To the Calculation of a Closed Hydraulic EHD System

The purpose. To study the possibility of describing electrohydrodynamic processes in an EHD transducer with planeparallel grid electrodes, taking into account local hydraulic resistances.

Methods. Using the method of integral relations and non-dimensionalization of variables that determine the force parameter of the Coulomb field and hydraulic resistance, on the one hand, and the value of unipolar charge formation, on the other, practically important relations for a cylindrical EHD system are obtained. By tabulating the dimensionless parameters characterizing the system, the effective modes of operation of a grid cylindrical EHD transducer are considered. The method of using the empirical relations of hydraulics made an assessment of the influence of local hydraulic resistance on the pressure characteristics of the system. Comparison of calculations with experimental model is carried out.

Results. The modes of operation of a grid EHD transducer included in a closed hydraulic circuit are considered depending on dimensionless variables, on the one hand, expressing the level of charge injection of one of the electrodes, and, on the other hand, the power characteristic of the electric field and the magnitude of the hydraulic resistance of the external contour of a circular cross section . An engineering assessment is made of the influence of local hydraulic resistances, electrode grids with a given geometry, and sudden expansions and contractions of the working fluid flow on variable sections of a specific cylindrical structure of the EHD system on the pressure drop.

Conclusion. For a fixed dimensionless parameter that characterizes the hydraulic resistance of the external circuit and the force effect of the interelectrode electric field, there are interval values of the parameter that determines charge injection, at which the efficiency of the grid EHD system is maximum. Even at low speeds, the resistance of the mesh electrodes significantly reduces the pressure created by the pump (up to 50%). At high hydraulic resistances corresponding to static pressure characteristics, the considered model satisfactorily describes the characteristics of the EHD system.

1. Zhakin A. I. O nekotorykh raschetnykh skhemakh EGD nasosov na osnove redoks-sistem [On some design schemes for EHD pumps based on redox systems]. Elektronnaya obrabotka materialov = Electronic processing of materials, 1988, no. 3, рр. 35–37.

2. Polyansky V. A., Pankratieva I. L. Modelirovanie elektrogidro-dinamicheskikh techenii v slaboprovodyashchikh zhidkostyakh [Modeling of electrohydrodynamic flows in weakly conductive liquids]. Prikladnaya mekhanika i teoreticheskaya fizika = Applied mechanics and theoretical physics, 1995, vol. 36, no. 4, pp. 36–43.

3. Kuznetsov S. F., Molotov P. E., Parinov Yu. V. Zavisimost' KPD EGD nasosov ot gidrosoprotivleniya nasosov [Dependence of efficiency of EHD pumps on hydraulic resistance of pumps]. Elektronnaya obrabotka materialov = Electronic processing of materials, 1988, no. 1, рр. 43–45.

4. Vartanyan A. A., Gogosov V. V., Polyansky V. A., Polyansky K. V., Shaposhnikova G. A. Modelirovanie nestatsionarnykh protsessov v kanalakh EGD-nasosa [Modeling of non-stationary processes in the channels of the EHD pump]. Mekhanika zhidkosti i gaza = Mechanics of liquid and gas, 1994, no. 3, pp. 30–41.

5. Stishkov Yu. K., Ostapenko A. A. Elektrogidrodinamicheskie techeniya v zhidkikh dielektrikakh [Electrohydrodynamic flows in liquid dielectrics]. Leningrad, Leningrad St. Univ. Publ., 1989. 176 p.

6. Kuznetsov S. F., Molotov P. E., Parinov Yu. V. K teorii elektrogidrodinamicheskogo effekta [To the theory of electro-hydrodynamic effect]. Magnitnaya gidrodinamika = Magnitnaya hydrodynamics, 1986, no. 2B, рр. 94–99.

7. Stishkov Yu. K., Ostapenko A. A., Makarov P. A. Elektrogidro-dinamicheskie preobrazovateli [Electrohydrodynamic transducers]. Magnitnaya gidrodinamika = Magnetic hydrodynamics, 1982, no. 2, pp. 120–125.

8. Kozhevnikov I. V. Teploobmen v zamknutykh tsirkulyatsionnykh konturakh pod vozdeistviem elektricheskogo polya. Diss. kand. tekhn. nauk [Heat transfer in closed circulation circuits under the influence of an electric field. Cand. eng. sci. diss.]. Kishinev, 1993. 207 p.

9. Bologa M. K., Kozhukhar' I. A., Usenko V. P., Shkilev V. L., Mardarsky O. I. Eksperimental'noe issledovanie elektrogidrodinamicheskogo nasosa [Experimental study of an electrohydrodynamic pump]. EOM, 1982, no. 5, pp. 74–76.

10. Kozhukhar I. A., Shkilev V. D., Bologa M. K., Volshina T. A. Elektrogidrodinamicheskii nasos [Electrohydrodynamic pump]. Patent USSR, no. 3427071/24–25, 1982.

11. Stishkov Yu. K. Elektrofizicheskie protsessy v zhidkostyakh pri vozdeistvii sil'nykh elektricheskikh polei [Electrophysical processes in liquids under the influence of strong electric fields]. Moscow, Yustitsinform Publ., 2019. 262 p.

12. Roldugin V. I. Samoorganizatsiya nanochastits na mezhfaznykh poverkhnostyakh [Self-organization of nanoparticles on interfacial surfaces]. Uspekhi khimii = Advances in Chemistry, 2004, vol. 73, no. 2, рр. 123–156.

13. Liu M., Yang Q., Wu S. Space charge injection behaviors and di-electric characteristics of nanomodified transformer oil using different surface electrode conditions. AIP Adv., 2019, vol. 9, is. 3, рр. 035319.

14. Wu S., Yang Q., Shao T., Zhang Z., Huang L. Effect of surface modifi-cation of electrodes on charge injection and dielectric characteristics of pro-pylene carbonate. High Voltage, 2020, vol. 5, is. 1, pp. 15–23.

15. Russel M., Selvaganapathy P., Ching C. Effect of electrode surface topology on charge injection characteristics in dielectric liquids: an experimental study. J. Electrostat., 2014, vol. 72, is. 6, pp. 487–492.

16. Walvekar R., Zairin D. A., Khalid M., Jagadish R., eds. Stability, thermo-physical and electrical properties of naphthenic/POME blended trans-former oil nanofluids. Therm. sci. Eng. Prog., 2021, vol. 23, рр. 100878.

17. Amiri A., Kazi, S. N., Shanbedi M., Mohd Zubir M. N., eds. Transformer oil based multi-walled carbon nanotube–hexylamine coolant with opti-mized electrical, thermal and rheological enhancements. RSC Adv., 2015, no. 130, p. 107222.

18. Beheshti A., ShanbediM., Heris S. Z. Heat transfer and rheological properties of transformer oiloxidized MWCNT nanofluid. J. Therm. Anal. Calorim., 2014, vol. 118, no. 3, p. 1451.

19. Kuzko A. E. Osobennosti izmeneniya mikrorel'efa poverkhnostei elektrodov pri elektrokonvektsii v PMS-50 [Peculiarities of changes in the microrelief of electrode surfaces during electroconvection in PMS-50]. Izvestiya Yugo-Zapadnogo gosudarstvennogo universiteta. Seriya: Fizika i khimiya = Proceedings of the Southwest State University. Series: Physics and Chemistry, 2014, no. 1, рр. 24–30.

20. Kuzko A. E., Kuzmenko A. P., Lazarev A. N. Ispol'zovanie ASM v raschete inzhektsii zaryadov pri elektrokonvektsii [The use of AFM in the calculation of charge injection during electroconvection]. Izvestiya Yugo-Zapadnogo gosudarstvennogo universiteta. Seriya: Fizika i khimiya = Bulletin of the Southwest State University. Series: Physics and Chemistry, 2013, no. 2, рр. 32–37.

21. Zhakin A. I., Kuzko A. E. Teoriya osesimmetrichnogo elektrogidrodinamicheskogo nasosa [Theory of an axisymmetric electrohydrodynamic pump]. Elektronnaya obrabotka materialov = Electronic Processing of Materials, 2000, no. 4, рр. 44–53.

22. Zhakin A. I., Lunev S. A. Analiz raboty setochnogo EGD nasosa, vklyuchennogo v zamknutyi gidravlicheskii kontur 1. Priblizhennaya teoriya [Analysis of the operation of a grid EHD pump included in a closed hydraulic circuit 1. Approximate theory]. Magnitnaya gidrodinamika = Magnetic hydrodynamics, 1998, vol. 34, no. 3, рр. 273–279.

23. Altshul A. D., Kiselev P. G. Gidravlika i aerodinamika [Hydraulics and aerodynamics]. Moscow, Stroyizdat Publ., 1975. 326 p.