Active Combustion Control Using a Fluidic Oscillator for Asymmetric Fuel Flow Modulation

Numerical Modeling and Validation of the Flow in a Fluidic Oscillator

“…Hence, we assume the baseline case to be independent of the grid resolution, which will therefore be used for the following investigations. Since Guyot et al 24 observed in their test an influence of the discrete outlets conditions on the global oscillating behavior, it seemed to be important to check if the outlet boundary conditions affect the oscillating characteristics. Therefore, the baseline case was extended by a square domain allowing for an unconfined outlet flow.…”

“…All meshes were refined where high velocity gradients were expected as it was observed in the experiments. 20 Guyot et al 24 encountered in tests with a fluidic oscillator in a model combustion test rig that by adding tubes to the discrete outlets the oscillation is affected. To specify the influence of the outlet geometry, the baseline case was extended by a rectangular domain, as shown in employing the unsteady Shear Stress Transport model by Menter 25 because it is known to be a good compromise between numerical accuracy and computational cost.…”

“…The specific objective of the present study is to investigate and validate numerical simulations of a fluidic actuator, which is based on the design of Guyot et al 14 The numerical simulations are based on unsteady Reynolds-averaged Navier-Stokes equations (URANS) considering a turbulent, incompressible, and isothermal flow. In order to assess the dependency of the solution concerning reduced dimensional approaches, two-and three-dimensional simulations were conducted and compared.…”

The time-resolved natural flow field of a fluidic oscillator

“…In recent years, these devices have gained renewed interest as flow control actuators. Numerous studies have demonstrated their potential for separation control (e.g., Seele et al 2009;Cerretelli and Kirtley 2009;Phillips and Wygnanski 2013;Woszidlo et al 2014), combustion control (e.g., Guyot et al 2009), and noise control (e.g., Raman and Raghu 2004). Although fluidic oscillators have been successfully employed for flow control, the information available on their fundamental internal and external dynamics remains limited.…”

Computational Characterization of the Feedback Free Fluidic Oscillator

“…A previous experiment saw up to a 40% reduction in combustion instability pressure oscillations when modulating the fuel flow with a fluidic oscillator in a bluff body combustor. 14 In addition, the oscillating jet action of the fluidic oscillator can be used to enhance mixing thereby increasing combustion control. Fluidic oscillators offer a step forward in combustion control due to their high reliability as they require no power or moving parts to operate.…”