scholarly journals Fluid-dynamic study of the behavior of the air inside a textile Stenter

2021 ◽  
Vol 2118 (1) ◽  
pp. 012006
Author(s):  
J W Parra ◽  
M B Quadri ◽  
D C Rodríguez
Keyword(s):  
Finite Element Method ◽  
Turbulence Model ◽  
Textile Industry ◽  
Fluid Dynamic ◽  
High Energy ◽  
Operating Conditions ◽  
The Finite Element Method ◽  
Dynamic Simulations ◽  
3D Geometry ◽  
High Energy Consumption

Abstract In the textile industry, drying is one of the most important processes. This process requires large investments and high energy consumption, which generates high costs for companies in this sector. In this work, a modeling of the behavior of the air was carried out in a textile Stenter, under real operating conditions through the development of fluid-dynamic simulations. For the computational modeling of the problem, a 3D geometry was constructed based on measurements taken from an injector of a textile Stenter. The standard k-ε turbulence model was used in the turbulent flow solution. The equations of the model were solved numerically using the finite element method. The standard k-ϵ turbulence model proved to be a model capable of reproducing the behavior of the air in the injectors of the textile Stenter.

Research of throwing areols of underground pipeline in permafrost

2021 ◽  
pp. 21-30
Author(s):  
T. S. Sultanmagomedov ◽  
◽  
R. N. Bakhtizin ◽  
S. M. Sultanmagomedov ◽  
T. M. Halikov ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Experimental Study ◽  
Finite Element ◽  
Strain State ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Loss Of Stability ◽  
Underground Pipeline ◽  
The Finite Element Method ◽  
Permafrost Thawing

Study is due to the possibility of loss of stability of the pipeline in the process of pumping a product with a positive operating temperature and the formation of thawing halos. The article presents the ways of solving the thermomechanical problem of pipeline displacement due to thawing. The rate of formation of a thawing halo is investigated depending on the initial temperatures of the soil and the pumped product. The developed monitoring system makes it possible to study the rate of occurrence of thawing halos in the process of pumping the product. An experimental study on the formation of thawing halos around the pipeline was carried out on an experimental model. A thermophysical comparative calculation of temperatures around the pipeline on a model by the finite element method has been carried out. Keywords: underground pipeline; permafrost; thawing halo; monitoring; operating conditions; stress–strain state.

scholarly journals Agustin de Betancourt’s Mechanical Dredger in the Port of Kronstadt: Analysis through Computer-Aided Engineering

2018 ◽  
Vol 8 (8) ◽  
pp. 1338 ◽  
Author(s):  
José Rojas-Sola ◽  
Eduardo De la Morena-De la Fuente
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
3D Model ◽  
Russian Empire ◽  
Computer Aided Engineering ◽  
Operating Conditions ◽  
The Finite Element Method ◽  
Safety Coefficient ◽  
Computer Aided ◽  
The Russian Empire

This article analyzes the first self-propelled floating dredging machine designed and executed by Agustín de Betancourt in 1810 to dredge the port of Kronstadt (Russia). With this objective, a study of computer-aided engineering (CAE) has been carried out using the parametric software Autodesk Inventor Professional, consisting of a static analysis using the finite element method, of the 3D model which is reliable under operating conditions. The results have shown that the system of inertia drums proposed by Betancourt manages to dissipate the tensions between the different elements, locating the highest stresses in the links of the bucket rosary, specifically at the point of contact between links. Similarly, the maximum displacements and the greatest deformations (always associated with these points of greater stress), are far from reaching the limits of breakage of the material used in its construction, as well as the safety coefficient of the invention, confirming that the mechanism was oversized, as was generally the case at the time. This analysis highlights the talent of the Spanish engineer and his mastery of mechanics, in an invention, the first of its kind worldwide, which served the Russian Empire for many years.

scholarly journals Forward osmosis (FO)-reverse osmosis (RO) hybrid process incorporated with hollow fiber FO

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
S.-J. Im ◽  
S. Jeong ◽  
A. Jang
Keyword(s):  
Reverse Osmosis ◽  
Hollow Fiber ◽  
Forward Osmosis ◽  
High Energy ◽  
Operating Conditions ◽  
Energy Costs ◽  
High Dilution ◽  
Volume Production ◽  
Seawater Reverse Osmosis ◽  
High Energy Consumption

AbstractCurrently, desalination is limited by high energy consumption and high operational and maintenance costs. In this study, a new concept of a hollow fiber forward osmosis (HFFO)-based infinity desalination process with minor environmental impacts (free-energy intake and no pretreatment or brine discharge) is suggested. To evaluate the concept, an element-scale HFFO was conducted in both conventional FO and pressure-assisted FO modes, simulating a submerged HFFO operation. In the HFFO test, the impacts of several operating conditions on the performance of the HFFO were investigated to select the best case. Based on these results, the energy costs were calculated and compared with those of a hybrid FO–seawater reverse osmosis (SWRO) process. The HFFO showed a high dilution rate of the draw solution (up to approximately 400%), allowing the downstream SWRO process to operate at 25 bar with the same permeate volume production (recovery rate of 60%). Consequently, the HFFO-based infinity desalination process has an annual energy revenue of 183.83 million USD, compared with a stand-alone two-stage RO process based on a 100,000 m3/day plant.

scholarly journals Computational fluid dynamic simulations for dispersion of nanoparticles in a magnetohydrodynamic liquid: a Galerkin finite element method

RSC Advances ◽  
2018 ◽  
Vol 8 (67) ◽  
pp. 38324-38335 ◽  
Author(s):  
M. Nawaz ◽  
Shafia Rana ◽  
Imran Haider Qureshi
Keyword(s):  
Finite Element Method ◽  
Physical Properties ◽  
Fluid Dynamic ◽  
Galerkin Finite Element Method ◽  
Dynamic Simulations ◽  
Ohmic Dissipation ◽  
Galerkin Finite Element ◽  
Metallic Particles ◽  
Dispersion Of Nanoparticles ◽  
Thermo Physical Properties

This investigation studies the effects of the thermo-physical properties of four types of nano-metallic particles on the thermo-physical properties of radiative fluid in the presence of buoyant forces and Joule heating (ohmic dissipation).

Influence of Mining Operating Conditions on Fault Behavior

2014 ◽  
Vol 59 (3) ◽  
pp. 691-704 ◽  
Author(s):  
Zbigniew Burtan ◽  
Andrzej Zorychta ◽  
Jerzy Cieślik ◽  
Dariusz Chlebowski
Keyword(s):  
Finite Element Method ◽  
Operating Conditions ◽  
Operating Parameters ◽  
The Finite Element Method ◽  
Mining Operations ◽  
Fault Behavior ◽  
Caving Zone ◽  
Energy Dissipated ◽  
The Impact ◽  
Impact Of Mining

Abstract This article concerns numerical modeling of the impact of mining operations on fault behavior, carried out on the basis of a calculation program based on the finite element method. The calculations and their graphic results related to the reactions of vertical discontinuity on the mining operations that run along its boundary under changing operating parameters, such as geometry of the field and direction of mining with respect to the fault, as well as the method of liquidation of the caving zone. The behavior of the fault was analyzed based on distributions in the plane of shear stress and slip, together with their range and energy dissipated due to friction. The results of numerical calculations made it possible to draw conclusions on the impact of faults and the impact of operating conditions of mining in their vicinity on the level of seismic hazard.

Flow Field Instability and Rotordynamic Impedances for an Open Impeller Centrifugal Pump in Transient Four-Quadrant Regimes

2020 ◽  
Author(s):  
Md Shujan Ali ◽  
Farzam Mortazavi ◽  
Alan Palazzolo
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Turbulence Model ◽  
Flow Direction ◽  
High Energy ◽  
Operating Conditions ◽  
Mesh Deformation ◽  
Pump Impeller ◽  
Transient Regimes ◽  
Dynamic Forces

Abstract The American Petroleum Institute (API) level 2 rotordynamic stability analysis requires determination of possible destabilization forces on a compressor or pump impeller. Dynamic forces in transient regimes are often excluded although a turbomachine impeller may experience transient operation intentionally or accidentally. The centrifugal pump head, flow direction, rotation and torque can be both positive and negative in transient regimes. For example, in a renewable energy application, pump flow direction and rotation are reversed to generate power from the imposed fluid head. The complete characteristics of a centrifugal pump correspond to all four quadrants (4Q) of operation, to encompass all possible operating conditions. It is required to understand centrifugal pump impeller dynamic forces and rotordynamic responses for all 4Q for design, fault diagnostic, instability analysis, upset conditions (such as water hammer, surge etc.) and for reliable operation of high energy density machines. In the open literature, whirling impeller rotordynamic analyses appears only for normal pump operation. Centrifugal pump dynamic forces, rotordynamic impedances and flow instabilities of an open impeller are reported for 4Q operating regimes in this paper. A transient Computational Fluid Dynamics (CFD)-based model is implemented which is applicable to nonaxisymmetric turbomachinery components, such as with a volute and/or vaned diffuser. Whirling motion of the impeller is modeled by imposing mesh deformation at the impeller walls. A phase modulated multi-frequency mesh deformation method is imposed for better numerical efficiency. Reynolds Averaged Navier-Stokes (RANS) equations with the Shear Stress Transport (SST) turbulence model along with a transitional bypass turbulence model are employed for the CFD solution. The results show the underlying flow field instability and stall cells responsible for the impedance shapes. Furthermore, the model is employed for determining the dependence of the outputs on specific speed to extract rotordynamic forces more efficiently. Impeller dynamic forces are found to scale with the size of the impeller for the same eccentricity ratio and the same flow coefficient. Strength of impeller rotating stalls has dependence on whirl frequency ratio.

Analysis of the Oil Squeezing Power Losses of a Spur Gear Pair by Mean of CFD Simulations

2012 ◽  
Author(s):  
Franco Concli ◽  
Carlo Gorla
Keyword(s):  
High Efficiency ◽  
Fluid Dynamic ◽  
Axial Direction ◽  
Spur Gear ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Main Concern ◽  
Power Losses ◽  
Dynamic Simulations ◽  
Gear Mesh

Efficiency is becoming more and more a main concern in the design of power transmissions and the demand for high efficiency gearboxes is continuously increasing. Also the new restrictive euro standards for the reduction of pollutant emissions from light vehicles impose to improve the efficiency of the engines but also of the gear transmissions. For this reason the resources dedicated to this goal are continuously increasing. The first step to improve efficiency is to have appropriate models to compare different design solutions. Even if the efficiency of transmissions is quit high if compared to the efficiency of the engines and appropriate models to predict the power losses due to gear meshing, to bearings and to seals already exist, in order to have a further improvement, some aspects like the power losses related to the oil churning, oil squeezing and windage are still to be investigated. These losses rise from the interaction between the moving or rotating elements of the transmission and the lubricant. In previous papers [39, 40, 41 43, 44], the authors have investigated the churning losses of planetary speed reducers (in which there is a relative motion between the “planets + planet carrier” and the lubricant). This report is focused on the oil squeezing power losses. This kind of losses is associated with the pumping of the oil at the gear mesh, where there is a contraction of the volume between the mating gears due to the rotation of them and a consequent overpressure. This overpressure implies a fluid flow primarily in the axial direction and this, for viscous fluids, means additional power losses and a decrease of the efficiency. In this work this phenomena has been studied by means of some CFD (computational fluid dynamic) simulations with a VOF (volume of fluid) approach. The influence of some operating conditions like the rotational speed and the lubricant temperature have been studied. The results of this study have been included in a model to predict the efficiency of the whole transmission.

Numerical and Experimental Study on a Microfluidic Concentration Gradient Generator for Arbitrary Approximate Linear and Quadratic Concentration Curve Output

2017 ◽  
Vol 16 (1) ◽  
Author(s):  
Xueye Chen ◽  
Zengliang Hu ◽  
Lei Zhang ◽  
Zhen Yao ◽  
Xiaodong Chen ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Concentration Gradient ◽  
Fluid Dynamic ◽  
Milling Machine ◽  
Microfluidic Chips ◽  
The Finite Element Method ◽  
Pmma Substrate ◽  
Concentration Gradients ◽  
Biochemical Engineering ◽  
Gradient Generator

AbstractThis work introduces a simple and versatile method for researching the concentration gradient generator (CGG) which can present the arbitrary approximate linear and quadratic concentration gradient curves output. The concentration gradients of arbitrary approximate linear curves with two inlets and arbitrary quadratic curves in the CGG with three inlets are obtained with the corresponding flow velocities. The CGG was simulated basing on the finite element method (FEM). The fluid-dynamic and mass-transport about the CGG was studied. Moreover, the feasibility of simulation was clearly verified by an experiment which two microfluidic chips of CGG on the PMMA substrate were processed using CNC engraving and milling machine. The paper successfully demonstrates the controllability of concentration gradient profiles in CGG with two inlets and three inlets. The study on the CGG can help the trends study of cell and molecule in different samples in the biochemical engineering.

scholarly journals Evaluation of Seal Effects on the Stability of Rotating Fluid Machinery

1995 ◽  
Vol 2 (2) ◽  
pp. 85-92
Author(s):  
T. Iwatsubo ◽  
B. C. Sheng
Keyword(s):  
Finite Element Method ◽  
Operating Conditions ◽  
Individual Contribution ◽  
Rotating Fluid ◽  
The Finite Element Method ◽  
Fluid Machinery ◽  
Dynamic Interactions ◽  
Multi Stage ◽  
The Stability ◽  
The Individual

The stability of typical rotating fluid machinery such as single and multi-stage pumps is evaluated by using the finite element method. The individual contribution of the impellers, bearings and seals to the stability and the dynamic interactions of these fluid elements are examined. Various types of bearings and seals, such as annular smooth, parallel grooved and damper seals, are compared for better rotor stability. The effect of the operating conditions on the stability is also investigated. The results show that rotor stability can be easily improved by replacing the unstable fluid elements.

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