# Influence of Baffle Location on the Diodicity of Tesla Valves
## 2 Problem Setup
### Experiment Methods  
The experimental setup, as shown in Figures 7 and 8, consists of the following main components: a water tank, control valves, a pressure transducer (YK-100B, Xi'an Shelok Instrument Technology Co., Ltd., Xi'an, China, with a range of 0-10 kPa and an accuracy of 0.05%), a Tesla Valve (TV), a peristaltic pump (BT300J-1A, Yuhui Fluid Equipment Co., Ltd., Yangzhou, China), and a graduated cylinder. The Tesla Valve is manufactured using advanced 3D printing technology, precisely meeting the parameter requirements specified in this study. This 3D printing technique enables the precise fabrication of complex geometries that align with the Tesla valve's flow characteristics, ensuring optimal Di performance. Notably, 3D printing not only accelerates prototyping but also offers cost-effective and flexible manufacturing solutions [34; 35]. Additionally, its compatibility with diverse materials expands the potential for functional optimization [35]. This approach guarantees the reliability and repeatability of the experiment. The water tank, measuring 30  
Figure 5: Di vs mesh number of a single-stage Tesla valve at Re 300. Figure 6: The linear relationship between Di and the Reynolds number [23; 28]. \(\mathrm{cm}\times 30\ \mathrm{cm}\times 50\ \mathrm{cm}\), serves as an effective pressure source due to its large volume and stable structure, providing a continuous and stable water flow for the experiment. Control valves play a crucial role in the experiment; by accurately adjusting the opening and closing states of the valves, the direction of water flow can be flexibly guided, achieving precise control over the experimental process. Before starting the experiment, it is necessary to operate the valves to expel the air from the Tesla Valve to eliminate the interference of bubbles on the experimental results: open valves 2 and 3 to allow the air to be smoothly discharged, while closing valve 1 to prevent water from entering the Tesla Valve prematurely. During the experiment, water is stably delivered from the tank to the Tesla Valve by opening valves 1 and 3 and closing valve 2, ensuring that the experiment proceeds smoothly under predetermined conditions. After the experiment, water is recirculated back into the tank by opening valves 1 and 2 and closing valve 3, maintaining a stable water level. The flow rate is controlled by adjusting the water level in the tank, and the flow velocity is calculated by measuring the change in water volume in a specified period using the graduated cylinder. The height of the water level in the tank affects the fluid velocity. When the water level rises, the fluid velocity increases accordingly; conversely, when the water level drops, the velocity decreases. By controlling the water level in the tank, the inflow and outflow rates of the tank can be adjusted. The key to this process lies in utilizing a graduated cylinder, a fundamental measuring tool, to observe and record the subtle changes in water volume over a set time interval. This allows the adjustment of water level to be translated into specific flow rate values, laying a solid foundation for the accuracy of subsequent experimental data. In this experiment, the Reynolds number spans from 100  
Figure 8: Physical diagram of the experimental system. Figure 7: Schematic diagram of the experimental system. to 300, calculated using Equation (4). It ingeniously integrates physical quantities such as fluid velocity, density, and viscosity, providing a critical basis for determining the state of fluid flow. At a Reynolds number of 300, the flow rate through the Tesla valve is precisely determined to be 36 milliliters per minute, a result obtained through rigorous control of water level adjustment and flow rate measurement. The inlet Reynolds number can be defined as follows:  
\[\text{Re}=\rho vd/\mu \tag{4}\]  
where \(\rho,v,\text{ and }\mu\) are the density, velocity, and dynamic viscosity of the fluid, respectively. While \(d\) denotes a characteristic length, which, in this case, is the hydraulic diameter.