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The paper presents results of numerical simulation for development of localized disturbances emerging from a single source or double synchronous sources in a laminar boundary disturbances at the plate with the flow with the Mach number М = 2 (variants for different distances between sources). Simulation was performed using the FlowVision software complex at the parameters typical for T-324 wind tunnel (developed by ITAM SB RAS). The problem was studied in the range of linear development of disturbance. The study demonstrates that, depending on the distance between the sources, the generated disturbances might either enhance or decay in the downstream flow. The frequency-wavelet analysis of disturbance structure was performed. Two distanced local synchronous sources generate the disturbances with wavelet spectra: these spectra exhibits nodes and crests; their positions depend on the distances between two sources.

A technique is described and the results of an experimental study of the aerodynamic structure of a turbulent streamlining, velocity fluctuations and pressure fields on the surface of a single trench hole located on the wall of a flat rectangular channel are presented. The trench hole cross-section is a cylindrical segment with hemispheres at its edges. The measurements were carried out with a two-component laser-Doppler velocity meter at two angles of hole inclination relative to the flow direction φ=0 и 45°. The development of the flow in the direction transverse to the trench, as well as along its span, was studied. The fundamental difference between the velocity fields and their fluctuations in a trench located normally and at an angle to the flow is shown.

The paper is the study of electric resistance of a graphene layer washed by a liquid with different flow rate parameters. Experiments demonstrate that if the fabricated composite (graphene upon a PET/EVA polymeric substrate) is submerged into distilled water, the sample resistance increases by 120 %. Meanwhile, the flow of liquid near the graphene layer decreases this gain in the electric conductivity. The effect offers a general design of a flow rate sensor based on the graphene layer, taken as a sensitive matrix. The study demonstrates that this design of graphene flow sensor (taken for distilled water) exhibits a linear dependency of the sensor resistance on flow rate.

Results of an experimental study and direct numerical modeling of the steady flow in a channel branching region simulating the proximal anastomosis of the femoral artery, are reported. The Reynolds number was Re = 1500, which value corresponds to the maximum blood flow during the period of heart contractions. The ratio of the rates of the liquid flows through the branch and the main channel was a varied parameter. Regularities in the development of the flow structure in the primary channel and in the branch region are revealed, with much attention having been paid to flow separation regions. The occurrence of secondary flows localized within the separation regions has been established. The ranges of the ratio of the flow rates at which flow turbulence signs appear in the mixing layer at the interface between these regions are determined.

The paper deals with simulation study of aerodynamics and heat transfer for a case of a four-vortex furnace chamber designed for jet fire of brown coal from Eastern coal deposits. The combustion modeling is achieved by a set of linked submodels: they describe turbulent gas flow? Thermal and radiative heat transfer, the processes of degradation and burning of coal particles, NO_x generation. Simulation demonstrated that using of these types of brown coal in a specific-design furnace chamber creates a steady four-vortex flow structure that provides a uniform temperature field in the volume and admissible generation of NO_x .

Laser water jet processing is a new hybrid method developed on the basis of traditional laser processing technology. It combines high laser processing efficiency with the impact and cooling effects of water jets. Laser water jet processing can effectively process hard and brittle materials such as silicon. In-depth study of the processing technology has important practical significance. For this reason, the controlled variable method is used to study the influence of different processing parameters on groove depth. The research results show that with the increase of current and laser pulse width , the groove depth gradually increases; with the increase of laser repetition frequency and water jet velocity, the groove depth increases first and then decreases. The experiment of laser water jet processing silicon can provide guidance for processing other difficult-to-process materials in the future.

Laser radiation is a leading tool in the field of materials processing and design. Recently, the prob-lem of controlled changes in the wetting properties of metals realized by the micro- and nanostructuring of surfaces has been actively investigated. In the pre-sent paper, the influence of the conditions of nano-second laser treatment on the wetting properties of a copper surface in the mode of formation of a ran-domly distributed hierarchical structure is investigat-ed. Special attention is paid to the evolution of the contact angle of wetting over time. The mechanisms of changing the wetting properties over time are con-sidered. It is shown that the overlap of laser spots is more important than the fluence in the beam from the point of view of hydrophobization of the copper surface.

The flow-type microreactors, being designed for small-scale production of pharmaceutical substances, have a moderate volume and ensure steady synthesis for pharmaceutical production while using noninva-sive methods for mixing of ingredients. The paper describes experimental and simulation study of the efficiency for natural convection mechanisms for so-lutions mixing in a Y-type symmetric microreactor. The mixing zone is arranged for discovery of con-vection potential. We consider both variants of chemically inert and chemically active systems. A model reaction is represented by a rapid acid-base neutralization reaction. The theoretical model com-prises the 3D Navier-Stokes equation and the reac-tants transfer equation (written with account for non-linear diffusion). Experimental and numerical results have been compared. The dependency for the effec-tive mixing length on the instability type and sol-vents flow rates was found.

The article presents the results of an experimental study of the cavitation flow around the NACA 0012 series foil in a narrow slit channel with a width of 1.2 mm. The aspect ratio of the streamlined body was 0.02. To identify the main features of the two-phase flow, high-speed visualization was performed using the Photron FASTCAM NOVA S12 camera with a sampling frequency of 20 kHz. The internal structure of cavities was detected. The main frequencies of cavities formation in the flow were determined using digital processing of visualization data. The close location of the channel walls was shown to significantly affect the return flow propagation under the cavity and its separation.

The study is focused on the process of bubble growth inside a intensively evaporating liquid droplet placed on a hot structured surface made of black silicon. Experiments are carried out with volatile fluids FС-72, HFE 7100, ethanol and water. The method using the Schliren-system was developed for study of bubble growth inside a droplet. The contact line speed was measured during microdroplet evaporation, including the case of a growing bubble inside the droplet. The speeds of the contact for droplet evaporation with/without bubble were compared. The contact line instability was found, emerging due to a developed structure of substrate; it facilitates the enlargement of local flows in microregions. This facilitates the heat transfer enhancement.