scholarly journals MEASURING THE STROKE OF CONE DISK SPRINGS IN POWER ACCUMULATORS OF THE TURBOGENERATOR STATOR CORE USING A CAPACITIVE SENSOR

2018 ◽  
Vol 9 (2) ◽  
pp. 121-129 ◽  
Author(s):  
A. S. Levytskyi ◽  
I. O. Zaitsev ◽  
K. O. Kobzar
Keyword(s):  
Analytical Calculation ◽  
Capacitive Sensor ◽  
Response Characteristic ◽  
Calculation Model ◽  
High Potential ◽  
Stator Core ◽  
Response Characteristics ◽  
The Core ◽  
Electric Capacity ◽  
Coplanar Electrodes

The troubleproof and efficient work of powerful turbogenerators depends on the stability of their main mechanical parameters, which include the stator core pressing. The aim of the work was to describe the possibility of using a multielement capacitive sensor with coplanar electrodes to measure the movement of disk springs of the stabilizer systems power batteries in the turbogenerator stator core.The state of the core pressurizer can be indirectly assessed by measuring the displacement of the disk springs in power accumulators, which are installed on the tightening prism of the core instead of the compression nuts. To measure the movement of springs, a coplanar capacitive sensor with sectoral electrodes built into the power accumulators design is proposed. Each sector contains its own elementary sensor formed by coplanar electrodes. Each elementary sensor in each sector is placed on an annular dielectric plate and is formed by coplanar electrodes that are part of coaxial concentric rings. The sensor consists of a high-potential, low-potential and grounded electrodes. A grounded electrode is located between the high-potential and low-potential electrodes, as well as around them.A simplified analytical calculation model for obtaining the analytical response characteristic of the change in the informative component of the sensor electric capacity on the course of the disk springs in the CA is presented. The reliability of the model and the response characteristics are confirmed experimentally by testing a laboratory prototype of a capacitive sensor.

scholarly journals Method for Monitoring the Stator Core of a Powerful Turbo Generator

2021 ◽  
Vol 64 (4) ◽  
pp. 303-313
Author(s):  
A. S. Levitskyi ◽  
Ie. O Zaitsev ◽  
M. V. Panchik
Keyword(s):  
Automatic Measurement ◽  
Capacitive Sensor ◽  
Relative Displacement ◽  
Specific Pressure ◽  
Stator Core ◽  
Steel Sheets ◽  
The Core ◽  
Turbo Generator ◽  
Local Closure ◽  
Control Samples

The article is devoted to the development of an automatic method and device for monitoring the pressing of the stator core of a powerful turbo generator during its assembling at the manufacturer. The core is assembled and pressed in an upright position in separate parts; at each stage, it is necessary to monitor places with weakened solidity. The unevenness of the compaction density causes a relative displacement of the active steel sheets and losses of iron, as well as the appearance and development of certain defects (loosening of the teeth of the extreme packages, coloring of fragments of the active steel sheets, local closure of the sheets and heating of the packages), which can eventually cause severe accidents and failure of the turbo generator. Existing methods, including automatic ones, do not allow performing reliable monitoring. The method proposed by the authors for detecting places with weakened solidity is based on automatic measurement of the specific pressure of pressing during deformation of special control samples. A device for its implementation has been developed, which is a ring installed on the end surface of the core. Cells with control samples are evenly placed in the ring. The largest decrease in the sample thickness caused by the highest specific pressure corresponds to the smallest defect, and vice versa. As a pressure converter, it is proposed to use a flat metal membrane and a capacitive sensor with a digital output. The characteristics of the converter were calculated and experimentally verified. The specific pressure measurement results were processed using a special electronic unit. The device that has been developed makes it possible to improve labor productivity when monitoring the core, diagnose defects with greater reliability and eliminate them, and, ultimately, increase the reliability of the turbo generator as well as its durability.

scholarly journals Numerical calculation and experimental study on response characteristics of pneumatic solenoid valves

2019 ◽  
Vol 52 (9-10) ◽  
pp. 1382-1393 ◽  
Author(s):  
Xiang Zhang ◽  
Yonghua Lu ◽  
Yang Li ◽  
Chi Zhang ◽  
Rui Wang
Keyword(s):  
Switching Time ◽  
Response Characteristic ◽  
Test System ◽  
Solenoid Valve ◽  
Circuit Model ◽  
Inlet Pressure ◽  
Driving Voltage ◽  
Response Characteristics ◽  
Aerodynamic Model ◽  
Set Up

In order to analyze the response characteristics of the solenoid valve in depth, the flow field of the solenoid valve is analyzed by means of the computational fluid dynamics, and the aerodynamic parameters that are difficult to be obtained by the traditional methods are obtained with software FLUENT. We also set up the mathematical model of the solenoid valve, including the aerodynamic model, the circuit model, the magnetic circuit model and the mechanical motion model. The calculation is completed in the Simulink, and the results of the calculation are analyzed. A set of the solenoid valve response characteristic test system is built, and the response characteristic parameters such as response time and maximum action frequency of the solenoid valve are tested. The experimental results are verified by comparing them with the simulation results. The final result shows that the response characteristics are basically irrelevant to the action frequency at a suitable working frequency. The open switching time of the solenoid valve decreases with the increase in the inlet pressure and the driving voltage and increases with the increase in the number of coil turns. The close switching time increases with the increase in the inlet pressure, the driving voltage and the number of coil turns.

scholarly journals Study on the sensitivity of the hydraulic response characteristics of the electronic fuel injector regarding the key structural parameters

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401882259 ◽  
Author(s):  
Yaonan Feng ◽  
Jie Wang ◽  
Fukang Ma ◽  
Tiexiong Su ◽  
Chunlong Xu ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Influencing Factor ◽  
Response Characteristic ◽  
Fuel Injector ◽  
Closing Time ◽  
Range Analysis ◽  
Small Opening ◽  
Response Characteristics ◽  
And Control ◽  
Hydraulic Response

The sensitivity of key structural parameters to the hydraulic response characteristics in an electronic fuel injector is investigated. First, the hydraulic response characteristic is defined in detail (the opening/closing delay and the opening/closing time). Second, the key structural parameters influencing the hydraulic response characteristics are derived. Finally, the importance and effects of key structural parameters on hydraulic response characteristics are examined, by using the design of experiments method and the range analysis. Results show that the fuel inlet passage diameter is the primary influencing factor to the opening delay and closing delay, while the control piston diameter has the dominant effect on opening time and closing time. A small opening delay and a small opening time prefer a little fuel inlet passage diameter and control piston diameter; however, they contribute to a large closing time and closing delay. The fuel outlet passage diameter is the secondary influencing factor in opening delay, but the second factor that affects the opening time is the diameter of needle.

Responses of neurons in and near the thalamic ventrobasal complex of the rat to stimulation of uterus, cervix, vagina, colon, and skin

1993 ◽  
Vol 69 (2) ◽  
pp. 557-568 ◽  
Author(s):  
K. J. Berkley ◽  
G. Guilbaud ◽  
J. M. Benoist ◽  
M. Gautron
Keyword(s):  
Receptive Fields ◽  
The Body ◽  
Female Rats ◽  
Caudal Part ◽  
Response Characteristics ◽  
The Core ◽  
Ventrobasal Complex ◽  
Gentle Pressure ◽  
Somatic Receptive Fields ◽  
Stimulation Of

1. Previous studies in the rat and other species have shown that neurons in and near the ventrobasal complex (VB) can be activated by various visceral as well as somatic stimuli. 2. This study examined the responses of 84 single neurons in and near the rostral 2/3 of VB in 19 adult female rats in estrus to mechanical stimulation of the skin (brush, pressure, noxious pinch) and 4 different visceral stimuli, as follows: distension of both uterine horns, mechanical probing of the vagina, gentle pressure against the cervix, and distension of the colon. The rats were studied while under moderate gaseous anesthesia (33% O2-67% N2O + 0.5% halothane) and paralyzed (pancuronium bromide). 3. Of 77 neurons tested with both somatic and visceral stimuli, 70 were responsive to one type and/or the other. Responses to somatic stimuli were immediate with brief afterdischarges to the pinch stimuli. In contrast, responses to visceral stimuli were delayed an average of 9 s with long afterdischarges averaging 2 min. Most viscerally responsive neurons (74%) had somatic receptive fields, often (44%) to noxious pinch. 4. Of the 70 responsive neurons, 43 (61%) responded to 1 or more of the 4 visceral stimuli, primarily with excitation. Most of these 43 neurons (71%) were responsive to uterine distension, whereas fewer responded to stimulation of the cervix (45%), vagina (29%), or colon (34%). 5. Viscerally responsive neurons were preferentially located in regions bordering or near VB. Only 6 of 22 neurons within the core of VB (27%) responded to visceral stimuli, in contrast with 37 of 48 neurons bordering or near VB (77%). 6. The six viscerally responsive neurons within VB all had somatic receptive fields located primarily on the caudal part of the body and were responsive to only one or two of the four visceral stimuli, usually the uterus. The 37 viscerally responsive neurons bordering or near VB were of 3 types. Neurons of the first type (n = 15) were scattered throughout the areas bordering VB and responded to both somatic and visceral stimuli much like VB neurons, except that they showed more visceral convergence. Neurons of the second type (n = 11) were concentrated at the rostral and dorsal borders of VB and responded only to visceral stimuli, mainly the uterus. Neurons of the third type (n = 11) were concentrated ventrally and had very complex, long-lasting and history-dependent response characteristics to both visceral and somatic stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals An analytical model to determine the impact force of drone strikes

2021 ◽  
Author(s):  
Florian Franke ◽  
Michael Schwab ◽  
Uli Burger ◽  
Christian Hühne
Keyword(s):  
Load Distribution ◽  
Impact Force ◽  
Analytical Calculation ◽  
Calculation Model ◽  
Material Behavior ◽  
Major Influence ◽  
Impact Model ◽  
Simulation Data ◽  
Input Parameters ◽  
The Impact

AbstractIn addition to the well-known threats of bird and hail strikes, small unmanned aerial vehicles (sUAV) pose a new threat to manned aviation. Determining the severity of collisions between sUAVs and aircraft structures is essential for the safe use and integration of drones in airspace. A generic analytical calculation model needs to be developed to supplement the existing test and simulation data. This paper presents an analytic model for drone collisions with perpendicular and inclined targets. The targets have a rigid or elastic material behavior. The aircraft impact model, which is used for the design of nuclear reactor structures, is transferred and adjusted for sUAV impacts to calculate the impact force. A mass- and a burst load distribution are needed as input parameters. Both distributions are determined for an sUAV design depending on the flight direction. Compared to previous calculations, the new approach is to consider a moving target structure, which produces more realistic results. We compare the calculation results with simulation data from sUAV collisions with a commercial airliner windshield from the literature. The calculations show plausible results and a good agreement with literature data. Subsequently, the influence of the input parameters on the impact force is investigated. We see that spring stiffness, target mass, burst load distribution and damping have minor influence on the overall impact force. The impact velocity, mass distribution and flight orientation on the other hand have a major influence on the impact force. Further tests are needed to validate the impact model.

scholarly journals CONTACTLESS CAPACITIVE SENSOR OF THE SYSTEM FOR MONITORING THE PARAMETERS OF THE BEATING OF THE POWERFUL ELECTRICAL MACHINES SHAFTS

2020 ◽  
Vol 2020 (57) ◽  
pp. 81-88
Author(s):  
V.O. Bereznychenko ◽  
◽  
I.O. Zaitsev ◽  
Keyword(s):  
Measuring Transducer ◽  
Capacitive Sensor ◽  
Response Characteristic ◽  
Guard Ring ◽  
Element Analysis ◽  
Modeling Tools ◽  
Potential Electrode ◽  
General Plane ◽  
Change Response ◽  
The Impact

In this paper presents the results of the definition the need to use a Kelvin guard ring to reduce the impact of external fields and non-uniformity of equipotential lines to change response characteristic of the capacitive sensor with a central high-potential electrode and a Kelvin guard ring. Measuring transducer placing in the immediate vicinity of the electrodes of the sensor, which eliminates the need to use a triaxial cable, was proposed. The sensor is designed to measure powerful generators shafts cylindrical surfaces parameters run-out. Capacitive sensor response characteristic function which depending on distance between the general plane of electrodes of the sensor and the grounded surface of a shaft is determined analytically and by computer simulation methods. The expediency of using computer modeling tools by finite element analysis methods for studying the metrological characteristics of sensors was shown. References 21, figures 4, table 1.

Study on the Dynamic Characteristics of Hot-Film Flow Sensor Based on the Sampling Air Channel

2014 ◽  
Vol 494-495 ◽  
pp. 197-200 ◽  
Author(s):  
Wei Liu ◽  
Li Feng Zhao
Keyword(s):  
Dynamic Response ◽  
Film Flow ◽  
Coupling Model ◽  
Response Characteristic ◽  
Flow Sensor ◽  
Intake Manifold ◽  
Film Sensor ◽  
Response Characteristics ◽  
Dynamic Response Characteristics ◽  
Hot Film

The hot-film flow sensors accurately measure the intake flow of engine. The air flow in the engine intake manifold is typical unsteady flow whose flow velocity changes remarkably. Therefore, the flow sensor should have a faster dynamic response characteristic. A thermosetting coupling model of a hot-film sensor was established based on CFD which is used to simulate dynamic response characteristics; the temperature field of the hot-film flow sensor probe was simulated. In addition, the dynamic response characteristics of the sensor simulated using the step pulse, and tested the dynamic response characteristics based on flow test equipment.

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