# Analysis of a Novel Fluidic Oscillator under Several Dimensional Modifications
## 6 Results
### Mixing Chamber Internal Angle Modification
For the same three MC angles already introduced in Figure 16, the unsteady maximum stagnation pressure measured at the MC outlet lower inclined wall, the pressure momentum term measured at the lower FC outlet, the mass flow momentum term measured at the same location, and the net momentum acting over the jet as it enters the mixing chamber (which considers the instantaneous pressure and mass flow terms at both FC outlets) are presented in Figure 17a-d, respectively. Focusing on the stagnation pressure (Figure 17a), it is observed that as the MC inclined angle increases, the stagnation pressure peak-to-peak amplitude decreases, the maximum pressure becomes smaller, and the signal appears to have a higher degree of randomness. A similar trend is observed when evaluating the pressure momentum term at the FC lower outlet. The trend is also similar when considering the mass flow momentum at the FC lower outlet and the overall net momentum acting over the jet as it enters the MC, yet these two momentum signals are smoother than the previous pressure signals described since they are obtained from the integration of the respective values across the FC outlet surfaces. These effects seem understandable when considering that the increase in the MC internal angle brings a higher degree of freedom to the jet inside the MC and, as a result, the jet impinges in a wider area along the MC converging walls. The stagnation pressure has a higher associated randomness, the maximum stagnation pressure becomes smaller, and less particles impinge in a given point and at a given instant. The same pattern is observed in the rest of the variables since all of them correlate with the unsteady stagnation pressure. Figure 17: _Cont._  
All graphs presented show a small increase in frequency as the MC inclined angle increases. When considering the FO outlet mass flow, the frequency increase is about 15%; such frequency increase rises to around 20% if the FC mass flow is evaluated. As already observed when analyzing the Reynolds and the MC outlet width cases, the pressure momentum term measured at the FC lower outlet (Figure 17b) is several orders of magnitude higher than the mass flow momentum term (Figure 17c) measured at the same location. Yet, when evaluating the mass flow momentum term measured instantaneously at both FC outlets and comparing it with the pressure momentum term analyzed in the same location (see the figures in Figure 18a,b, respectively) it can be concluded that both momentum terms have the same order of magnitude. The momentum pressure term is about 400% higher than the mass flow term. The corresponding velocity and pressure fields for the minimum (Angle 1) and maximum (Angle 3) angles evaluated are introduced in Figure 19. Small MC inclined angles direct the flow towards the MC outlet; this results in a higher stagnation pressure at the MC inclined wall (see Figures 17a and 19a,b). As the MC inclined angle increases, the jet inside the MC has a higher degree of freedom, this results in a higher degree of random oscillations and a smaller stagnation pressure at the MC inclined walls (see Figures 17a and 19c,d). Small MC inclined angles generate higher maximum instantaneous FO outlet velocities, but appearing only at the center of the jet, which entails smaller outlet mass flow amplitudes. Large MC inclined angles create outlet jets with much more uniform velocity distributions, being the FO outlet peak-to-peak amplitude larger, as observed when comparing Figures 16a and 19a,c. Figure 17: Unsteady stagnation pressure measured at the mixing chamber lower inclined wall (**a**). Pressure momentum term measured at the FC lower outlet (**b**). Dynamic mass flow momentum term measured at the FC lower outlet (**c**) and the instantaneous net momentum obtained when considering pressure and mass flow momentum terms at both FC outlets (**d**). All graphs consider three different MC angles, the smallest (Angle 1), the standard case (STD) and the largest one (Angle 3) studied in the present study.