of the...

The influence of a cylinder installed upstream of a round jet's exit plane on the dynamics of this flow field is investigated. Acoustic excitation is used to excite the flow at a particular frequency and phase-locked, high-resolution particle image velocimetry is employed to obtain velocity data. The cylinders have a marginal effect on the mean flo...

The ability to impart momentum while maintaining a zero net mass flux renders synthetic jet actuators attractive tools for a wide variety of applications. Implementation of a single synthetic jet actuator for large-scale operations is unrealistic and, as such, an array of actuators is usually desired during flow control processes. The added complex...

Synthetic jet actuators operate by discharging momentary slugs of fluid, which emanate from the periodic oscillations of a diaphragm. The interaction of these trains of vortices produces an unsteady jet with the ability to impart momentum to a fluid. An understanding of the behaviour of such actuators in contrasting environments is a key facet in h...

Pixel locking in stereoscopic particle image velocimetry (SPIV) is often overlooked, albeit the existence of studies demonstrating an influence on turbulent statistics. Such a bias error occurs when the seeding particles have an image diameter in the range of 1–2 pixels. Together with the advent of superior cameras and more powerful lasers, new ima...

The periodic ingestion and ejection of fluid through an orifice yield vortex rings forming an unsteady jet. The ability to impart momentum with a zero net mass flux makes synthetic jet actuators coveted components in flow control applications. Previous studies underlined the influence of geometrical parameters on synthetic jet evolution. This inves...

Peak locking in stereoscopic particle image velocimetry (S-PIV) is often overlooked, albeit the existence of studies demonstrating an influence on turbulent statistics. Peak locking occurs when the seeding particles have an image diameter in the range of 1-2 pixels. Defocusing the camera lens slightly can conveniently address the problem. However,...