scholarly journals Investigation of dynamics and power needs for container unloading from ship process

2021 ◽  
Vol 24 (1) ◽  
pp. 89-99
Author(s):  
Jolanta Janutėnienė ◽  
Marijonas Bogdevičius ◽  
Valdas Jankūnas ◽  
Jūratė Janutėnaitė-Bogdanienė ◽  
Arūnas Andziulis ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Contact Forces ◽  
Experimental Measurements ◽  
Operational Problem ◽  
Frictional Forces ◽  
Power Needs

The operational problem of container unloading from the ship is analyzed in this paper. Dynamic “crane-cargo-ship” system was investigated, and a mathematical model was created. In the model, the gap between the container and the ship’s cargo hold, the mass of the cargo, the container’s center of the mass, and the frictional forces that may occur during lifting from the cargo hold were estimated. Numerical analysis of the system was performed. Results of numerical analysis were compared with experimental measurements of containers unloading process in port. Requirement of lifting power was modelled depending on mass of cargo. Additional power needs in case of contact forces between container and wall of the ship’s cargo hold were calculated. Rational lifting conditions could be deduced using a created mathematical model and the reliability of the container and cargo during lifting could be deduced.

scholarly journals Experimental, analytical and numerical analysis of voltage distribution along the cap-and-pin insulators

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Mladen Banjanin
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Electrostatic Field ◽  
Field Model ◽  
Experimental Measurements ◽  
Voltage Distribution ◽  
Specialized Software ◽  
The Earth ◽  
Good Agreement ◽  
Linear Voltage

This paper deals with the experimental, analytical and numerical analysis of voltage distribution along the cap-and-pin insulators. Five different insulators strings are analyzed, consisting of two, three, four, five and six cap-and-pin U40BL glass disc insulators. Experimental measurements are performed in the high voltage laboratory at the Faculty of Electrical Engineering East Sarajevo. Measurement of the voltage distribution along the disc insulators is performed by using measuring sphere gap. Analytical calculations are performed by using mathematical model which considers parasite self-capacitances of disc insulators, as well as their parasite capacitances to the earth and to the phase conductor. Calculations of the parasite capacitances values are performed and optimum values which lead to the minimum difference between measured and calculated results are suggested. Numerical analyses of the non-linear voltage distribution are performed by using electrostatic field model in software Comsol Multyphisics. 2D axisymmetric models of the cap-and-pin insulators are developed. Despite the measuring configuration is not suitable for numerical analysis, relatively good agreement between the measured results and results calculated by using specialized software are achieved.

scholarly journals Novel hot air engine and its mathematical model – experimental measurements and numerical analysis

2019 ◽  
Vol 14 (1) ◽  
pp. 47-58
Author(s):  
Gyula Kramer ◽  
Gabor Szepesi ◽  
Zoltán Siménfalvi
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Experimental Measurements ◽  
Hot Air

scholarly journals Theoretical and numerical analysis of novel COVID-19 via fractional order mathematical model

2021 ◽  
Vol 20 ◽  
pp. 103676
Author(s):  
Amjad Ali ◽  
Muhammad Yasin Khan ◽  
Muhammad Sinan ◽  
F.M. Allehiany ◽  
Emad E. Mahmoud ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Fractional Order ◽  
Theoretical And Numerical Analysis

The Numerical Analysis of the Velocity and Pressure Distribution of the Oil Film in Heavy Hydrostatic Thrust Bearing

2014 ◽  
Vol 541-542 ◽  
pp. 658-662
Author(s):  
Jian Li ◽  
Yuan Chen ◽  
Yang Chun Yu ◽  
Zhu Xin Tian ◽  
Yu Huang
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Pressure Distribution ◽  
Working Conditions ◽  
Thrust Bearing ◽  
Rotation Speed ◽  
The Other ◽  
Surface Load ◽  
Oil Film ◽  
Volume Method

To study the velocity and pressure distribution of the oil film in a heavy hydrostatic thrust bearing, a mathematical model of the velocity is proposed and the finite volume method (FVM) has been used to simulate the flow field under different working conditions. Some pressure experiments were carried out and the results verified the correctness of the simulation. It is concluded that the pressure distribution varies small under different rotation speed when the surface load on the workbench is constant. But the velocity of the oil film is influenced greatly by the rotation speed. When the rotation speed of the workbench is as quick as enough, the velocity of the oil film on one radial side of the pad will be zero, that is to say the lubrication oil will be drained from the other three sides of the recess.

Thickness Deformation of Constrained Layer Damping: An Experimental and Theoretical Evaluation

2000 ◽  
Vol 123 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Peter Y. H. Huang ◽  
Per G. Reinhall ◽  
I. Y. Shen ◽  
Jessica M. Yellin
Keyword(s):  
Mathematical Model ◽  
Transfer Functions ◽  
Viscoelastic Layer ◽  
Experimental Setup ◽  
Experimental Measurements ◽  
Constrained Layer Damping ◽  
Response Functions ◽  
Theoretical Evaluation ◽  
Calculated Frequency ◽  
Direct Measurements

This paper presents a study of thickness deformation of the viscoelastic material in constrained layer damping (CLD) treatments. The first goal of the study is to demonstrate the feasibility of using direct measurement to investigate thickness deformation in CLD treatments. The experimental setup consisted of a constrained layer beam cantilevered to a shaker, an accelerometer mounted at the cantilevered end, and two laser vibrometers that simultaneously measured the responses of the base beam and the constraining layer, respectively, at the free end. A spectrum analyzer calculated frequency response functions (FRFs) between the accelerometer inputs and the vibrometer outputs. Measured FRFs of the base beam and the constraining layer were compared to detect thickness deformation. Experimental results showed that direct measurements can detect thickness deformation as low as 0.5 percent. The second goal is to evaluate the accuracy of a mathematical model developed by Miles and Reinhall [7] that accounts for thickness deformation. FRFs were calculated by using the method of distributed transfer functions by Yang and Tan [13]. Comparison of the numerical results with the experimental measurements indicated that consideration of thickness deformation can improve the accuracy of existing constrained layer damping models when the viscoelastic layer is thick.

Modeling of a Finger-Follower Cam System With Verification in Contact Forces

1993 ◽  
Author(s):  
Wensyang Hsu ◽  
Albert P. Pisano
Keyword(s):  
Constraint Equation ◽  
Contact Forces ◽  
Valve Train ◽  
Dynamic Responses ◽  
Valve Lift ◽  
Distributed Parameter ◽  
Contact Points ◽  
Frictional Forces ◽  
Contact Position ◽  
Force Data

Abstract A lumped/distributed-parameter, dynamic model is developed to investigate the dynamic responses of a finger-follower valve train with the effects of an oscillating pivot, frictional forces between sliding surfaces, and a hydraulic lash adjuster. Based on the measured force data at low speed, an algorithm is derived to determine the dynamic Coulomb friction coefficients around maximum valve lift simultaneously at three contact points. A constraint equation is formulated to find the contact position between the cam and the follower kinematically. This makes it possible for the model to simulate the dynamic response of the cam system when the pivot is moving. A hydraulic lash adjuster acting as the pivot of the follower is also modeled with the effects of oil compressibility and oil refill mechanism. The model is numerically integrated and shown to have good agreement between simulation results and experimental data of contact forces at three different speeds. The maximum operating speed is limited by valve toss, loss contact between components. The model predicts toss between the hydraulic lash adjuster and the follower at 2535 rpm, and experiment indicates toss starting at 2520 rpm of camshaft speed.

scholarly journals Frequency multiplexed coherent φ-OTDR

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hannah M. Ogden ◽  
Matthew J. Murray ◽  
Joseph B. Murray ◽  
Clay Kirkendall ◽  
Brandon Redding
Keyword(s):  
Numerical Analysis ◽  
Pulse Train ◽  
State Of The Art ◽  
Average Power ◽  
Comprehensive Analysis ◽  
Experimental Measurements ◽  
Rayleigh Backscattering ◽  
Sensor Performance ◽  
Sensor Platform ◽  
Lower Noise

AbstractWe present a comprehensive analysis of a frequency multiplexed phase-measuring φ-OTDR sensor platform. The system uses a train of frequency-shifted pulses to increase the average power injected into the fiber and provide a diversity of uncorrelated Rayleigh backscattering measurements. Through a combination of simulations, numerical analysis, and experimental measurements, we show that this approach not only enables lower noise and mitigates interference fading, but also improves the sensor linearity. We investigate the sensor dependence on the length of the pulse train and characterize the sensor performance as a function of range, demonstrating operation from 1 to 50 km. Despite its relative simplicity, this platform enables state-of-the-art performance, including low crosstalk, high linearity, and a minimum detectable strain of only 0.6 p$$\varepsilon /\sqrt{\text{Hz}}$$ ε / Hz in a 10 km fiber with 10 m spatial resolution and a bandwidth of 5 kHz.

Design of a New Multi-Channel High-Low Pressure Micro-Ejection System

2011 ◽  
Vol 189-193 ◽  
pp. 4313-4317
Author(s):  
Wei Yang ◽  
Qiang Yin ◽  
Kun Wang Niu ◽  
Jiao Zhang ◽  
Wen Dong Zhang
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Structural Design ◽  
Structural Characteristics ◽  
Low Pressure ◽  
Classical Trajectory ◽  
Design Methods ◽  
Analysis And Design ◽  
Bullet Velocity

According to the structural characteristics of the multi-channel high-low pressure micro-ejection system,this paper sets up mathematical model of the trajectory based on the classical trajectory theory,makes numerical analysis to prove the rationality of the structural design,tests the pressure and bullet velocity of the launching system.The results show that the analysis and design methods of the multi-channel high-low pressure micro-ejection system are reasonable and reliable.

scholarly journals The Theory and Demonstration of the Solid-Fluid Transformation of Ice Water

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yong-Yan Wang ◽  
Xi-Yan Fan ◽  
Nan Qin ◽  
Jian-Guang Li ◽  
Chuan-Qi Su
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Special Geometry ◽  
Ice Water ◽  
Good Agreement

In this paper, a mathematical model for describing the solid-fluid transformation of ice water is put forward based on the special geometry cases. The correctness of the obtained model is verified through comparison with numerical analysis and experiments. The good agreement indicates that the obtained model is available for the study of the solid-fluid transformation of ice water. The theory derived in this paper lays a foundation for the research of solid-fluid transformation phenomena of other materials and may have important applications in engineering areas such as rheology, creep, and instability of materials.

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