scholarly journals Analytical Modeling of Particle Interference in Micro-abrasive Jets

2021 ◽  
Author(s):  
Tom Burzynski
Keyword(s):  
Computer Simulation ◽  
Analytical Modeling ◽  
Radial Symmetry ◽  
Experimental Techniques ◽  
Analytical Models ◽  
High Flux ◽  
Critical Flux ◽  
Particle Spacing ◽  
Nozzle Axis

Two existing analytical models of particle interference in non-divergent particle jets were modified to include radial symmetry of the particle jet across the nozzle axis, inter-particle spacing, and more complex rebound geometry. Two novel experimental techniques for obtaining the particle spatial and velocity distributions across a micro-abrasive jet were then devised and rigorously tested. One of the above mentioned analytical models was then chosen to be further modified to include the above-mentioned modifications along with the effect of a divergent jet, the ability to simulate high flux cases, and experimentally obtained particle spatial and velocity distributions. All of the models were tested at various jet conditions. The results of the models were quantitatively compared to a previously developed computer simulation and were found to qualitatively agree with previous experimental observations. The modified models allow the critical flux below which inter-particle interference is likely to occur to be determined.

scholarly journals Analytical Modeling of Particle Interference in Micro-abrasive Jets

2021 ◽  
Author(s):  
Tom Burzynski
Keyword(s):  
Computer Simulation ◽  
Analytical Modeling ◽  
Radial Symmetry ◽  
Experimental Techniques ◽  
Analytical Models ◽  
High Flux ◽  
Critical Flux ◽  
Particle Spacing ◽  
Nozzle Axis

Two existing analytical models of particle interference in non-divergent particle jets were modified to include radial symmetry of the particle jet across the nozzle axis, inter-particle spacing, and more complex rebound geometry. Two novel experimental techniques for obtaining the particle spatial and velocity distributions across a micro-abrasive jet were then devised and rigorously tested. One of the above mentioned analytical models was then chosen to be further modified to include the above-mentioned modifications along with the effect of a divergent jet, the ability to simulate high flux cases, and experimentally obtained particle spatial and velocity distributions. All of the models were tested at various jet conditions. The results of the models were quantitatively compared to a previously developed computer simulation and were found to qualitatively agree with previous experimental observations. The modified models allow the critical flux below which inter-particle interference is likely to occur to be determined.

Motorcycle Analytical Modeling Including Tire–Wheel Nonuniformities for Ride Comfort Analysis

2017 ◽  
Vol 45 (2) ◽  
pp. 101-120 ◽  
Author(s):  
Matheus de B. Vallim ◽  
José M. C. Dos Santos ◽  
Argemiro L. A. Costa
Keyword(s):  
Degrees Of Freedom ◽  
Analytical Modeling ◽  
Ride Comfort ◽  
Experimental Tests ◽  
Rotational Frequency ◽  
Analytical Models ◽  
Vertical Force ◽  
Lumped Mass ◽  
Multi Body ◽  
4 Degrees Of Freedom

ABSTRACT The transmission of vibrations in motorcycles and their perception by the passengers are fundamental in comfort analysis. Tire nonuniformities can generate self-excitations at the rotational frequency of the wheel and contribute to the ride vibration environment. In this work a multi-body motorcycle model is built to evaluate the ride comfort with respect to tire nonuniformities. The aim is to obtain a multi–degrees-of-freedom dynamic model that includes both the contributions of the motorcycle and tire–wheel assembly structures. This representation allows the tire nonuniformities to predict the vertical force variations on the motorcycle and can be used through a root mean square acceleration evaluation for ride comfort analysis. The motorcycle model proposed is a 10-degrees-of-freedom system, where each tire–wheel is a 4-degrees-of-freedom model. The tire–wheel assemblies include two types of nonuniformities: lumped mass imbalance and radial run-out. Simulations of analytical models are compared with experimental tests.

scholarly journals Validated Analytical Modeling of Diesel Engines Intake Manifold with a Flexible Crankshaft

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1287
Author(s):  
Salah A.M. Elmoselhy ◽  
Waleed F. Faris ◽  
Hesham A. Rakha
Keyword(s):  
Mass Flow Rate ◽  
Relative Error ◽  
Mass Flow ◽  
Flow Rate ◽  
Diesel Engines ◽  
Analytical Modeling ◽  
Vacuum Pressure ◽  
Analytical Models ◽  
Intake Manifold ◽  
Flow Losses

The flexibility of a crankshaft exhibits significant nonlinearities in the analysis of diesel engines performance, particularly at rotational speeds of around 2000 rpm. Given the explainable mathematical trends of the analytical model and the lack of available analytical modeling of the diesel engines intake manifold with a flexible crankshaft, the present study develops and validates such a model. In the present paper, the mass flow rate of air that goes from intake manifold into all the cylinders of the engine with a flexible crankshaft has been analytically modeled. The analytical models of the mass flow rate of air and gas speed dynamics have been validated using case studies and the ORNL and EPA Freeway standard drive cycles showing a relative error of 7.5% and 11%, respectively. Such values of relative error are on average less than those of widely recognized models in this field, such as the GT-Power and the CMEM, respectively. A simplified version for control applications of the developed models has been developed based on a sensitivity analysis. It has been found that the flexibility of a crankshaft decreases the mass flow rate of air that goes into cylinders, resulting in an unfavorable higher rate of exhaust emissions like CO. It has also been found that the pressure of the gas inside the cylinder during the intake stroke has four elements: a driving element (intake manifold pressure) and draining elements (vacuum pressure and flow losses and inertial effect of rotating mass). The element of the least effect amongst these four elements is the vacuum pressure that results from the piston's inertia and acceleration. The element of the largest effect is the pressure drop that takes place in the cylinder because of the air/gas flow losses. These developed models are explainable and widely valid so that they can help in better analyzing the performance of diesel engines.

Anisotropic Multishell Analytical Modeling of an Intervertebral Disk Subjected to Axial Compression

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Sébastien Demers ◽  
Sylvie Nadeau ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Analytical Modeling ◽  
Soft Tissues ◽  
Intervertebral Disk ◽  
Analytical Models ◽  
Alternative Methods ◽  
Anulus Fibrosus ◽  
Methodological Triangulation ◽  
Improve Model ◽  
Model Realism ◽  
Methods Analytical

Studies on intervertebral disk (IVD) response to various loads and postures are essential to understand disk's mechanical functions and to suggest preventive and corrective actions in the workplace. The experimental and finite-element (FE) approaches are well-suited for these studies, but validating their findings is difficult, partly due to the lack of alternative methods. Analytical modeling could allow methodological triangulation and help validation of FE models. This paper presents an analytical method based on thin-shell, beam-on-elastic-foundation and composite materials theories to evaluate the stresses in the anulus fibrosus (AF) of an axisymmetric disk composed of multiple thin lamellae. Large deformations of the soft tissues are accounted for using an iterative method and the anisotropic material properties are derived from a published biaxial experiment. The results are compared to those obtained by FE modeling. The results demonstrate the capability of the analytical model to evaluate the stresses at any location of the simplified AF. It also demonstrates that anisotropy reduces stresses in the lamellae. This novel model is a preliminary step in developing valuable analytical models of IVDs, and represents a distinctive groundwork that is able to sustain future refinements. This paper suggests important features that may be included to improve model realism.

scholarly journals COMPARATIVE ANALYSIS BETWEEN ANALYTICAL MODELS FOR CORE LOSS CALCULATION APPLIED TO INDUCTORS WITH PREMAGNETIZATION USING HIGH FLUX MATERIAL

2020 ◽  
Vol 25 (4) ◽  
pp. 1-8
Author(s):  
Pedro C. Bolsi ◽  
Edemar O. Prado ◽  
Hamiltom Confortin Sartori ◽  
José Renes Pinheiro
Keyword(s):  
Comparative Analysis ◽  
Core Loss ◽  
Analytical Models ◽  
High Flux ◽  
Loss Calculation

Quantitative Modeling of Stress and Coping

2018 ◽  
pp. 74-96
Author(s):  
Richard W. J. Neufeld ◽  
Bryan Grant
Keyword(s):  
Computer Simulation ◽  
Analytical Modeling ◽  
Stress And Coping ◽  
Quantitative Modeling ◽  
Formal Modeling ◽  
Connectionist Networks ◽  
Scientific Disciplines ◽  
Dynamical Nature ◽  
Empirical Tests ◽  
And Coping

Forms of modeling in the field are described in nontechnical terms. Included are analytical (mathematical), computational (computer simulation, mainly of connectionist networks), and statistical (generic, transcontent data theory, and methods) modeling. Distinctions among modeling forms are stipulated, and each is exposited through the method of illustration, with exemplary prototypes. Potential avenues of integration among complementing types of analytical modeling are identified. Emphasized throughout is the demonstrable need to invoke formal modeling to rigorously address the long-held dynamical nature of the topic domain. It is noted that analytical modeling can disclose otherwise intractable information, including that with implications for stress-related intervention; it can also prescribe its own empirical tests and measures, resembling theory-assessment technology found in longer established scientific disciplines.

A cost optimization study of flux and fouling rate for UF in the water industry

2008 ◽  
Vol 8 (1) ◽  
pp. 113-120 ◽  
Author(s):  
G. K. Pearce
Keyword(s):  
Membrane Fouling ◽  
Cost Optimization ◽  
Plant Size ◽  
Operating Pressure ◽  
High Flux ◽  
Chemical Cleaning ◽  
Critical Flux ◽  
Membrane Area ◽  
Optimization Study ◽  
The Relationship

Designing a commercial UF/MF system is an exercise in compromise. Selecting a high flux reduces capex by minimizing the membrane area required, but increases operating costs due to the increased chemical cleaning frequency, higher waste disposal volumes, and higher operating pressure. Most commercial systems are designed to run at fluxes significantly above the critical flux, so a degree of fouling and a reliance on chemical cleaning is inherent to the design. This paper examines the relationship between flux and membrane fouling rate through a review of experimental field data. The analysis shows that fouling rate increases exponentially with flux, with a function dependent upon the characteristics of the feed. The paper then presents the results of a cost optimization study in which Total Water Cost (TWC) is evaluated as a function of feed source and plant size for different CIP cleaning frequencies. The minimum TWC occurs in all cases for CIP frequencies of between 1/week and 1/month. Smaller plants with low fouling feeds have an optimum near 1 CIP/week using a relatively high flux design. In contrast, feeds with higher fouling propensity, and medium or large plant sizes have a TWC optimum close to 1 CIP/month, and should use a lower design flux. It is suggested that the flux corresponding to the TWC optimum should be designated the sustainable flux.

scholarly journals Визуализация динамических вихревых структур в магнитных пленках с одноосной анизотропией (микромагнитное моделирование)

2018 ◽  
Vol 60 (2) ◽  
pp. 294
Author(s):  
В.В. Зверев ◽  
И.М. Изможеров ◽  
Б.Н. Филиппов
Keyword(s):  
Computer Simulation ◽  
Domain Boundary ◽  
Vortex Structures ◽  
Analytical Models ◽  
Dynamic Processes ◽  
Topological Properties ◽  
Soft Magnetic ◽  
Magnetization Dynamics ◽  
Planar Anisotropy ◽  
Moving Domain

AbstractThree-dimensional computer simulation of dynamic processes in a moving domain boundary separating domains in a soft magnetic uniaxial film with planar anisotropy is performed by numerical solution of Landau-Lifshitz-Gilbert equations. The developed visualization methods are used to establish the connection between the motion of surface vortices and antivortices, singular (Bloch) points, and core lines of intrafilm vortex structures. A relation between the character of magnetization dynamics and the film thickness is found. The analytical models of spatial vortex structures for imitation of topological properties of the structures observed in micromagnetic simulation are constructed.

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