Design of a system for fastening the pipelines’ elements to be brazed of an automated gas metering unit

The article discusses an automated measuring installation, and also analyzes the subject area. Some types of soldering are considered (capillary, diffusion, contact-reaction and others). The choice of induction brazing for the soldering of pipeline elements of an automated gas metering installation has been substantiated. The work presents the installation of induction heating, considering the required technological parameters. Based on this installation, the basic diagram of the Fitting and the schematic diagram of the connecting sleeve were corrected, which will allow the development of a mobile induction installation as well as collapsible inductors. Potential induction equipment and the developed designs can be used to connect pipelines in the oil and gas industry.

Analysis of centrifugal compressor testing capabilities

The work shows examining of the centrifugal compressor for which there are no technical conditions by which the compressor manufacturer defines the form and important characteristics of the measuring installation. In the absence of the necessary data, a table for testing of centrifugal compressors was designed, where the pipeline measures and other details are freely defined in accordance with the available possibilities.

Modern approach to testing and validation of driver assistance systems

The ever-increasing demands of vehicle safety are forcing vehicle manufacturers to develop ADAS systems (intelligent assistants). However, before starting sales of vehicle equipped with such functions it is necessary to fully test and validate the algorithms for the operation of electronic sys-tems in various conditions. Nowadays, the most popular methods for debugging and testing ADAS systems are based on model-, software- and hardware-in-the-loop simulation, which allows devel-opers to identify and eliminate errors in the early stages of product development, thus saving mon-ey. Despite the enormous advantages of simulation, full-scale tests remain the fundamental and final stage before the start of mass production. This is due to the fact that international and Russian government standards currently don’t provide the certification of electronic assistants through virtu-al tests. In this regard, manufacturers of measuring equipment and engineers face the task of devel-oping a new test setup that provides fixing the GNSS-position of vehicles in dynamic modes with centimeter accuracy, as well as making synchronized video recording. This article describes the ap-proach of the employees of the Nizhny Novgorod State Technical University n.a. R.E. Alekseev to the solution of this problem: the design of the concept and its implementation on a light commercial vehicle with ADAS systems. To fix coordinates with centimeter accuracy we have used Racelogic Vbox 100 Hz, operating in the RTK-mode, synchronized video recording was made using Racelogic Video Vbox Pro, which includes 4 wide-angle cameras. The approbation of the measuring installation was carried out during testing the following systems: a blind spot detector, a lane departure warning and a parking space search assistant. The article presents a number of graphs of the functioning of one of the systems.

Determination of the Friction Angle between the Wheat Ear and Stripper Fingers

Introduction. Determining the angle of friction between stripper fingers and a wheat ear is an important task aimed at finding the optimal design parameters and operating modes of stripping devices. When stripper fingers and wheat ears interact, the relative position of the ear glumes, flower glumes, and grains is densified. In this case, the spikelet surface roughness changes. Materials and Methods. A series of experiments was carried out to determine the angles of friction between a steel stripper fingers and wheat ears. Wheat varieties “Moskovskaya 40” and “Moskovskaya 56” were selected for the study. The experimental measuring installation is a frame with a rotatable platform mounted on it with the adjustable angle of rotation. The goniometer head provides the ability to fix the platform rotation angle value. The weight suspended from the stem of the plant imitated the forces arising in the process of stripping. The width and thickness of the wheat ear were also measured and recorded. Results. The influence of the size of the wheat ear on the angle of friction is determined. The results of the study are divided into two groups. The following values of the friction angles were obtained: 26.4–31.5° for the wheat with ear width of less than 10.4 mm; 22.0–27.1° for the wheat with ear width of more than 10.4 mm. Discussion and Conclusion. The angles of friction of wheat ears on the stripper fingers for wheat varieties specific to the Central region are obtained. The dependence of the angle of friction on the ratio of the geometric dimensions of the wheat ear and the slit width of the stripper fingers is established. When a wheat ear width is less than 10.4 mm, an effect of pinching the spikelets between the stripper fingers was observed. In this case, the coefficient of friction noticeably increased.

MEASURING INSTALLATION FOR DETERMINING CURRENT-VOLTAGE CHARACTERISTICS OF COMPOSITE SUPERCONDUCTORS IN THE PRODUCTION OF CRYOGENIC TECHNIQUE

The method and measuring installation for determining the actual critical current values in superconductors, at helium temperatures, coming to the market from domestic and foreign manufacturers of composite wire, round or rectangular section, based on the Nb-Ti alloy, are considered.

SIMULATION OF ELECTRICAL MONITORING OF DAMS WITH LEAKAGE WITH A TRANSVERSE PLACEMENT OF THE MEASURING INSTALLATION

Numerical modeling of the problem of dam monitoring by the Electrical Resistivity Tomography method is carried out. The mathematical model is based on integral equations with a partial Fourier transform with respect to one spatial variable. It is assumed that the measurement line is located across the dam longitude. To approximate the shape of the dam surface, the Radial Basic Functions method is applied. The influence of locations of the water-dam, dam-basement, basement-leakage boundaries with respect to the sounding installation, which is partially placed under the headwater, is studied. Numerical modeling is carried out for the following varied parameters: 1) water level at the headwater; 2) the height of the leak; 3) the depth of the leak; 4) position of the supply electrode; 5) water level and leaks positions are changing simultaneously. Modeling results are presented in the form of apparent resistivity curves, as it is customary in geophysical practice.

Acoustic impedance of orifices with grazing flow

The paper presents an overview of the results of studies of acoustic impedance of orifices with grazing airflow. Empirical models of orifice impedance, which take into account the grazing flow, and the existing methods of measuring the acoustic impedance of orifices and the experimental setup created for this purpose are analyzed. A simpler way of measuring the acoustic characteristics of an orifice with grazing flow is considered. The scheme of the developed measuring installation and its general appearance are given.

Reducing the measurement error of signal propagation delays using an optical reflectometer with picosecond resolution

The problems requiring high-precision measurements of signal propagation delays in optical fibers are considered. Design features of a pulsed optical reflectometer with a picosecond resolution designed for measuring propagation delays of a signal are considered. It is shown that the error of such a reflectometer includes the additive and multiplicative components. A method for determining the additive component of the optical reflectometer error based on measurements of signal delays introduced by individual optical fiber coils and the total delay introduced by series-connected coils is proposed. The requirements to the measurement conditions are formulated and the results of the error estimation of the proposed method are presented. To exclude the multiplicative component of the reflectometer error, a method for determining corrections to the reflectometer readings is proposed. The method is based on measuring the propagation delays of the signal in the coils of the optical fiber, first using reference equipment (installation for measuring the propagation delay of the signal), and then using an optical reflectometer, and then calculating the differences of the obtained measurement results. The scheme of installation for measurements of a propagation delay of signal in a coil of optical fiber is presented, the principle of operation of measuring installation is described. The results of the estimation of the error in determining the corrections to the reflectometer readings by the proposed method are presented. It is shown that the exclusion of the additive and multiplicative components of the error will reduce the error of optical reflectometers to values less than ± 100 ps.

Hydrodynamic Surface Evaluation of a Polymeric Reverse Osmosis Membrane Using a Crossflow Cell

The purpose of this research was to visualize the fouling process of a flat-sheet polymeric membrane into a flow cell, using particles to study their deposition onto the membrane surface. This set of experiments was analyzed from an imagistic point of view, designing for this purpose a measuring installation where hydrodynamic surface evaluation was carried out with an image processing concerning to the reverse osmosis operation. To ensure the measurements accuracy, calculations, logical approximation, and comparisons were made with existing and verified models, revealing that the differences were insignificant.