scholarly journals Method for Calculating the Injection Effect to Create Air Circulation Inside Containers

2019 ◽  
Vol 9 (1) ◽  
pp. 3222-3224
Keyword(s):  
Mathematical Model ◽  
Structural Change ◽  
Turbulent Flow ◽  
Numerical Results ◽  
Hydrodynamic Equations ◽  
Injection Effect ◽  
Air Circulation ◽  
External Stream

The paper investigates the process of air circulation inside the container due to the effect of injection by an external stream. It is shown in the paper that injection can be created using the open hatch of the container, which is fixed at a certain angle. To calculate the emerging turbulent flow, a new effective mathematical model is used. The obtained numerical results of the hydrodynamic equations show that by a simple structural change in a simple container, air circulation inside the container can be significantly improved. This phenomenon gives a good perspective for the use of containers in the transportation of food.

scholarly journals Assessment of Steady and Unsteady Friction Models in the Draining Processes of Hydraulic Installations

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1888
Author(s):  
Óscar E. Coronado-Hernández ◽  
Ivan Derpich ◽  
Vicente S. Fuertes-Miquel ◽  
Jairo R. Coronado-Hernández ◽  
Gustavo Gatica
Keyword(s):  
Mathematical Model ◽  
Turbulent Flow ◽  
Water Velocity ◽  
Experimental Facility ◽  
Governing Equations ◽  
Pressure Oscillations ◽  
Air Pocket ◽  
Friction Models ◽  
The Mathematical Model

The study of draining processes without admitting air has been conducted using only steady friction formulations in the implementation of governing equations. However, this hydraulic event involves transitions from laminar to turbulent flow, and vice versa, because of the changes in water velocity. In this sense, this research improves the current mathematical model considering unsteady friction models. An experimental facility composed by a 4.36 m long methacrylate pipe was configured, and measurements of air pocket pressure oscillations were recorded. The mathematical model was performed using steady and unsteady friction models. Comparisons between measured and computed air pocket pressure patterns indicated that unsteady friction models slightly improve the results compared to steady friction models.

scholarly journals Analysis of a Mathematical Model for Drilling System With Reverse Air Circulation by Using the ANN-BHCS Technique

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 119188-119218
Author(s):  
Ashfaq Ahmad ◽  
Muhammad Sulaiman ◽  
Poom Kumam ◽  
Maharani Abu Bakar ◽  
Miftahuddin
Keyword(s):  
Mathematical Model ◽  
Drilling System ◽  
Air Circulation

scholarly journals Modelling Macrophage Infiltration into Avascular Tumours

2002 ◽  
Vol 4 (1) ◽  
pp. 21-38 ◽  
Author(s):  
C. E. Kelly ◽  
R. D. Leek ◽  
H. M. Byrne ◽  
S. M. Cox ◽  
A. L. Harris ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Spatial Structure ◽  
Random Motion ◽  
Numerical Results ◽  
Macrophage Infiltration ◽  
Numerical Techniques ◽  
Model Predictions ◽  
Independent Experimental Data

In this paper a mathematical model that describes macrophage infiltration into avascular tumours is presented. The qualitative accuracy of the model is assessed by comparing numerical results with independent experimental data that describe the infiltration of macrophages into two types of spheroids: chemoattractant-producing (hepa-1) and chemoattractant-deficient (or C4) spheroids. A combination of analytical and numerical techniques are used to show how the infiltration pattern depends on the motility mechanisms involved (i.e. random motion and chemotaxis) and to explain the observed differences in macrophage infiltration into the hepa-1 and C4 spheroids. Model predictions are generated to show how the spheroid's size and spatial structure and the ability of its constituent cells influence macrophage infiltration. For example, chemoattractant-producing spheroids are shown to recruit larger numbers of macrophages than chemoattractant-deficient spheroids of the same size and spatial structure. The biological implications of these results are also discussed briefly.

scholarly journals Free Interfaces at the Tips of the Cilia in the One-Dimensional Periciliary Layer

Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1961
Author(s):  
Kanognudge Wuttanachamsri
Keyword(s):  
Mathematical Model ◽  
Exact Solution ◽  
Free Boundary ◽  
Horizontal Plane ◽  
Numerical Solutions ◽  
Numerical Results ◽  
Brinkman Equation ◽  
Average Height ◽  
Free Interface ◽  
The Mathematical Model

Cilia on the surface of ciliated cells in the respiratory system are organelles that beat forward and backward to generate metachronal waves to propel mucus out of lungs. The layer that contains the cilia, coating the interior epithelial surface of the bronchi and bronchiolesis, is called the periciliary layer (PCL). With fluid nourishment, cilia can move efficiently. The fluid in this region is named the PCL fluid and is considered to be an incompressible, viscous, Newtonian fluid. We propose there to be a free boundary at the tips of cilia underlining a gas phase while the cilia are moving forward. The Brinkman equation on a macroscopic scale, in which bundles of cilia are considered rather than individuals, with the Stefan condition was used in the PCL to determine the velocity of the PCL fluid and the height/shape of the free boundary. Regarding the numerical methods, the boundary immobilization technique was applied to immobilize the moving boundaries using coordinate transformation (working with a fixed domain). A finite element method was employed to discretize the mathematical model and a finite difference approach was applied to the Stefan problem to determine the free interface. In this study, an effective stroke is assumed to start when the cilia make a 140∘ angle to the horizontal plane and the velocitiesof cilia increase until the cilia are perpendicular to the horizontal plane. Then, the velocities of the cilia decrease until the cilia make a 40∘ angle with the horizontal plane. From the numerical results, we can see that although the velocities of the cilia increase and then decrease, the free interface at the tips of the cilia continues increasing for the full forward phase. The numerical results are verified and compared with an exact solution and experimental data from the literature. Regarding the fixed boundary, the numerical results converge to the exact solution. Regarding the free interface, the numerical solutions were compared with the average height of the PCL in non-cystic fibrosis (CF) human tissues and were in excellent agreement. This research also proposes possible values of parameters in the mathematical model in order to determine the free interface. Applications of these fluid flows include animal hair, fibers and filter pads, and rice fields.

scholarly journals Mathematical Analysis of an Autoimmune Diseases Model: Kinetic Approach

Mathematics ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 1024 ◽  
Author(s):  
Mikhail Kolev
Keyword(s):  
Mathematical Model ◽  
Autoimmune Disease ◽  
Kinetic Theory ◽  
Autoimmune Diseases ◽  
Functional State ◽  
Mathematical Analysis ◽  
Numerical Results ◽  
Kinetic Approach ◽  
Basic Information ◽  
View Point

A new mathematical model of a general autoimmune disease is presented. Basic information about autoimmune diseases is given and illustrated with examples. The model is developed by using ideas from the kinetic theory describing individuals expressing certain functions. The modeled problem is formulated by ordinary and partial equations involving a variable for a functional state. Numerical results are presented and discussed from a medical view point.

scholarly journals Large-eddy simulation of a bi-periodic turbulent flow with effusion

2008 ◽  
Vol 598 ◽  
pp. 27-65 ◽  
Author(s):  
S. MENDEZ ◽  
F. NICOUD
Keyword(s):  
Turbulent Flow ◽  
Film Cooling ◽  
Large Scale ◽  
Cumulative Effect ◽  
Streamwise Velocity ◽  
Numerical Results ◽  
Computational Domain ◽  
Viscous Effects ◽  
Viscous Shear ◽  
Large Eddy

Large-eddy simulations of a generic turbulent flow with discrete effusion are reported. The computational domain is periodic in both streamwise and spanwise directions and contains both the injection and the suction sides. The blowing ratio is close to 1.2 while the Reynolds number in the aperture is of order 2600. The numerical results for this fully developed bi-periodic turbulent flow with effusion are compared to available experimental data from a large-scale spatially evolving isothermal configuration. It is shown that many features are shared by the two flow configurations. The main difference is related to the mean streamwise velocity profile, which is more flat for the bi-periodic situation where the cumulative effect of an infinite number of upstream jets is accounted for. The necessity of considering both sides of the plate is also established by analysing the vortical structure of the flow and some differences with the classical jet-in-crossflow case are highlighted. Finally, the numerical results are analysed in terms of wall modelling for full-coverage film cooling. For the operating point considered, it is demonstrated that the streamwise momentum flux is dominated by non-viscous effects, although the area where only the viscous shear stress contributes is very large given the small porosity value (4%).

Experimental Validation of a Dynamic Model for Flexible Link Mechanisms

2001 ◽  
Author(s):  
R. Caracciolo ◽  
A. Gasparetto ◽  
A. Trevisani
Keyword(s):  
Mathematical Model ◽  
Experimental Validation ◽  
Numerical Results ◽  
Test Case ◽  
Planar Mechanisms ◽  
Transient Period ◽  
Element Approach ◽  
Multi Body ◽  
The Mathematical Model ◽  
Good Agreement

Abstract This paper presents an experimental validation of a finite element approach for the dynamic analysis of flexible multi-body planar mechanisms. The mathematical model employed accounts for mechanism geometric and inertial non-linearities and considers coupling effects among rigid-body and elastic motion. A flexible five-bar linkage actuated by two electric motors is employed as a test case. Experimentally determined link absolute deformations are compared with the numerical results obtained simulating the system dynamic behavior through the mathematical model. The experimental and numerical results are in good agreement especially after the very first transient period.

Mathematical Modeling of Capillary Pumping Within Micron Sized Channels

2013 ◽  
Author(s):  
Yuelei Yang ◽  
Dan Zhang
Keyword(s):  
Mathematical Modeling ◽  
Experimental Data ◽  
Mathematical Model ◽  
Capillary Pressure ◽  
Heat Engine ◽  
Velocity Profiles ◽  
Vof Method ◽  
Numerical Results ◽  
Micro Heat Engine ◽  
Volume Of Fluids

This paper introduces a mathematical model which can be used to simulate the capillary pumping process of a micro heat engine. The micro heat engine has micron sized channels where the capillary pumping occurs. The classic Volume of Fluids (VOF) method is applied to obtain the velocity profiles of the fluids and to track the motions of the liquid-gas interfaces. The numerical results based this model have been compared with the experimental data and the initial retard of the pumping has been found and this phenomenon can be explained by the initial capillary pressure build-ups across the liquid-gas interfaces.

Characterization and Mathematical Modelling of Geometric Effects on Piezoelectric Actuators

2019 ◽  
Vol 201 (1) ◽  
pp. 201-217
Author(s):  
Hareem Jawaid ◽  
Waqar Ahmed Qureshi ◽  
Riffat Asim Pasha ◽  
Rizwan Ahmed Malik
Keyword(s):  
Mathematical Model ◽  
Structural Analysis ◽  
Mathematical Modelling ◽  
Piezoelectric Actuator ◽  
Piezoelectric Actuators ◽  
Numerical Results ◽  
Hydraulic Valves ◽  
Geometric Effects

This paper focuses on the characterization and static structural analysis of piezoelectric actuator to investigate the sequential increasing effect of piezoelectric patches. The effect on the tip deflection is observed analytically, numerically and experimentally. By varying the quantity and the geometry of piezoelectric patches/beams, the actuation effect is analyzed. A mathematical model has been developed for the unequal lengths of patches and beam. The analysis is carried out numerically to examine the tip deflection under various parameters. The results are analyzed and verified experimentally. The results are found to be in accordance with the analytical and numerical results. This permits the desired configuration of an actuator in applications like hydraulic valves for actuating and controlling the flow of liquid as per need.

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