# Influence of Baffle Location on the Diodicity of Tesla Valves
## 3 Results and Discussion
### Influence of Flow Field Non-Uniformity at Two Locations on the Diodicity  
Based on the aforementioned findings, we can further refine the design of the TV to more precisely simulate the impact of flow field non-uniformity on its diodicity. Among the four optimization cases previously discussed, it was observed that the non-uniform flow field induced by baffles positioned at the outlet can significantly enhance the diodicity of the TV. Leveraging this insight, Cases 5 to 8 have been proposed, as illustrated in Figure 3. These cases involve pairs of baffles positioned at four distinct locations. The aim of these new cases is to explore the influence of the non-uniform flow field generated by baffles placed at the inlet on the diodicity of the TV. The pressure drops for the forward and reverse flows in Cases 5 to 8 are presented in Figure 15a,b. The pressure drop exhibits a variation that approximates a quadratic curve in relation to the Reynolds number. In forward flow, the pressure drop curves for Cases 5 and 8, as well as for Cases 6 and 7, are essentially congruent. This congruence implies that the non-uniform flow field induced by the baffles, when relocated to the inlet of the TV, exerts a negligible influence on the pressure difference observed during forward flow. In reverse flow, a significant difference is observed between the pressure drop curves of Case 5 and Case 8. The curves for Case 6 and Case 7, while exhibiting a smaller difference, also deviate noticeably from the congruence observed in the preceding forward flow phase. This indicates that the repositioning of baffles at the inlet of the TV has a considerable impact on the pressure drop during reverse flow. This impact can be either beneficial or detrimental. As depicted in Figure 16b, the diodicity of Case 5 is even poorer than that of the case without added baffles, while the diodicity of Case 8, which incorporates two baffles, is further optimized compared to Case 4, which features only one baffle. Figure 15a also demonstrates that baffles positioned downstream of the inlet enhance diodicity, whereas those positioned upstream of it reduce it. During forward flow, the fluid predominantly traverses the straight channel branch situated below the arc channel branch, culminating in a heightened pressure drop relative to the case without baffles. However, among cases with an equivalent number of baffles, there is scant variation in the frictional resistance encountered by the fluid, and no substantial alteration in the pressure drop is observed across different cases. Figure 15: Pressure drops over various Tesla valve cases (from cases 5 to 8). (**a**) Forward flow and (**b**) reverse flow. In the reverse flow process, in contrast to the preceding optimization case, a vortex is formed above the inlet. In Cases 5 and 7, the baffle positioned above the inlet supplants the vortex effect, exerting a negligible influence on the original flow field and permitting the fluid to pass through with minimal resistance. Nevertheless, the baffles positioned below the inlet in Cases 6 and 8 markedly impede the flow, culminating in an escalated pressure drop. From the analysis presented, it is clear that the optimization of diodicity is primarily contingent upon the strategic positioning of baffles at the outlet. The installation of baffles at the outlet is a critical factor, and the subsequent addition of baffles at the inlet can further modulate the diodicity. Upon comparing the initial four cases, each with a single baffle, to the subsequent four cases with multiple baffles, it is noted that cases with two baffles exhibit diverse impacts on diodicity optimization. Generally, positioning a baffle below the inlet tends to achieve more favorable optimization results. In contrast, positioning a baffle above the inlet may adversely affect the valve's performance. During the optimization of the Tesla Valve's (TV's) structure, it is observed that forward flow predominantly traverses the straight channel branch with minimal hindrance.