scholarly journals Numerical method for identifying the flow model in the line pipe

2020 ◽  
Vol 4 (2) ◽  
pp. 138-148
Author(s):  
Vladimir V. Zholobov ◽  
Keyword(s):  
Experimental Data ◽  
Drag Coefficient ◽  
Pressure Measurement ◽  
Dynamic Control ◽  
Measurement Data ◽  
Computing System ◽  
Structural Relationship ◽  
Hydraulic Drag ◽  
Technical Literature ◽  
Line Pipe

With high availability of measuring tools and wide opportunities of modern computer technology, the existing methods of predictive estimations of hydraulic parameters for the fluids’ pipeline transport seem to be too approximate. Due to this, it is relevant to adapt the most accurate relationships available in the scientific and technical literature to real conditions. Based on the review of analytical solutions for calculating friction losses in the pressure lines, the structure of relationships most accurately reflecting the experimental data of I. Nikuradze is determined, where the hydraulic drag coefficient ? is described by the piecewise-continuous relations, given by O. M. Ayvazyan. The hydraulic drag coefficient structural relationship shall be selected with the highest capability to summarize the experimental data available in the scientific and technical literature. Using the pressure measurement data, free parameters included in the selected relationship for the hydraulic drag coefficient shall be identified. The numerical computation algorithm is proposed that enables to recover the values of parameters in the structural relationship of hydraulic drag coefficient ? through multiple application of the well-known method of sensitivity functions and pressure measurement data in the line pipe. The procedure is described for generating the computing system of ordinary differential equations that enables for every fixed set of experimental data (pressure and flow rate) to determine (or correct, if necessary) the corresponding parameters in the unified structural relationship for hydraulic drag coefficient ?. The feature of the proposed algorithm is the absence of embedded cycles. Dynamic control of variable parameters in the hydraulic drag coefficient ? based upon the proposed approach enables to improve the predictive estimations accuracy of flow parameters while pumping fluids and to acquire additional data on the state of the fluids filling the inner pipeline space.

scholarly journals Material parameter identification using finite elements with time-adaptive higher-order time integration and experimental full-field strain information

2021 ◽  
Author(s):  
Stefan Hartmann ◽  
Rose Rogin Gilbert
Keyword(s):  
Experimental Data ◽  
Finite Elements ◽  
Parameter Identification ◽  
Material Parameter ◽  
Measurement Data ◽  
Least Square ◽  
Image Correlation ◽  
Field Strain ◽  
Material Parameter Identification ◽  
Full Field

AbstractIn this article, we follow a thorough matrix presentation of material parameter identification using a least-square approach, where the model is given by non-linear finite elements, and the experimental data is provided by both force data as well as full-field strain measurement data based on digital image correlation. First, the rigorous concept of semi-discretization for the direct problem is chosen, where—in the first step—the spatial discretization yields a large system of differential-algebraic equation (DAE-system). This is solved using a time-adaptive, high-order, singly diagonally-implicit Runge–Kutta method. Second, to study the fully analytical versus fully numerical determination of the sensitivities, required in a gradient-based optimization scheme, the force determination using the Lagrange-multiplier method and the strain computation must be provided explicitly. The consideration of the strains is necessary to circumvent the influence of rigid body motions occurring in the experimental data. This is done by applying an external strain determination tool which is based on the nodal displacements of the finite element program. Third, we apply the concept of local identifiability on the entire parameter identification procedure and show its influence on the choice of the parameters of the rate-type constitutive model. As a test example, a finite strain viscoelasticity model and biaxial tensile tests applied to a rubber-like material are chosen.

Analysis of Operating Deflection Shapes Based on Subspace Method

1997 ◽  
Author(s):  
Nobutaka Tsujiuchi ◽  
Yuichi Matsumura ◽  
Takayuki Koizumi
Keyword(s):  
Experimental Data ◽  
Time Domain ◽  
State Space Model ◽  
Measurement Data ◽  
Time Varying ◽  
Subspace Method ◽  
Identification Scheme ◽  
Space Model ◽  
Time Varying Systems ◽  
Frequency Components

Abstract In this paper, we propose the new method to identify the Operating Deflection Shapes (ODSs) from the measurement data of time domain. At first, we present the identification scheme of ODSs based on a state-space model. Then the scheme is extended to identify the ODSs adaptively for the time-varying systems by using the URV Decomposition (URVD). Proposed scheme is able to decompose the deformation of a structure under operating condition into the underlying superposition of well excited frequency components. This paper introduces the algorithm and shows the effectiveness of our proposed scheme applyed for both synthesized and experimental data.

scholarly journals Evaluation of the Accuracy of the Delta Life DL 1000 Oscillometric Monitor for Blood Pressure Measurement in Anesthetized Dogs of Different Weight Ranges

2020 ◽  
Vol 48 ◽  
Author(s):  
Bárbara Silva Correia ◽  
Eduardo Raposo Monteiro ◽  
João Victor Barbieri Ferronatto ◽  
Luciana Branquinho Queiroga ◽  
José Ricardo Herrera Becerra
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Pressure Measurement ◽  
Elective Surgery ◽  
Blood Pressure Measurement ◽  
Measurement Data ◽  
Arterial Blood ◽  
Anesthetized Dogs ◽  
Group 2 ◽  
Group 1

Background: Arterial blood pressure is one of the most commonly variables monitored during anesthetic procedures in veterinary patients. The most reliable method for measuring arterial blood pressure in dogs and cats is the direct (invasive) method. However, the oscillometric method is less complex and more practical for clinical routine in small animals. Nevertheless, oscillometric monitors present great variability in accuracy. The present study aimed to determine the accuracy of the Delta Life DL 1000 oscillometric monitor for measurement of systolic, mean and diastolic blood pressures (SAP, MAP and DAP, respectively) in anesthetized dogs of different weight ranges.Materials, Methods & Results: This study was approved by the Institutional Ethics Committee of Animal Use. Fifteen female dogs of different breeds, weighing 11.6 ± 10.0 kg and with a mean age of 48 ± 51 months were used. All animals were scheduled for elective surgery under general anesthesia in the Institution Veterinary Hospital. Dogs were anesthetized with morphine, propofol and isoflurane and had one 20 or 22 gauge catheter introduced into the dorsal pedal artery for continuous, invasive monitoring of SAP, MAP and DAP. A blood pressure cuff was positioned over the middle third of the radius and connected to Delta Life DL 1000 monitor. Oscillometric readings of SAP, MAP and DAP were registered every 5 minutes, and invasive values were simultaneously recorded. Values obtained with both methods were compared (invasive versus oscillometric) by use of the Bland Altman method to determine the bias, standard deviation of bias and 95% limits of agreement. The percentages of errors between the methods within 10 mmHg and within 20 mmHg were calculated. The results obtained were compared with the criteria from the American College of Veterinary Internal Medicine (ACVIM) for validation of indirect methods of arterial blood pressure measurement. Data were stratified into two groups according to the weight: < 10 kg (Group 1; n = 9); and ≥ 10 kg (Group 2; n = 6). In Group 1, 119 paired measurements were obtained, four of which classified as hypotension (SAP < 90 mmHg), 98 as normotension (SAP from 90 to 140mmHg) and 17 as hypertension (SAP > 140 mmHg). Bias (± SD) values in Group 1 were as follows: SAP, 5.2 ± 18.1 mmHg; MAP, -3.4 ± 17.2 mmHg; and DAP, 12.0 ± 17.5 mmHg. The percentages of errors within 10 mmHg were 40.3% for SAP; 45.4% for MAP and 28.6% for DAP. The percentages of errors within 20 mmHg were 72.3% for SAP, 84.0% for MAP and 68.1% for DAP. In Group 2, 66 paired measurements were obtained, nine of which classified as hypotension, 56 as normotension and one as hypertension. Bias (± SD) in Group 2 were as follows: SAP, 13.6 ± 14.3 mmHg; MAP, -1.1 ± 13.5 mmHg; and DAP, 8.2 ± 16.0 mmHg. The percentages of errors within 10 mmHg were 33.3% for SAP, 77.3% for MAP and 33.3% for DAP. The percentages of errors within 20 mmHg were 65.1% for SAP, 92.4% for MAP and 83.4% for DAP.Discussion: Based on the results of this study and reference criteria from the ACVIM, the Delta Life DL 1000 monitor had a poor accuracy for SAP, MAP and DAP and did not meet the criteria from the ACVIM in anesthetized dogs under 10 kg. Measurements of MAP in dogs ≥ 10 kg met the ACVIM criteria, but measurements of SAP and DAP did not. Based on the findings in this study, the DL 1000 oscillometric monitor is not recommended for blood pressure measurement in anesthetized dogs < 10 kg. In dogs ≥ 10 kg, measurements of MAP yielded acceptable values, but SAP and DAP measurements did not.

scholarly journals Mechatronic Device for Locomotor Training

2016 ◽  
Vol 10 (4) ◽  
pp. 310-315 ◽  
Author(s):  
Sławomir Duda ◽  
Damian Gąsiorek ◽  
Grzegorz Gembalczyk ◽  
Sławomir Kciuk ◽  
Arkadiusz Mężyk
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Measurement Data ◽  
Healthy Person ◽  
Control Algorithms ◽  
Design Team ◽  
Locomotor Training ◽  
Interdisciplinary Design ◽  
Machine Control ◽  
Simulation Results

Abstract This paper presents a novel mechatronic device to support a gait reeducation process. The conceptual works were done by the interdisciplinary design team. This collaboration allowed to perform a device that would connect the current findings in the fields of biomechanics and mechatronics. In the first part of the article shown a construction of the device which is based on the structure of an overhead travelling crane. The rest of the article contains the issues related to machine control system. In the prototype, the control of drive system is conducted by means of two RT-DAC4/PCI real time cards connected with a signal conditioning interface. Authors present the developed control algorithms and optimization process of the controller settings values. The summary contains a comparison of some numerical simulation results and experimental data from the sensors mounted on the device. The measurement data were obtained during the gait of a healthy person.

Dynamic Control of Computation Consistency in the Parallel Dataflow Computing System

2021 ◽  
Vol 27 (12) ◽  
pp. 625-633
Author(s):  
N. N. Levchenko ◽  
◽  
D. N. Zmejev ◽  
Keyword(s):  
Computational Model ◽  
High Performance ◽  
Dynamic Control ◽  
Computing System ◽  
Computational Process ◽  
Computing Systems ◽  
Systems Software ◽  
Dataflow Computing

When developing high-performance multiprocessor computing systems, much attention is paid to ensuring uninterrupted operation, both in terms of hardware and software. In traditional computing systems, software is the main focus in address­ing these issues. The article discusses the solution to the issue of ensuring uninterrupted operation for the parallel dataflow computing system (PDCS), which implements the dataflow computational model with a dynamically formed context. Due to the features of the PDCS, it is proposed to implement this type of control in hardware, which will increase its efficiency, since the computational process will be controlled in dynamics, and not only in statics.

Calculus of the Relationship of the Cutting Moment at Drilling of the Stainless Steel X15CrNiSi20-12

2015 ◽  
Vol 760 ◽  
pp. 469-474 ◽  
Author(s):  
Aurelian Vlase ◽  
Ovidiu Blăjină ◽  
Marius Iacob
Keyword(s):  
Experimental Data ◽  
Stainless Steel ◽  
Mathematical Software ◽  
Technical Literature ◽  
Technical Research ◽  
Analytic Relationship ◽  
Subsequent Processing ◽  
Manufacturing Activity ◽  
Relationship Of ◽  
The Relationship

This paper studies the cutting moment at drilling of the stainless steel X15CrNiSi20-12. The structure of the cutting moment relation was modified with respect to the relation available in the technical literature for common steels. The tool speed was included in the calculus relation. The experimental data and their subsequent processing represent the original contributions of the authors to the estimation of polytropic exponents and to the assessment in terms of structure of the calculus relation of the cutting moment. The paper also contains graphs for the variation of the cutting moment with parameters of the cutting technology. The graphs are drawn based on the analytic relationship of the cutting moment, obtained in the paper, using the mathematical softwareMaple. The results presented in this study can be taken into consideration in the educational studies and in the theoretical technical research. Also, they can be readily implemented in the manufacturing activity. Our further studies aim these problems for another steels classes.

Dynamic Flexoelectric Actuation and Vibration Control of Beams

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Mu Fan ◽  
Bolei Deng ◽  
Hornsen Tzou
Keyword(s):  
Experimental Data ◽  
Dynamic Control ◽  
Longitudinal Direction ◽  
Bottom Surface ◽  
Internal Stresses ◽  
Control Effect ◽  
Flexoelectric Effect ◽  
Control Moment ◽  
Fixed End ◽  
And Control

A flexoelectric cantilever beam actuated by the converse flexoelectric effect is evaluated and its analytical and experimental data are compared in this study. A line-electrode on the top beam surface and a bottom surface electrode are used to generate an electric field gradient in the beam, so that internal stresses can be induced and applied to distributed actuations. The dynamic control effectiveness of the beam is investigated with a mathematical model and is validated by laboratory experiments. Analyses show that the actuation stress induced by the converse flexoelectric effect is in the longitudinal direction and results in a bending control moment to the flexoelectric beam since the stress in the thickness is inhomogeneous. It is found that thinner line-electrode radius and thinner flexoelectric beam lead to larger control effects on the beam. The position of the line-electrode on the top surface of the beam also influences the control effect. When the line-electrode is close to the fixed end, it induces a larger tip displacement than that is close to the free end. Analytical results agree well with laboratory experimental data. This study of flexoelectric actuation and control provides a fundamental understanding of flexoelectric actuation mechanisms.

Study on the Minimum Drag Coefficient Phenomenon of Supercritical Pressure Water in the Pseudocritical Region

2012 ◽  
Author(s):  
Xianliang Lei ◽  
Huixiong Li ◽  
Shuiqing Yu ◽  
Yifan Zhang ◽  
Tingkuan Chen
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Drag Coefficient ◽  
Supercritical Pressure ◽  
Pressure Drops ◽  
Minimum Drag ◽  
Wide Range ◽  
Pressure Water ◽  
Isothermal Flows ◽  
Supercritical Pressure Water

With the development of supercritical (and even ultra-supercritical) pressure boilers (SCBs) with high capacities, and at the same time, with the consideration of supercritical pressure water-cooled reactors (SCWRs) as one of the six most promising reactor concepts accepted in the Generation IV International Forum (GIF), flow and heat transfer of supercritical water becomes more and more important for both the design and operation safety of the related facilities. Thermo-hydraulic characteristics are among the issues, which are of special significance for the SCBs and SCWRs. It has been found that at supercritical pressures, the hydraulic resistance of water exhibits special characteristics in regions near its pseudo-critical point, which is hereafter called the minimum drag coefficient phenomenon. Experimental investigation was carried out in the present study to investigate further the characteristics of drag coefficient of supercritical pressure water under different conditions. The total pressure drop characteristic of water flowing in smooth tube and internally ribbed tube under the supercritical pressures was measured in experiments with a wide range of operational parameters, such as the system pressures ranging from 23 to 28 MPa, the average heat fluxes varied from 100 kW/m2 to 500kW/m2, and the mass fluxes of water in a range of 600 ∼ 1050 kg/m2s. The experimental data were compared with prediction results calculated by existing common correlations for single phase pressure drops, and large discrepancies were observed between the experimental data and the prediction results. Furthermore, the pressure drops characteristics of supercritical pressure water in cases with different tube arrangement and test conditions were compared with each other, such as that in horizontal tubes and vertical tubes, and that in isothermal flows and in non-isothermal flows. Additionally, this phenomenon observed in the present studies was also analyzed by using computational fluid dynamics technology, and the mechanism of pressure drop variation was reasonably explained. It was found that the deviation appeared between the previously proposed drag coefficient correlations and the present experimental data was mainly owning to ignoring the variation of an existence of the minimum drag coefficient in the pseudo critical region in previous studies, and based on the data obtained in this study, a new correlation for drag coefficient for supercritical pressure water was presented.

Experimental Study of the Vertical Hydraulic Drag Force on Regular Tetrahedron

2013 ◽  
Vol 860-863 ◽  
pp. 1547-1550
Author(s):  
Rui Le ◽  
Wei Jiang ◽  
Qi Liu ◽  
Nan Chang Sun ◽  
Bing Xu
Keyword(s):  
Experimental Study ◽  
Drag Coefficient ◽  
Drag Force ◽  
Vertical Velocity ◽  
Hydraulic Engineering ◽  
Hydraulic Drag ◽  
Regular Tetrahedron ◽  
Impact Effect ◽  
Drag Forces ◽  
The Impact

It is well known that the hydraulic drag force on objects cant be ignored in computing the movement of objects in water. And the drag forces on sphere and cuboids have long been studied. While in hydraulic engineering, objects with regular tetrahedron shape are widely used to form the foundation and temporary dam for they can interlock each other to obtain a compacted integral. In this article the vertical hydraulic drag force on regular tetrahedron is studied by indoor experiments, the relation of the vertical hydraulic drag coefficient and the vertical velocity is proposed. And the max vertical speeds of different materials are deduced. The result is helpful to compute the movement of regular tetrahedron in water and estimate the impact effect on the groundwork.

Research Regarding the Relationship of the Axial Cutting Force at Drilling of the Stainless Steel X15CrNiSi20-12

2014 ◽  
Vol 657 ◽  
pp. 3-7
Author(s):  
Ovidiu Blăjină ◽  
Vlad Darie ◽  
Aurelian Vlase ◽  
Marius Iacob
Keyword(s):  
Experimental Data ◽  
Stainless Steel ◽  
Cutting Force ◽  
Mathematical Software ◽  
Technical Literature ◽  
Technical Research ◽  
Force Relation ◽  
Manufacturing Activity ◽  
Relationship Of ◽  
The Relationship

This paper studies the cutting force at drilling of the stainless steel X15CrNiSi20-12. The structure of the cutting force relation was modified with respect to the relation available in the technical literature for common steels. The tool speed was included in the calculus relation. The experimental data and their subsequent processing represent the original contributions of the authors to the estimation of polytropic exponents and to the assessment in terms of structure of the calculus relation of the cutting force. The paper also contains graphs for the variation of the cutting force with parameters of the cutting technology. The graphs are drawn based on the analytic relationship of the cutting force, obtained in the paper, using the mathematical softwareMaple. The results presented in this study can be taken into consideration in the educational studies and in the theoretical technical research. Also, they can be readily implemented in the manufacturing activity. Our further studies aim these problems for another steels classes.

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