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.

Deregulation of p53-dependent microRNAs: the results of mathematical modeling

2017 ◽  
Vol 12 (1) ◽  
pp. 151-175 ◽  
Author(s):  
О.Ф. Воропаева ◽  
O.F. Voropaeva
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Numerical Analysis ◽  
Neurodegenerative Disease ◽  
Numerical Investigation ◽  
Tumor Markers ◽  
Critical Properties ◽  
Laboratory Studies ◽  
The Mathematical Model ◽  
Good Agreement

The mathematical model of the dynamics of the tumor markers network p53–Mdm2–microRNA for microRNA class with a direct positive connection with p53 was formulated. Numerical investigation of the microRNA functioning in conditions of the deregulation of p53 and p53–Mdm2-network was carried out. The deregulation of microRNA in detail was studied. The situations in which p53, its inhibitor Mdm2 and microRNAs exhibit critical properties for the patient's status and can be identified as diagnostic markers of cancer and neurodegenerative disease were studied. The results of numerical analysis are in good agreement with the data of clinical and laboratory studies of known microRNAs.

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.

Numerical analysis of temperature field in a thawing embankment in permafrost

1988 ◽  
Vol 25 (1) ◽  
pp. 163-166 ◽  
Author(s):  
Mu Shen
Keyword(s):  
Mathematical Model ◽  
Temperature Field ◽  
Heat Conduction ◽  
Numerical Analysis ◽  
Finite Elements ◽  
Measured Data ◽  
Two Dimensional ◽  
Nonlinear Mathematical Model ◽  
Permafrost Thawing ◽  
Good Agreement

The objective of this paper is to present a numerical analysis by finite elements of a two-dimensional nonlinear mathematical model for heat conduction with phase change in a thawing embankment in permafrost. The calculated results are compared with actual measured data, and good agreement is obtained. All calculations were carried out on a personal computer. Key words: permafrost, thawing, embankment, temperature field, numerical analysis.

Inducing Frictional Force to Enhance the Transient Response in Beams

2019 ◽  
Vol 22 (2) ◽  
pp. 88-93
Author(s):  
Hamed Khanger Mina ◽  
Waleed K. Al-Ashtrai
Keyword(s):  
Numerical Analysis ◽  
Transient Response ◽  
Frictional Force ◽  
Damping Ratio ◽  
Experimental Results ◽  
Damping Capacity ◽  
Tightening Force ◽  
Contact Areas ◽  
Good Agreement ◽  
Ansys Workbench

This paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results showed that the two beams vibrate independently when the bolts were loosed and the structure stiffness is about 20 N/m and the damping ratio is about 0.008. With increasing the bolts tightening, the stiffness and the damping ratio of the structure were also increased till they reach their maximum values when the tightening force equals to 8330 N, where the structure now has stiffness equals to 88 N/m and the damping ratio is about 0.062. Beyond this force value, increasing the bolts tightening has no effect on stiffness of the structure while the damping ratio is decreased until it returned to 0.008 when the bolts tightening becomes immense and the beams behave as one beam of double thickness.

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.

Dose-window dependence on Si crystal orientation in separation by implanted oxygen substrate formation

2004 ◽  
Vol 19 (12) ◽  
pp. 3607-3613 ◽  
Author(s):  
H. Iikawa ◽  
M. Nakao ◽  
K. Izumi
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Crystal Orientation ◽  
Oxygen Ion ◽  
The Difference ◽  
First Time ◽  
Good Agreement

Separation by implemented oxygen (SIMOX)(111) substrates have been formed by oxygen-ion (16O+) implantation into Si(111), showing that a so-called “dose-window” at 16O+-implantation into Si differs from Si(100) to Si(111). In SIMOX(100), an oxygen dose of 4 × 1017/cm2 into Si(100) is widely recognized as the dose-window when the acceleration energy is 180 keV. For the first time, our work shows that an oxygen dose of 5 × 1017/cm2 into Si(111) is the dose-window for the formation of SIMOX(111) substrates when the acceleration energy is 180 keV. The difference between dose-windows is caused by anisotropy of the crystal orientation during growth of the faceted buried SiO2. We also numerically analyzed the data at different oxidation velocities for each facet of the polyhedral SiO2 islands. Numerical analysis results show good agreement with the experimental data.

Evaluation of Motorized Rotating Pancake Coil Probe Signals Simulated by Numerical Analysis in Steam Generator Tubes

2006 ◽  
Vol 321-323 ◽  
pp. 451-454
Author(s):  
Joo Young Yoo ◽  
Sung Jin Song ◽  
Chang Hwan Kim ◽  
Hee Jun Jung ◽  
Young Hwan Choi ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Analysis ◽  
Steam Generator ◽  
Integral Method ◽  
Volume Integral ◽  
Analysis Software ◽  
Steam Generator Tubes ◽  
Calibration Tool ◽  
High Possibility ◽  
Good Agreement

In the present study, the synthetic signals from the combo tube are simulated by using commercial electromagnetic numerical analysis software which has been developed based on a volume integral method. A comparison of the simulated signals to the experiments is made for the verification of accuracy, and then evaluation of five deliberated single circumferential indication signals is performed to explore a possibility of using a numerical simulation as a practical calibration tool. The good agreement between the evaluation results for two cases (calibration done by experiments and calibration made by simulation) demonstrates such a high possibility.

Investigation of Circular and Shaped Effusion Cooling Arrays for Combustor Liner Application—Part 2: Numerical Analysis

2009 ◽  
Author(s):  
A. Andreini ◽  
C. Bianchini ◽  
A. Ceccherini ◽  
B. Facchini ◽  
L. Mangani ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Cross Flow ◽  
Lateral Spreading ◽  
Elliptical Cross ◽  
Injection Angle ◽  
Blowing Ratio ◽  
Combustor Liner ◽  
Effectiveness Data ◽  
Overall Effectiveness ◽  
Good Agreement

A numerical analysis of two different effusion cooled plates, with a feasible arrangement for combustor liner application, is presented in this paper. Though having the same porosity and very shallow injection angle (17°), the first configuration presents a “conventional” circular drilling, while the other has “shaped” holes with such an elliptical cross-section that leads to a circular imprint on the cooled surface. Either geometries were the object of an experimental survey in which both adiabatic and overall effectiveness were measured. In order to compensate for the lack of detailed aerodynamic measurements, 3D CFD computations were performed for the two geometries. Steady state RANS calculations were carried out using a k–ε Two Layer turbulence model, both in the standard isotropic and in an algebraically corrected non isotropic version specifically tuned to better predict the lateral spreading of jets in a cross flow. Flow characteristic reproduce typical effusion cooled combustor liner conditions with blowing ratio of 5 and coolant jet Reynolds number of 12500. Even though good agreement could not be obtained comparing thermal adiabatic effectiveness with experiments, the findings of the experiments regarding the rating of the cooling efficiency of the two configurations were confirmed. Additionally, conjugate simulations were performed for the circular hole geometry in order to quantify heat transfer effects and to directly compare them with raw experimental overall effectiveness data.

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