scholarly journals Minimization of excess torque in multi-time deployment-folding hinge joints

2021 ◽  
Vol 5 (1) ◽  
pp. 35-43
Author(s):  
S. A. Zommer ◽  
S. I. Nemchaninov ◽  
A. P. Kravchunovsky ◽  
A. V. Ivanov ◽  
M. S. Rudenko
Keyword(s):  
Experimental Data ◽  
Computational Analysis ◽  
Mechanical Characteristics ◽  
Solar Array ◽  
Constant Force ◽  
Calculation Algorithm ◽  
Drive Force ◽  
Design Algorithms ◽  
Mechanical Devices ◽  
Angle Of Rotation

The paper presents a method for minimizing the torque value of the multi-time deploymentfolding hinges. The objects of research were the hinges assembly of multi-time deployment-folding mechanical devices of solar array, which are used as part of the platforms of spacecraft. A computational analysis of the forces and moments that act in the hinges in the process of their opening and folding is carried out. The minimization of the excessive torque value without changing the design and layout of the hinge is possible by changing the shape of the dependence of the spring drive force on the angle of rotation of the hinge. The possibility of using constant force springs as part of the hinge is considered, the existing design algorithms are improved and a program for calculating the geometric and mechanical characteristics of constant force springs is developed. Experimental data were obtained for measuring the forces of springs of various configurations, showing the dependence of the magnitude of the force on the magnitude of the spring deformation and confirming the efficiency of the proposed calculation algorithm. A prototype of a hinge assembly with a constant force spring drive was developed and manufactured. The possibility of minimizing the excess torque without the need to change the design of the hinge while maintaining its technical characteristics was experimentally confirmed.

scholarly journals DEVELOPMENT AND TESTING OF ALGORITHM FOR CALCULATION OF OPERATING PARAMETERS OF TRAWLING SYSTEMS

2019 ◽  
Vol 198 ◽  
pp. 221-229 ◽  
Author(s):  
E. A. Zakharov ◽  
O. N. Kruchinin ◽  
D. L. Shabelsky
Keyword(s):  
Experimental Data ◽  
Visual Basic ◽  
Educational Process ◽  
Resistance Force ◽  
Operating Parameters ◽  
Calculation Algorithm ◽  
Model Application ◽  
Bottom Trawling ◽  
Good Convergence ◽  
Expansion Force

Numerical model of trawling system is developed on the base of equilibrium principle, using F.I. Baranov’s scheme of its power and geometric parameters interdependence. The model application to bottom trawling takes into account the effect of bottom grounds on the resistance force and expansion force of the trawling system. Algorithm is proposed for calculation of operating parameters of bottom and midwater trawls, with an operation to minimize the error of iteration. The model and the calculation algorithm were tested in MS Office Excel environment, using Visual Basic programming, and showed good convergence of the calculated and experimental data that indicates reliability of the model. This algorithm and the program for calculation of operating parameters could be used for trawl designing, in accounting surveys to determine the trawl opening, and in educational process for training the industrial fishery scholars.

Two-Phase Flow Behavior in Channels With Sudden Area Change Using Experimental and Computational Approach

2017 ◽  
Author(s):  
Ashish Kotwal ◽  
Che-Hao Yang ◽  
Clement Tang
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Experimental Analysis ◽  
Single Phase ◽  
Computational Analysis ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Area Change

The current study shows computational and experimental analysis of multiphase flows (gas-liquid two-phase flow) in channels with sudden area change. Four test sections used for sudden contraction and expansion of area in experiments and computational analysis. These are 0.5–0.375, 0.5–0.315, 0.5–0.19, 0.5–0.14, inversely true for expansion channels. Liquid Flow rates ranging from 0.005 kg/s to 0.03 kg/s employed, while gas flow rates ranging from 0.00049 kg/s to 0.029 kg/s implemented. First, single-phase flow consists of only water, and second two-phase Nitrogen-Water mixture flow analyzed experimentally and computationally. For Single-phase flow, two mathematical models used for comparison: the two transport equations k-epsilon turbulence model (K-Epsilon), and the five transport equations Reynolds stress turbulence interaction model (RSM). A Eulerian-Eulerian multiphase approach and the RSM mathematical model developed for two-phase gas-liquid flows based on current experimental data. As area changes, the pressure drop observed, which is directly proportional to the Reynolds number. The computational analysis can show precise prediction and a good agreement with experimental data when area ratio and pressure differences are smaller for laminar and turbulent flows in circular geometries. During two-phase flows, the pressure drop generated shows reasonable dependence on void fraction parameter, regardless of numerical analysis and experimental analysis.

scholarly journals In-beam tests of a PET demonstrator (LAPD) for hadrontherapy beam ballistic control: data comparison to Geant4 Monte-Carlo predictions

2020 ◽  
Vol 225 ◽  
pp. 09005
Author(s):  
Sébastien Binet ◽  
Arthur Bongrand ◽  
Emmanuel Busato ◽  
Christophe Insa ◽  
Daniel Lambert ◽  
...  
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Mechanical Characteristics ◽  
Ion Beams ◽  
Cancer Treatments ◽  
Control Data ◽  
Data Comparison ◽  
Large Acceptance ◽  
Ballistic Control

This paper describes a small prototype of an in beam PET like detector, named ”Large Acceptance Pixelized Detector” (LAPD), developed to test technical concepts for the ion range control in the context of cancer treatments using proton or ion beams. The mechanical characteristics of this detector together with the read-out electronics are first presented. Then, results of a first experiment, performed on a 65 MeV proton beamline, are reported. Finally, we discuss the ability of Geant4 Monte-Carlo to reproduce the experimental data.

Energy Approach for Determine Frequency and Amplitude of Vibration of Piping With Closed Side Branches

2015 ◽  
Author(s):  
Igor Orynyak ◽  
Iaroslav Dubyk ◽  
Anatolii Batura
Keyword(s):  
Experimental Data ◽  
Boundary Conditions ◽  
Calculation Method ◽  
Acoustic Vibration ◽  
Energy Functional ◽  
Energy Approach ◽  
Calculation Algorithm ◽  
Local Excitation ◽  
Resonance Frequencies ◽  
System Energy

This article suggests calculation method for frequency and amplitude of acoustic vibration in piping with closed side branches, caused by gaseous running flow. The calculation algorithm consists of following steps: i) local excitation system is defined; ii) different combinations of boundary conditions are formed; iii) for fixed pair of boundary conditions ratio of stored in system energy and radiated from boundaries energy is written; iv) for every frequency energy functional is maximized to find boundary conditions; v) resonance frequencies are determined from plotting a curve of maximal energy ratio vs. frequency. Energy approach was further developed to analyze amplitude of vibration. For amplitude determine balance between injected energy (which depends on the Strouhal number and is defined from experimental data for laboratory geometries), and radiated from boundaries energy is written.

Research on Overloading Protection of Permanent Magnetic Coupler in Coal Mine

2014 ◽  
Vol 597 ◽  
pp. 492-497
Author(s):  
Wen Qi Yuan ◽  
Yue Liu ◽  
Dong Li ◽  
Guo Ying Meng
Keyword(s):  
Experimental Data ◽  
Mechanical Characteristic ◽  
Coal Mine ◽  
Mechanical Characteristics ◽  
Input Power ◽  
Maximum Torque ◽  
Characteristic Curves ◽  
Motor Torque ◽  
Output Torque

In this paper, with simulations and experiments analysed by the software of Ansoft Maxwell, research on overloading protection of permanent magnetic coupler in coal mine is carried out and the conclusive curves of mechanical characteristics are plotted through experimental data. The conclusion can be gained from mechanical characteristic curves: when the output value of torque reaches the maximum torque of magnetic coupler, the output torque and speed will drop along with increases of the slip, and the input power value of motor is less than the power value at the time when the motor torque value is at the maximum. It explains that the magnetic coupler has the function for overloading protection.

Three Dimensional Heat Transfer Analysis of High Pressure Turbine Blade

2009 ◽  
Author(s):  
A. Sipatov ◽  
L. Gomzikov ◽  
V. Latyshev ◽  
N. Gladysheva
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
High Pressure ◽  
Rotor Blade ◽  
Computational Analysis ◽  
Three Dimensional ◽  
Heat Transfer Analysis ◽  
Aircraft Engines ◽  
Turbine Stage ◽  
High Pressure Turbine

The present tendency of creating new aircraft engines with a higher level of fuel efficiency leads to the necessity to increase gas temperature at a high pressure turbine (HPT) inlet. To design such type of engines, the improvement of accuracy of the computational analysis is required. According to this the numerical analysis methods are constantly developing worldwide. The leading firms in designing aircraft engines carry out investigations in this field. However, this problem has not been resolved completely yet because there are many different factors affecting HPT blade heat conditions. In addition in some cases the numerical methods and approaches require tuning (for example to predict laminar-turbulent transition region or to describe the interaction of boundary layer and shock wave). In this work our advanced approach of blade heat condition numerical estimation based on the three-dimensional computational analysis is presented. The object of investigation is an advanced aircraft engine HPT first stage blade. The given analysis consists of two interrelated parts. The first part is a stator-rotor interaction modeling of the investigated turbine stage (unsteady approach). Solving this task we devoted much attention to modeling unsteady effects of stator-rotor interaction and to describing an influence of applied inlet boundary conditions on the blade heat conditions. In particular, to determine the total pressure, flow angle and total temperature distributions at the stage inlet we performed a numerical modeling of the combustor chamber of the investigated engine. The second part is a flow modeling in the turbine stage using flow parameters averaging on the stator-rotor interface (steady approach). Here we used sufficiently finer grid discretization to model all perforation holes on the stator vane and rotor blade, endwalls films in detail and to apply conjugate heat transfer approach for the rotor blade. Final results were obtained applying the results of steady and unsteady approaches. Experimental data of the investigated blade heat conditions are presented in the paper. These data were obtained during full size experimental testing the core of the engine and were collected using two different type of experimental equipment: thermocouples and thermo-crystals. The comparison of experimental data and final results meets the requirements of our investigation.

Collinear-Type Statically Balanced Compliant Micro Mechanism (SB-CMM): Experimental Comparison Between Pre-Curved and Straight Beams

2011 ◽  
Author(s):  
Nima Tolou ◽  
Pablo Estevez ◽  
Just L. Herder
Keyword(s):  
Experimental Data ◽  
Range Of Motion ◽  
Robust Design ◽  
Positive Constant ◽  
Experimental Comparison ◽  
Constant Force ◽  
Finite Range ◽  
Curved Beams ◽  
Actuation Force ◽  
Fabrication Errors

The feasibility of collinear-type statically balanced compliant micro mechanism (SB-CMM) with pre-curved beams has been studied experimentally and compares to those with initially straight beams. The collinear-type SB-CMM is a near zero stiffness micro mechanism with a near zero actuation force in a finite range of motion. However, from the experimental data, it was found that the collinear-type SB-CMM are sensitive to fabrication errors, as a results negative or positive constant force instead of zero actuation force maybe obtained. For the case of pre-curved beams, the curvature can be tuned for better zero stiffness behavior. Further improvements in the concept are considered towards a robust design and reliable prototypes, such as optimization and accurate dimensioning and fabrication.

High Accuracy Modeling Method for Photovoltaic Arrays

2012 ◽  
Vol 512-515 ◽  
pp. 238-241
Author(s):  
Soliman Mahmoud ◽  
Heba Mohamed
Keyword(s):  
Experimental Data ◽  
Nonlinear Equation ◽  
High Accuracy ◽  
Solar Array ◽  
Model Parameters ◽  
Main Theme ◽  
Mathematical Methods ◽  
Robust Algorithm ◽  
Photovoltaic Arrays ◽  
Pv Cell

This paper proposes high accuracy modeling approach for PV arrays. The I-V characteristic of PV cell is described by nonlinear equation that’s complicated to be solved by the ordinary mathematical methods. The main theme of this contribution is to use a robust algorithm to solve for all single diode model parameters. Validation of the model with experimental data of Solarex MSX60 solar array is provided.

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