Analytical Modeling of Wax Plug Transportation during Pipeline Pigging Using a Foam Pig

2021 ◽  
pp. 1-14
Author(s):  
Xuedong Gao ◽  
Qiyu Huang ◽  
Xun Zhang ◽  
Yu Zhang
Keyword(s):  
Analytical Model ◽  
Analytical Modeling ◽  
Functional Relationship ◽  
Viscoelastic Behavior ◽  
Linear Increase ◽  
Formation Condition ◽  
Breaking Force ◽  
Time Effects ◽  
Spring Element ◽  
Viscous Component

Summary In our previous article (Gao et al. 2020), a mathematical model including elastic and yield components but not viscous component was developed to predict the wax plug transportation force. In this work, an analytical model was developed to calculate the wax plug transportation force, and the viscous component was introduced into the analytical model to capture some of the time effects. In this analytical model, the viscoelastic behavior of the wax deposit was characterized by a three-parameter model, formulated by adding an additional spring element to the Kelvin-Voight model. The Laplace transformation was used to solve the model. According to the calculated results of the analytical model, the transportation force of the wax plug was observed to slightly increase with time and then tended to level off. To obtain a parameter in the model and verify the model, the pigging experiments were conducted using foam pigs. During the pigging process of the foam pig, the wax plug transportation force in a five-phase wax removal profile was determined by taking the steady wax breaking force from the resistive force of the wax layer. Moreover, the linear increase of the wax plug transportation force per unit contact area with the shear strength of the wax layer was found, as described by the functional relationship in the analytical model. The interfacial lubrication coefficient calculated from the experimental data based on the analytical model is between the coefficient for diesel-prepared deposits and coefficient for oil-A-prepared deposits. Experimental verification results show that the average relative error of the model is 12.47%. Field implication was proposed to illustrate the application of the model and the formation condition of the wax blockage.

scholarly journals Cheating at Craps

2021 ◽  
Vol 48 (4) ◽  
pp. 53-61
Author(s):  
Andrea Marin ◽  
Carey Williamson
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Modeling And Simulation ◽  
Analytical Model ◽  
Quantitative Evaluation ◽  
Mathematical Analysis ◽  
Simulation Modeling ◽  
Analytical Modeling ◽  
The World ◽  
Simulation Results

Craps is a simple dice game that is popular in casinos around the world. While the rules for Craps, and its mathematical analysis, are reasonably straightforward, this paper instead focuses on the best ways to cheat at Craps, by using loaded (biased) dice. We use both analytical modeling and simulation modeling to study this intriguing dice game. Our modeling results show that biasing a die away from the value 1 or towards the value 5 lead to the best (and least detectable) cheating strategies, and that modest bias on two loaded dice can increase the winning probability above 50%. Our Monte Carlo simulation results provide validation for our analytical model, and also facilitate the quantitative evaluation of other scenarios, such as heterogeneous or correlated dice.

Stochastic Characterization of Epoxies to Predict Performance Uncertainty of Photonic Packages

2004 ◽  
Author(s):  
S. Radhakrishnan ◽  
G. Subbarayan ◽  
L. Nguyen ◽  
W. Mazotti
Keyword(s):  
Analytical Model ◽  
Stochastic Analysis ◽  
Coupling Efficiency ◽  
Viscoelastic Behavior ◽  
Material Behavior ◽  
Considerable Uncertainty ◽  
Stochastic Characterization ◽  
Degree Of Confidence ◽  
Extensive Experimental Data

There is considerable uncertainty in the prediction of performance of a system mainly due to idealizations in geometry, material behavior, and loading history. Uncertainties in geometry can be predicted and controlled using tighter tolerances. However, the models currently used to describe material behavior are mostly deterministic. To predict the coupling efficiency of a photonic system to greater degree of confidence, stochastic analysis procedures are necessary. As part of this analysis, the behavior of materials must be stochastically characterized. In this paper, we present extensive experimental data on thermally and UV-cured epoxies typically used in photonic packages to enable stochastic analysis. The test data includes the viscoelastic behavior. We present analytical model to obtain the variation in the displacement of the epoxies resulting from its stochastic viscoelastic behavior. We utilize the analytical model to predict the uncertainty in the coupling efficiency of a generic photonic package.

scholarly journals Analytical modeling of reservoir effect on electromigration in Cu interconnects

2007 ◽  
Vol 22 (1) ◽  
pp. 152-156 ◽  
Author(s):  
Zhenghao Gan ◽  
A.M. Gusak ◽  
W. Shao ◽  
Zhong Chen ◽  
S.G. Mhaisalkar ◽  
...  
Keyword(s):  
Analytical Model ◽  
Analytical Modeling ◽  
Interface Energy ◽  
Design Guidelines ◽  
Void Size ◽  
Electrical Field ◽  
Electrical Field Gradient ◽  
Damascene Interconnects ◽  
Extension Length ◽  
Electron Wind

Electromigration (EM) in Cu dual-damascene interconnects with extensions (also described as overhangs or reservoirs) ranging from 0 to 120 nm in the upper metal (M2) was investigated by an analytical model considering the work of electron wind and surface/interface energy. It was found that there exists a critical extension length beyond which increasing extension lengths ceases to prolong electromigration lifetimes. The critical extension length is a function of void size and electrical field gradient. The analytical model agrees very well with existing experimental results. Some design guidelines for electromigration-resistant circuits could be generated by the model.

scholarly journals Calculation of airgap function and inductance using analytical modeling of rotor magnetic characteristics of an IPM motor under loaded condition

2021 ◽  
Author(s):  
BINITA NANDA ◽  
Praveen Kumar
Keyword(s):  
Optimal Design ◽  
Energy Conversion ◽  
Analytical Model ◽  
Motor Performance ◽  
Analytical Modeling ◽  
Design Parameters ◽  
Magnetic Characteristics ◽  
Design Phase ◽  
Initial Design ◽  
The Relationship

<div>This paper proposes an analytical model to calculate the airgap function and inductance, which can be used to get an optimal design during the initial design phase. It investigates the relationship between the design parameters of the rotor and the motor performance.</div><div><br></div><div>This paper is under review in IEEE Transactions on Energy Conversion.<br></div>

scholarly journals The Analytical Comparative Analysis of Electromagnetic Characteristics of Four Typical Radial Flux Permanent Magnet Eddy Current Couplers

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8407
Author(s):  
Yibo Li ◽  
Jiacai Huang ◽  
Fangzheng Gao ◽  
Zhiying Zhu ◽  
Yufei Han ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
Analytical Model ◽  
Eddy Current ◽  
Analytical Modeling ◽  
Magnetic Circuit ◽  
Radial Flux ◽  
Higher Power ◽  
Interior Permanent Magnet ◽  
Fea Simulation ◽  
Electromagnetic Characteristics

The analytical model of a permanent magnet eddy current coupler (PMECC) is mainly used for evaluation of its characteristics and the initial optimization of design. Based on the equivalent magnetic circuit method, this paper carries out analytical modeling for four typical PMECCs composed of surface-mounted and interior permanent magnet, slotted and non-slotted conductor rotors, which provides a theoretical basis for the subsequent research in this paper. The basic electromagnetic characteristics of the PMECCs are investigated by the established analytical model. Simultaneously, the analytical results about permeance, flux density, torque and power are verified by FEA simulation. The analysis results show that the slotted CR will obtain a much higher power density, and the iron loss mainly exists in the CRs. In addition, the analytical and FEA results agree well, which proves the reliability of the proposed, nearly unified analytical model.

scholarly journals Modeling, Investigation, and Mitigation of AC Losses in IPM Machines with Hairpin Windings for EV Applications

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 8034
Author(s):  
Mingyu Choi ◽  
Gilsu Choi
Keyword(s):  
Finite Element ◽  
Analytical Model ◽  
Parametric Study ◽  
Analytical Modeling ◽  
Design Parameters ◽  
Ac Losses ◽  
Comprehensive Investigation ◽  
Interior Permanent Magnet ◽  
Phase Arrangement ◽  
Significant Attention

Interior permanent magnet (IPM) machines with hairpin windings have attracted significant attention in EV applications owing to their low DC resistance and excellent thermal capabilities. In this paper, we present a comprehensive investigation of AC winding losses in IPM machines for traction applications, including analytical modeling, the influence of design parameters, and finite element (FE) verification. The proposed analytical model can predict the trends in AC winding losses for any number of bar conductors and slot/pole combinations. The results of the parametric study, obtained via the analytical model, are presented to examine the effects of key design parameters, such as conductor width and height, phase arrangement, and slot-per-pole-per-phase (SPP). To incorporate more practical issues into the analysis of IPM machines with hairpin windings, extensive FE simulations were conducted. The results indicated that the AC winding losses decrease with an increasing number of conductor layers and phases inside the slot.

scholarly journals Analytical modeling of mine water rebound: Three case studies in closed hard-coal mines in Germany

2021 ◽  
Vol 15 (3) ◽  
pp. 22-30
Author(s):  
Dmytro Rudakov ◽  
Sebastian Westermann
Keyword(s):  
Hydraulic Conductivity ◽  
Analytical Model ◽  
Water Flow ◽  
Mine Water ◽  
Input Data ◽  
Analytical Modeling ◽  
Coal Mines ◽  
Hard Coal ◽  
Preliminary Evaluation ◽  
Working Volume

Purpose.In this paper we present and validate an analytical model of water inflow and rising level in a flooded mine and examine the model robustness and sensitivity to variations of input data considering the examples of three closed hard-coal mines in Germany. Methods. We used the analytical solution to a boundary value problem of radial ground water flow to the shaft, treated as a big well, and water balance relations for the series of successive stationary positions of a depression cone to simulate a mine water rebound in the mine taking into account vertical distribution of hydraulic conductivity, residual volume of underground workings, and natural pores. Findings. The modeling demonstrated very good agreement with the measured data for all the studied mines. The maximum relative deviation for the mine water level during the measurement period did not exceed 2.1%; the deviation for the inflow rate to a mine before its flooding did not exceed 0.8%. Sensitivity analysis revealed the higher significance of the residual working volume and hydraulic conductivity for mine water rebound in the case of thick overburden and the growing significance of the infiltration rate and the flooded area size in the case of lower overburden thickness. Originality.The developed analytical model allows realistic prediction of transient mine water rebound and inflow into a mine with layered heterogeneity of rocks, irregular form of the drained area, and with the inflow/outflow to a neighboring mine and the volume of voids as a distributed parameter without gridding the flow domain performed in numerical models. Practical implications.The study demonstrated the advantages of analytical modeling as a tool for preliminary evaluation and prediction of flooding indicators and parameters of mined out disturbed rocks. In case of uncertain input data, modeling can be considered as an attractive alternative to usually applied numerical methods of modeling ground and mine water flow.

MAGNETOELASTIC ELECTROMAGNETIC ACOUSTIC TRANSFORMATION. Part 5

2019 ◽  
pp. 14-22
Author(s):  
V. A. Komarov
Keyword(s):  
Analytical Model ◽  
Functional Relationship ◽  
Spontaneous Magnetization ◽  
Internal Stresses ◽  
Magnetization Process ◽  
Saturation Magnetostriction ◽  
Tensile Stresses ◽  
Compressive Stresses

The analytical model of the applied and internal stresses influence on the efficiency of EMAT in the region of spontaneous magnetization vectors rotation processes (a saturation magnetostriction ls < 0) in the case of strong polarizing field is considered.It has been shown analytically and confirmed experimentally that in the presence of applied s0 or internal si stresses the region of maximum EMAT efficiency in the polarizing field changes. If the product lss0 or lssi is greater than zero then this region shifts to the weaker fields. If the product lss0 or lssi is less than zero then the maximum of EMAT efficiency shifts to the stronger fields region (magnetization process is difficult) compared to the stresses absence in the sample. The EMAT efficiency for materials with ls < 0 increases with the tensile stresses increasing and decreas with the compressive stresses increasing. It has been shown analytically and confirmed experimentally that the presence of internal stresses in the material changes the efficiency of EMAT inversely related to the magnitude of these stresses. The functional relationship between EMAT efficiency and internal stresses is demonstrated.

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