scholarly journals THE ANALYSIS OF STOCHASTIC PROCESSES IN UNLOADINGTHE ENERGYWILLOW CUTTINGS FROM THE HOPPER

2019 ◽  
Vol 3 ◽  
pp. 249 ◽  
Author(s):  
Serhii Yermakov ◽  
Hutsol Taras ◽  
Krzysztof Mudryk ◽  
Krzysztof Dziedzic ◽  
Liudmyla Mykhailova
Keyword(s):  
High Performance ◽  
Continuous Phase ◽  
Navier Stokes ◽  
Theoretical Formula ◽  
Navier Stokes Equation ◽  
Friction Laws ◽  
Multiphase Systems ◽  
Discrete Phase ◽  
Two Phases ◽  
Woody Crop

The paper deals with the theoretical and experimental investigation of the main characteristics of woody crop cuttings unloading from the hopper. To create a variety of automated systems for material feed there is a need to ensure high performance selecting and unloading the material, in particular, it is of vital importance in designing machines for energy willow planting. The analysis of existing theories in mechanics of loose materials motion made it possible to identify the features of unloading the cuttings that narrowed the area of discussion. We will consider two half-planes located at angles to the horizontal plane as a model for hopper in pilot testing. It is analytically and experimentally determined that woody crops cuttings flow occurs according to dry friction laws and inverse-square law and the flow is normal in nature. The statically stable formation and dynamic arches that prevent the uniform and continuous unloading are in evidence. For the theoretical validation of results, we present a set of cuttings as the pseudo liquid that consists of two phases: a discrete phase formed by cuttings and the continuous phase (gaseous medium, air). Each of these phases in terms of the mechanics of multiphase systems is represented as a solid medium with certain characteristics. According to these assumptions, the process unloading of such structure from the hopper can be modelled on the basis of methods of hydrodynamics of multiphase systems. In such a case the field speeds of such pseudo liquid must satisfy the Navier-Stokes equation type. The analytical and empirical analysis of unloading the energy willow cuttings helps to prove theoretically the possibility of enhancing the process of planting till its full automation. As a result, the study gives the theoretical formula that evaluates the velocity of energy willow cuttings flow, the adequacy of which is partially tested in pilot experiments conducted by the authors of the paper in the process of creating the planting machine. Using the received data for further research will make it possible to take into account all the factors involved in unloading and bridging, which is important for examining and improving this process.

The Effects of Hydrodynamics Characteristics on Mass Transfer During Droplet Formation Using Computational Approach

2006 ◽  
Author(s):  
A. Javadi ◽  
M. Taeibi-Rahni ◽  
D. Bastani ◽  
K. Javadi
Keyword(s):  
Mass Transfer ◽  
Stokes Equations ◽  
Computational Simulation ◽  
Mass Transfer Rate ◽  
Droplet Formation ◽  
Continuous Phase ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Two Phases ◽  
Expansion Model

For the reason that flow expansion model (developed in our previous work) for evaluating mass transfer during droplet formation involves with manifest hydrodynamic aspects, in this research computational simulation of this phenomenon was done for characterization of hydrodynamics effects on the mass transfer during droplet formation. For this purpose, an Eulerian volume tracking computational code based on volume of fluid (VOF) method was developed to solve the transient Navier-Stokes equations for the axisymmetric free-boundary problem of a Newtonian liquid that is dripping vertically and breaking as drops into another immiscible Newtonian fluid. The effects of hydrodynamics effects on the mass transfer during droplet formation have been discussed in the three features, including: 1- The intensity of the interaction between two phases 2-The strength and positions of the main vorticities on the nozzle tip 3-The effects of local interfacial vorticities (LIV). These features are considered to explain the complexities of drop formation mass transfer between Ethyl Acetoacetate (presaturated with water) as an organic dispersed phase and water as continuous phase for two big and small nozzle sizes (0.023 and 0.047 cm, ID) which have different level of mass transfer rate particularly in first stages of formation time.

scholarly journals A Study of the Impact of Methanol, Ethanol and the Miller Cycle on a Gasoline Engine

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4847
Author(s):  
Luke Oxenham ◽  
Yaodong Wang
Keyword(s):  
High Performance ◽  
Gasoline Engine ◽  
Navier Stokes ◽  
Miller Cycle ◽  
Navier Stokes Equation ◽  
Efficiency Increase ◽  
And Performance ◽  
The Impact ◽  
Emission Output ◽  
Turbo Engine

This paper focuses on the investigation and optimisation of the Miller cycle, methanol, ethanol and turbocharging when applied to a high-performance gasoline engine. These technologies have been applied both individually and concurrently to test for potential compounding effects. Improvements have been targeted with regards to both emission output and performance. Also assessed is the capability of the engine to operate when exclusively powered by biofuels. This has been carried out numerically using the 1D gas dynamics tool ‘WAVE’, a 1D Navier–Stokes equation solver. These technologies have been implemented within the McLaren M838T 3.8L twin-turbo engine. The Miller cycle early intake valve close (EIVC) improved peak efficiency by 0.17% and increased power output at low and medium loads by 11%. Reductions of 6% for both NOx and CO were also found at rated speed. The biofuels achieved NOx and CO reductions of 60% and 96% respectively, alongside an efficiency increase of 2.5%. Exclusive biofuel use was found to be feasible with a minimum 35% power penalty. Applied cooperatively, the Miller cycle and biofuels were not detrimental to each other, compounding effects of a further 0.05% efficiency and 2% NOx improvements were achieved.

scholarly journals Gasification of spent pot-lining from the aluminum industry

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Isam Janajreh ◽  
Sherien Elagroudy ◽  
Chaouki Ghenai ◽  
Syed Shabbar Raza ◽  
Idowu Adeyemi ◽  
...  
Keyword(s):  
Molar Fraction ◽  
Equilibrium Analysis ◽  
Navier Stokes ◽  
Aluminum Production ◽  
High Fidelity ◽  
Navier Stokes Equation ◽  
Discrete Phase ◽  
The Aluminum Industry ◽  
Multiple Species ◽  
Gasification Efficiency

Abstract Aluminum production generates enormous spent pot lining (SPL) waste of around one million tons yearly, and these wastes are usually disposed in landfills. Hence, the technical feasibility of SPL gasification using both equilibrium and reactive high-fidelity modeling was evaluated in this study. Three SPL with different washing treatment, i.e., water (WWSPL), acid treated (ATSPL), and full treated (FTSPL, a combination of both water and acid washing) were used for the modeling. The equilibrium model considered twelve species, while the high-fidelity simulation was modeled with multiple species. Moreover, the high fidelity model is governed by the steady non-isothermal Navier–Stokes equation coupled with the discrete phase in Eulerian–Lagrangian scheme. The process metrics were assessed via the produced syngas fraction (CO/H2) and gasification efficiency (GE). The equilibrium analysis of WWSPL, ATSPL, FTSPL, respectively, resulted in GE of 40, 65, and 75%. The corresponding syngas molar fractions for CO and H2 were 0.804 and 0.178 at 1450 °C; 0.769 and 0.159 at 1100 °C; and 0.730 and 0.218 at 1150 °C. These results suggest the potentiality and feasibility of gasifying the treated SPL, which was considered in the high-fidelity. Although the results show different trend from equilibrium for the FTSPL gasification (i.e., small molar fraction of CO2 and H2O and high syngas fraction dominated by CO at 0.75 and 0.1 H2 at best GE of 70%), it re-emphasizes the potential of the gasification of FTSPL as recyclable/renewable energy source. Graphical abstract

scholarly journals Unstructured Grid Solutions for Incompressible Laminar Flow over a Circular Cylinder Using a Particular Finite Volume-Finite Element Method

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Mahdi Yousefifard ◽  
Parviz Ghadimi ◽  
Rahim Zamanian
Keyword(s):  
Laminar Flow ◽  
Circular Cylinder ◽  
High Performance ◽  
Unstructured Grid ◽  
Unstructured Grids ◽  
Control Volume ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Benchmark Problems ◽  
Navier Stokes Equation

A numerical modeling of a 2D Navier-Stokes equation by a particular vertex centered control volume framework on an unstructured grid is presented in this paper. Triangular elements are applied with an effective high performance fully coupled algorithm, to simulate incompressible laminar flow over a circular cylinder. The cell face velocities in the discretization of the continuity and momentum equations are calculated by a combined linear and momentum interpolation scheme, respectively, and their performances are compared. Flow analyses have been conducted based on various Reynolds numbers up to 200 for the steady and unsteady flows using structured and unstructured grids. The robustness and accuracy of the scheme in the unstructured mesh are proved using the benchmark problems of incompressible laminar flow over a circular cylinder at low and medium Reynolds numbers. Results have been compared with the structured grid results, both cases with equal cell numbers and same strategy for the mesh refinement. Current results display good agreement with the experimental values. Overall, it is shown that, using the suggested method for the current problem, unstructured grids are highly competitive with the structured grids.

scholarly journals Integrated Ground Motion and Tsunami Simulation for the 1944 Tonankai Earthquake Using High-Performance Supercomputers

2009 ◽  
Vol 4 (2) ◽  
pp. 118-126 ◽  
Author(s):  
Takashi Furumura ◽  
◽  
Tatsuhiko Saito
Keyword(s):  
Ground Motion ◽  
High Performance ◽  
Structural Model ◽  
Nankai Trough ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Integrated Simulation ◽  
Rupture Model ◽  
Tonankai Earthquake ◽  
Long Period Ground Motion

An integrated simulation of seismic wave and tsunami has been developed for mitigation of earthquake and tsunami disasters associated with large subduction-zone earthquakes occurring in the Nankai Trough. The ground motion due to the earthquake is firstly calculated by solving equation of motions with heterogeneous source-rupture model and 3-D heterogeneous subsurface structural model. Tsunami generation and propagation in heterogeneous bathymetry is then simulated by solving the 3-D Navier-Stokes equation. Ground motion and tsunami simulations are combined through an appropriate dynamic boundary condition at the sea floor. Thanks to supercomputers and efficient parallel computing, we are reproducing strong ground motion and tsunamis caused by the M8.0 Tonankai earthquake in the Nankai Trough in 1944. The visualized seismic wavefield and tsunami derived by integrated simulation provides a direct understanding of disasters associated with Nankai Trough earthquakes with the development of long-period ground motion in highly populated basins such as Tokyo, Osaka, and Nagoya and tsunamis striking along Japan’s Pacific Ocean coast.

Bending Behavior Analysis of Composite Girders with Concrete Filled Tubular Flange

2011 ◽  
Vol 250-253 ◽  
pp. 2534-2537 ◽  
Author(s):  
Chun Sheng Wang ◽  
Xiao Liang Zhai ◽  
Lan Duan ◽  
Bao Rui Li
Keyword(s):  
Mechanical Behavior ◽  
High Performance ◽  
Static Load ◽  
Steel Tube ◽  
Theoretical Formula ◽  
Composite Girder ◽  
Bending Capacity ◽  
Bending Behavior ◽  
Two Phases ◽  
Concrete Model

In order to study the bending capacity of steel and concrete composite girder with concrete filled tubular flange (SCCGCFTF), a formula for the ultimate bending capacity of normal section was proposed based on perfected elastic-plastic model for steel and restricted concrete model for inner high performance self-compacted concrete. Analysis result shows that the mechanical behavior under static load can be divided into two phases in accordance with confining effects. Confining effects strength of the concrete-filled steel tube flange was relation to the restriction effect coefficient ξ. The ratios of the calculated value to the experimental ultimate bending capacity were between 0.93 and 0.97. Therefore, the theoretical formula is relatively safe to calculate the ultimate bending capacity.

scholarly journals Effects of Blade Parameters on the Flow Field and Classification Performance of the Vertical Roller Mill via Numerical Investigations

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Chang Liu ◽  
Zuobing Chen ◽  
Weili Zhang ◽  
Chenggang Yang ◽  
Ya Mao ◽  
...  
Keyword(s):  
Flow Field ◽  
Pressure Difference ◽  
Continuous Phase ◽  
Classification Performance ◽  
Field Analysis ◽  
Discrete Phase Model ◽  
Roller Mill ◽  
Discrete Phase ◽  
Vertical Roller ◽  
Classification Efficiency

The vertical roller mill is an important crushing and grading screening device widely used in many industries. Its classification efficiency and the pressure difference determine the entire producing capacity and power consumption, respectively, which makes them the two key indicators describing the mill performance. Based on the DPM (Discrete Phase Model) and continuous phase coupling model, the flow field characteristics in the vertical roller mill including the velocity and pressure fields and the discrete phase distributions had been analyzed. The influence of blade parameters like the shape, number, and rotating speed on the flow field and classification performance had also been comprehensively explored. The numerical simulations showed that there are vortices in many zones in the mill and the blades are of great significance to the mill performance. The blade IV not only results in high classification efficiency but also reduces effectively the pressure difference in the separator and also the whole machine. The conclusions of the flow field analysis and the blade effects on the classification efficiency and the pressure difference could guide designing and optimizing the equipment structure and the milling process, which is of great importance to obtain better overall performance of the vertical roller mill.

scholarly journals An Incompressible Polymer Fluid Interacting with a Koiter Shell

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Dominic Breit ◽  
Prince Romeo Mensah
Keyword(s):  
Moving Boundary ◽  
Classical Model ◽  
Elastic Shell ◽  
Planck Equation ◽  
Navier Stokes ◽  
Flexible Shell ◽  
Navier Stokes Equation ◽  
Shell System ◽  
Forward Equation ◽  
Polymer Fluid

AbstractWe study a mutually coupled mesoscopic-macroscopic-shell system of equations modeling a dilute incompressible polymer fluid which is evolving and interacting with a flexible shell of Koiter type. The polymer constitutes a solvent-solute mixture where the solvent is modelled on the macroscopic scale by the incompressible Navier–Stokes equation and the solute is modelled on the mesoscopic scale by a Fokker–Planck equation (Kolmogorov forward equation) for the probability density function of the bead-spring polymer chain configuration. This mixture interacts with a nonlinear elastic shell which serves as a moving boundary of the physical spatial domain of the polymer fluid. We use the classical model by Koiter to describe the shell movement which yields a fully nonlinear fourth order hyperbolic equation. Our main result is the existence of a weak solution to the underlying system which exists until the Koiter energy degenerates or the flexible shell approaches a self-intersection.

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