# roughness

## Analysis of Influence of Pipeline Internal Surface Roughness on Flow Rate Measured by Means of Standard Pressure Differential Devices

The paper presents the analysis of scientific and technical sources on the influence of constructive features of pressure differential flowmeters on flow rate measurement error. According to the research results, the significant surface roughness of pipe sections downstream of the orifice plate does not significantly affect the flow measurement result. The influence of the pipe roughness upstream of the orifice plate depends on geometric characteristics of roughness, the pipe diameter, the relative area of the orifice plate throat, and the Reynolds number.

## Modeling and simulation of machined surface layer microgeometry parameters

The formation of the microtopography of the machined surface is one of the most critical factors in ensuring the effective operating properties of the product. These are indicators such as wear resistance, fatigue strength, provision of friction parameters of moving joints, etc. The most important reason for the formation of microroughness is vibration in the technological surface of the machine-tool-tool-tool-workpiece. This article is devoted to describing a new method of modelling the dynamic processes of machining.

## Topography of the strengthened cylindrical surface after frictional continuous treatment

Friction treatment refers to methods of surface strengthening (hardening) of the parts’ working surfaces using highly concentrated energy sources. Concentrated energy flow is formed during high-speed friction of the tool on the treated surface in the area of their contact. A strengthened (reinforced) white layer with a nanocrystalline structure is formed in the surface layer of the treated surface.

## Equation of Arithmetic Mean Deviation of Roughness Profile

In order to improve the accuracy of gas flowrate measurement by means of the differential pressure flowmeters, it is necessary to apply equations for determination of coefficients of gas flow equation, which would provide the lowest total relative expanded uncertainty of calculation, and to increase the accuracy of input values measurement in real time. One of these values is the arithmetic mean deviation of roughness profile of pipe internal surface. The equation for calculating the arithmetic mean deviation of roughness profile of pipe internal surface in real time was obtained.

## Tribological characteristics of electric arc coatings from powdered wires in technological environment

The research of tribological logic characteristics of electric arc coatings from powdered wires in technological environments was conducted: under conditions of limit lubrication in lubrication I-20;
in the environment of 3 % emulsor of the brand Hydroway 1060 and lubrication M10V2. Coatings in the thickness of 1.2–1.5 mm were applied by serial electro-arc metal with the inhibitor of PMI-1

## Surface structure and roughness of electric arc coatings from powdered wires after grindin

The peculiarities of coating formation by the gas-thermal method at application of powder wires are considered. This is due to the presence of pores and solid inclusions in the resulting layer. Therefore, it is important to investigate the influence of the mechanical processing parameters and the composition of the powder wire on the roughness of the polished surface of the electric arc coatings. Coatings in the thickness of 1.2 ... 1.5 mm were applied with a serial electro-arc metalizer EM-14 on a pre-treated surface of both flat and cylindrical specimens.

## Вплив магнітно-абразивного оброблення на якість мітчиків із швидкорізальної сталі

The specificities of magneto-abrasive machining of cutting taps made from high-speed steel were researched. Surface roughness after cycle machining of cutting taps on the front surface is reduced to Ra=0,1µm, on the back surface to Ra=0,7—0,9µm, on the cylindrical surface — Ra=0,2— 0,4µm, depending on the conditions of basing the machined pieces during machining, surface hardness increases to 9—10GPa, radii of cutting edge rounded increases on 5–10%. It is shown, that the moment for cutting taps at tapping after MAM on 15–40% less than for unmachined taps.

## Зміна характеристик робочих поверхонь деталей при звуковій вібраційній обробці в пружному середовищі

In the article the considered change of basic tribological descriptions of superficial layer of workings surfaces of pair of friction is at their voice oscillation treatment in a resilient environment. The technological parameters of process of treatment and of principle chart of setting are analysed. The results of conducted experimental treatment of details are rotined.

## Взаємодія вітрових потоків з огороджувальними конструкціями висотних будівель

This article describes the formula determining the temperature, velocity and force of wind flow around the buildings. The dependence of wind speed and temperature difference, showing the distribution of aerodynamic coefficients on the facade of the building in different directions of wind flow. The basic building envelope and the effect of surface roughness on the flow around buildings.

## Modeling Technological Support the Process of Grinding Abrasive About

Consider the impact of technological regimes polishing surface finish and establish the optimal conditions for grinding and abrasive wheels revision in view of their period of stability.