Valve Author: Vera Lyabzina, AESC MSU, Moscow, Russia Supervisor: Sladkov Klim, student of MSU 1. Introduction 3. Results

A Tesla valve is a fixed-geometry, passive, one-direction Using results got from expirements with different α and β valve which resists to flow that is much greater in one (see Fig.2) dependence of Di on α is nonmonotonic, achieve direction compared to the other. The main principle of the the maximum in α ≈50 о -60о. valve is that the stream going through it separates into two streams. Those streams go the way which would reduce It was established that while I increased distance between their kinetic energy. stages diodicity monotonic decreased. Minimal diodicity is equal one-stage valve diodicity. 2. Research Methods The velocity of the stream reduces on every stage. The more The goal of my work is to create Tesla valve and investigate stages there are, the bigger reduction of the velocity is. As what parameters affect the diodicity of the valve. Diodicity the result, diodicity increases: (Di) is the main characteristic of any valve that characterize 푣 =푣 ∗푒 ∗ 푐표푠훼 + 2푐표푠훽 (2) difference of flow resistance in forward and in reverse directions 푣 =푣(1−(푒 ∗ 푐표푠 훼 + 2푐표푠훽) ) (3) 푣 푟푒푠푒푟푣푒 퐷푖 = (1) 푣 푓표푟푤푎푟푑 푣 - velocity in starting point, 푣 - velocity in ending point, 푣 – velocity drop after n stages I have modeled Tesla valve in Kompas-3D.

Fig.1 3D model of the Tesla valve

Then I have created valve on 3D printer.

Graph 1 – The dependence of the Diodicity by the quantity of stages.

Fig.2 printed Tesla valve 4. Conclusion

푝 푟푒푠푒푟푣푒 – pressure drop in reserve direction, 푝 푓표푟푤푎푟푑 – pressure In the course of this work I have modeled and created the drop in forward direction, 푝 - pressure in starting point, 푝 - Tesla valve, have studied its characteristics and have pressure in ending point, 푣 푟푒푠푒푟푣푒 – velocity drop in reserve direction, investigated parameters and their effect on the valve 푣 푓표푟푤푎푟푑 - velocity drop in forward direction diodicity. In my work I measured diodicity as follows : A little piece of rubber was put on the water near the input of the valve. 5. References And used Tracker program to calculate the velocity of [1] T.-Q. Truong and N.-T. Nguyen. Simulation and rubber in forward and reverse directions of valve. Then I Optimization of Tesla Valves. Tech. Proc. Nanotech 2003, used (1) to count the diodicity. vol. 1 (2003)

[2] S. M. Thompson, B. J. Paudel, T. Jamal and D. K. Walters. Numerical investigation of multistaged Tesla valves. J. Fluids Eng. 136, 8, 081102 (2014)