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The hydrodynamic aspects of functioning of a high-voltage infiltration nanogenerator employing the potential energy of a liquid entering a glass filter are considered. This energy transforms into electric energy due to the formation of a double electric layer owing to the triboeleсtrification effect during the infiltration of the dielectric liquid through the porous structure. To solve the emerged problems, two local effective parameters were introduced in the equations of a hydrodynamic flow along the infiltration path: mechanic density and dynamic viscosity. The working equations for the motion of the liquid were derived; the solutions for the velocity and the flow rate that determine the electric characteristics of a nano-generator—the electric charge and potential as well as their physical relationships—were obtained.

The mechanisms of electrification of various solids in contact or friction, as well as in the interaction of liquid media with conductive and dielectric materials, are described and analyzed. The output characteristics of nanogenerators based on the phenomenon of electrification of solids and liquids are considered. The design and the study results of an electrostatic nanogenerator based on the electrification of a glass porous structure when a dielectric fluid passes through it are presented.

The use of dimensional analysis to solve some problems of hydrodynamics associated with convective transport of a liquid medium is presented. In particular, this forms the basis of deriving equations of continuity, thermal conduction, diffusion, and motion of ideal (Euler) and viscous fluids (Navier–Stokes), with some complements from the field of electrohydrodynamics. In addition, the problem of the presence of two forces of viscous friction is solved, and the problems of sliding and deformation (in compression–extension in a compressible fluid). Formulas for these forces are derived.

The characteristics of a multistage electrohydrodynamic converter (EHDC) have been studied, and the results are presented in this paper. The diagram of an experimental installation is described; the pressure head, flow rate, and current characteristics are provided as a function of time and the EHDC supply voltage. The factors determining the EHDC parameters and the methods of their regeneration are determined.

This work is aimed at the study of the corona-discharge motor (CDM), whose torque is produced due to the electric dipole moment, which appears at the corona discharge. The physical mechanisms and features of the CDM operation that allow us to form a calculation base for the design and construction of the CDM, are identified and discussed. The motor power consumption, dipole moment generation, rotor torque as well as some specific effects inherent to this type of motor, arising from numerical calculations which take the pulse character of the supply voltage of the corona discharge into account, are considered. It is found that the motor rotation at a constant angular rate and a synchronous rotation with the torque are impossible. The obtained results can be used as a prerequisite for engineering calculations of the corona-discharge motors.

The principle of operation of an electrohydrodynamic pump (EHDP) is explained. Research problems are formulated for the study of the patterns and peculiarities of the operation of the EHDP for the purpose of its optimization. The experimental facility is described and the peculiarities of the relaxation of the output characteristics of a single-stage EHDP are determined. The dependences of the pressure and current characteristics on the time and voltage (dc) supplied to the EHDP are presented. New results related to very long operation of EHDPs are revealed, e.g., the fact that the pressure characteristics are fluctuating time functions. A theoretical model of the electric current transfer in an EHDP is presented, which is based on an analog electrical circuit.

The influence of the spatial orientation of an evaporator–condensing system (ECS) on the heat transfer coefficient is considered. As found, it varies according to the cosine law, which implies that it is at its minimum when the evaporator is in the top position, and it is at its maximum when the heater is in the bottom position. This is consistent with the physical considerations about the effect of buoyancy forces on heat transfer. The average velocity of coolant circulation through the ECS loop is found, and on this basis, the “electric” Reynolds number and heat transfer coefficient are estimated. The influence of pressure on heat transfer in the ECS has been analyzed. The considered phenomena have been physically interpreted; they agree well with the experimental data.

The dependences of the parameters of corona discharge current–voltage characteristics on the gas temperature are considered in this work. It is shown that the corona discharge ignition voltage U c (T) of helium and nitrogen decreases with the increase in temperature. The dependence of the parameter A(T) is complicated. It increases at the initial and final sections of the studied temperature range (20–369°C) and decreases at its central portion with two extrema. As the discharge in nitrogen is unstable, we failed to obtain any definite regularity. Generalized dependences that make assertions about the presence of a discharge different from a corona are presented. We made an assumption of an important role of two effects in the observed processes: the absorption of ions by the surface of electrodes and the continuous change in ion mobility due to the ion mass variation in the course of clustering and declustering of ions. It is supposed that there is a dynamic equilibrium between them in a steady state.

The semiempirical dependencies of parameters A(p) and Uc(p) of corona-discharge current–voltage characteristics on pressure in the range from 0.5 to 2.0 MPa at T = 293 K for helium and from 0.4 to 0.7MPa at T = 473 K for nitrogen are obtained on the basis of the statistical treatment of experimental data and theoretical presumptions. For helium, the parameter A(p) decreases inversely with pressure while a similar dependence for nitrogen has a minimum. Its physical nature calls for further investigation.

The construction and operation of a small-sized electrostatic engine are described. It consists of a rotor in the form of a thin-walled cylinder made from a dielectric material. There are two strips of metal foil along the two diametrically opposite generatrices of the cylinder. The gap between the longitudinal edges of the strips can be varied. Similarly, two electrodes, in the form of thin rigid plates with sharp edges facing the cylinder surface, are diametrically opposed to each other and parallel to the generatrices of the cylinder. Distances from the sharp edges to the surface of the cylinder have been varied. The device is powered by a highvoltage DC source providing a symmetrical bipolar corona discharge. Experimental dependences of the engine speed on the voltage between the electrodes for different geometrical parameters are given. Regression equations are derived and presented in a graphical form. An analytic substantiation of the engine operation principle is presented, and experimental and theoretical results are discussed.

Generalizations from the experimental current-voltage characteristics of corona discharge for helium and synthetic air at the positive and negative polarities of a star-shaped discharge electrode at different gas pressures are presented. Similar generalizations are performed for current-voltage characteristics obtained for dried air and a coaxial system of electrodes at various temperatures and atmospheric pressure. The generalization consists in reducing the family of the current-voltage characteristics to a single generalized equation that geometrically represents a segment bisector. Some aspects of the application of similarity methods for corona discharge are considered. Townsend’s structure of the characteristics is confirmed, and this fact can serve as a basis for its wide application.