## 1 Introduction  
The reduction or enhancement of the lift and drag forces on any bluff-body via modifying the boundary layer employing Active Flow Control (AFC), must be regarded as a novel technology. The use of pulsating flow in (AFC) applications, allows reducing the energy required to modify the boundary layer around a given bluff body. Zero Net Mass Flux Actuators (ZNMFA) and Fluidic Oscillators (FO), are two good candidates to generate pulsating jets, the later having the advantage of employing no moving parts, therefore increasing its reliability. Although there exist few canonical shapes on (FO), it is of major interest to investigate the (FO's) performance when modifying their internal dimensions, then oscillation amplitude and frequency are expected to change. The present paper aims to bring some light to this matter. One of the initial evaluations of the fluidic oscillatorsperformance when modifying its internal shape, was made in 2013 by [PERSON] et al. [1], they made some suggestions regarding the mixing chamber inlet width in order to modify the fluidic actuator output frequency. [PERSON] et al. [2] studied, using the lattice Boltzmann method and based on the solver PowerFLOW, two different configurations of sweeping jet fluidic oscillators (FO), which were further analyzed in 2015 by [PERSON] et al. [3]. The two (FO) considered, resemble the ones studied by [PERSON] et al. [1] and [PERSON] et al. [4] respectively. Velocity profiles generated by the (FO) in quiescent air were compared with experimental data, results showed that the (FO) having sharp internal corners, similar to the one employed in [1], generated an output velocity distribution much more homogeneous than the oscillator having rounded internal corners. The results from the two different configurations were compared to identify similarities and differences between the designs, suggestions of how these differences may affect applications, were made. [PERSON] et al. [5], studied the same configuration previously evaluated by [PERSON] et al. [6]. Both configurations resemble the one studied by [PERSON] et al. [1], the main differences resided in the output shape. In [PERSON] et al. [5] and [PERSON] et al. [6], just a single output was considered. In this new paper, [PERSON] et al. [5], focused their attention in analyzing the flow phenomena inside the mixing chamber and the feedback channels. They also observed that, the increase of the mixing chamber inlet width was tending to increase the output frequency, and rounding the feedback channels would diminish the generation of the separation bubbles on these channels. [PERSON] and [PERSON] [7], studied using 2D-URANS with the software Fluent a range of feedback channel (FC) geometry parameters, the sweeping jet actuator configuration was the same as the one analyzed by [PERSON] et al. [4]. The effects of varying the feedback channel height and width for different mass flow rates were studied. All the simulations were performed for a fully-turbulent compressible flow, using SST k-omega turbulence model. It was found that, oscillation frequencies increased with increasing feedback channel height, up to a certain point and then remained unaffected, however, frequencies decreased by further increasing the feedback channel width. An experimental and numerical study of a fluidic oscillator which could generate a wide range of frequencies (50-300 Hz), was studied by [PERSON] et al. [8]. Their study focused on the oscillation frequency response for different lengths of the feedback channels, 2D compressible simulations were performed using sonicFoam with k-epsilon as turbulence model. An inverse linear relation between frequency and the length of feedback loops was observed, frequency increased when decreasing the feedback channel length. In 2018, the same configuration previously employed by [1], although now using a single exit, was numerically evaluated in 3D at Reynolds 3000 using the SST turbulent model by [PERSON] and [PERSON] [9].