The dynamic development and enhancement of the efficiency and safety of power engineering in the Arctic and remote Siberian regions of Russia are promising and relevant. The aim of this work is search for scientifically based approaches and methods against icing, which is one of the main problems hindering efficient use of wind turbines for autonomous power supply to remote settlements in the Far North. The necessity in the research and its relevance are confirmed by the growing interest in the development of the Arctic region by the leading world countries. The presented research strives for an optimal strategy against icing of wind turbine blades in climatic conditions typical of the Arctic coast of Russia. The efficiency of combined anti-icing methods relying on the use of aerodynamically transparent substrates, hierarchical superhydrophobic (HSH) coatings, and materials based on polytetrafluoroethylene fiber for wind turbine blades in Arctic climatic conditions was experimentally studied. It is a fundamentally new approach, which has no world analogues. For verification of the efficiency of the de-icing systems and identification of the most efficient protection methods or combination of them, an experimental comparison was made for the efficiency of superhydrophobic coatings when used separately and together with various traditional de-icing methods based on heaters and ultrasonic and vibration devices. It has been shown that the integral use of the proposed methods and approaches successfully solves the problem of developing a general anti-icing strategy.

Detailed experimental data on the kinematic characteristics of the flow in a vortex tube along its entire length are presented and analyzed. Experimental data obtained in a vortex tube with square cross-section of the working channel were compared at three values of the cold mass fraction: 0.4, 0.5, and 0.75 with the air expansion ratio in the apparatus of π=5 . The behavior of standard deviations from the mean values of velocity components is analyzed. The noticeable peaks in the percentage of standard deviation from the longitudinal mean velocity component are observed in the area of the near wall flow temperature growth along the tube.

The effect of icing on the kinematic and power parameters of the working element of a wind generator blade was experimentally studied using a modified laser Doppler anemometry method. Arctic conditions were modeled in a specially designed aerodynamic climatic setup based on an optically transparent plexiglass tube with a square cross section of 200×200 mm with the following parameters: flow velocity of up to 20 m/s, temperature of up to −20 °C, and relative humidity of up to 90

The paper discloses the study of flow crisis in the Ranque—Hilsch vortex tube with a square channel. Previous studies have found the conditions for developing the hydraulic crisis for air flow in this type of tube. The crisis phenomenon is related to the event when the longitudinal velocity at the nearwall vortex-circulation zone interface approaches the value of velocity for spreading centrifugal waves along this boundary. The paper presents and discusses the new detailed results in measuring the kinematic parameters of the crisis flow, including the parameter of velocity pulsation. The evidence of a hydraulic jump near the exit of the swirl flow to the tube working channel.

We study the possibility of application of the methods of laser Doppler anemometry for the noncontact measurement of the velocity of moving media in various phase states. We mention the specific features of the conditions of application of laser Doppler anemometers and, in particular the fact that, in numerous cases there exist restrictions on the use of photomultipliers. With an aim to find an alternative to the classical photomultiplier of a laser Doppler anemometer, we study three types of photomultipliers: classical electric vacuum photomultipliers, silicon avalanche multipixel photomultipliers, and photomultipliers with microchannel plate. We performed physical experiments aimed at measuring the velocity of aero- and hydrodynamic flows by laser Doppler anemometers with photomultipliers of the indicated three types. Actually, we measured the velocities of a rotating glass disk, of an aerodynamic flow in a channel with rectangular cross section, of an aerosol flow, and of a flooded hydrodynamic jet. The accumulated experimental data are analyzed according to the criteria of evaluation of the quality (efficiency) of operation and the ranges of applicability of the specified photomultipliers. By analyzing the physical properties of the investigated photomultipliers, we clarify their efficiency characteristics in different experiments. The ranges of efficient applications of these photomultipliers are determined for a broad class of physical experiments. The obtained results are of high importance for the researchers involved in the study of aero- and hydrodynamic flows in which it is necessary to have accurate and reliable result of measurements of the flow velocity. The optimal choice of a photomultiplier for the laser anemometers makes it possible to increase the accuracy, simplify the procedure of collecting the experimental data, and to reduce the cost of the final equipment.

The gas temperature measurements at the level of the inner wall of Ranque vortex tubes of the square and circular cross sections with variations in the cold mass fractions for both tubes showed the presence of three characteristic zones of temperature growth, which do not change over a wide range of the cold mass fraction. These zones are typical when analyzing the flow in a vortex tube within the framework of the flow crisis concept.

Полякова 1 , М. Х. Правдина 1 , И. К. Кабардин 1 Применение визуализации методом лазерного ножа для исследования поворотно-расширяющегося потока 1 Институт теплофизики им.С. С

Исследование кинематики потока в структурированном многослойном каталитическом картридже1 Институт теплофизики им.С. С. Кутателадзе СО РАН, г.Новосибирск, Российская Федерация

С. В. Какаулин 1 *, В. Г. Меледин 1 , И. К. Кабардин 1 Апробация лазерного доплеровского анемометра ЛАД-08 на вторичном эталоне единицы скорости воздушного потока 1 Институт теплофизики им.С. С. Кутателадзе СО РАН, г

The results of studies of superhydrophobic surfaces under conditions of icing on a climatic aerodynamic stand are summarized. The prospects and limitations of using plastic polymer coatings for anti-icing systems of wind turbine blades are shown. The effect of destruction by ice of superhydrophobic surfaces with coatings with nanograss and nanooutgrowths in an aerodynamic flow has been investigated. The resistance to destruction by icing has been established only for linear microstructures imitating depressions on the nanostructure in the form of lotus leaves. A simple mathematical model has been adapted to illustrate the effectiveness of various nanostructured formations on a solid surface in dependence on the blowing speed and wetting angle. The results obtained are of interest for development of anti-icing systems for structures with plastic coatings (wind turbine blades, protective plastic elements of bridges, oil platforms, etc.).

The results of studies on reducing ice adhesion via change in the original shape of the blade profile and its surface by means of microstructuring of different geometries are summarized. The influence of the height of nanograss on the intensity of ice formation was estimated for coatings investigated under icing conditions on a climatic aerodynamic stand for study of icing on model blades of wind turbines. The prospects and limitations of using polymeric plastic coatings for anti-icing systems for wind turbine blades are shown.

In this work, a method of low-perturbation temperature diagnostics in the Ranque–Hilsch vortex tube is developed. The method is based on scanning of temperature with a set of up to eight special small sensors. The temperature profiles were synchronously recorded in different cross sections of the vortex tube. Contour maps of temperature distribution have been constructed.