Numerical Simulation of Start-Up Jets in a Mixing Chamber

2010 ◽  
Author(s):  
Chenzhou Lian ◽  
Dmytro M. Voytovych ◽  
Guoping Xia ◽  
Charles L. Merkle
Keyword(s):  
Transient Flow ◽  
Three Dimensional ◽  
Cost Effective ◽  
Grid Refinement ◽  
Mixing Process ◽  
Quantitative Estimates ◽  
Start Up ◽  
Mixing Chamber ◽  
Parametric Analyses ◽  
Transient Mixing

Numerical simulations of a transient flow of helium injected into an established background flow of nitrogen were carried out to identify the dominant features of the transient mixing process between these two dissimilar gases. The geometry of interest is composed of two helium slots on either side of a central nitrogen channel feeding into a ‘two-dimensional’ mixing chamber. Simulations were accomplished on both two- and three-dimensional grids using an unsteady DES approach. Results are compared with experimental measurements of species distributions. Unsteady 2-D solutions give a reasonable qualitative picture of the transient mixing process in the middle of the chamber and enable cost-effective parametric analyses and grid refinement studies. The 2-D solutions also provide quantitative estimates of representative characteristic times to guide the 3-D calculations. The 3-D solutions give a reasonable approximation to span-wise events.

Numerical Simulation of Start-Up Jets in a Mixing Chamber

2011 ◽  
Vol 133 (7) ◽  
Author(s):  
Chenzhou Lian ◽  
Dmytro M. Voytovych ◽  
Guoping Xia ◽  
Charles L. Merkle
Keyword(s):  
Transient Flow ◽  
Three Dimensional ◽  
Mixing Process ◽  
Start Up ◽  
Mixing Chamber ◽  
Local Point ◽  
Contour Plots ◽  
Two Dimensional Flow ◽  
Reduced Dimension ◽  
Transient Mixing

Numerical simulations of the transient flow of helium injected into an established background flow of nitrogen were carried out to identify the dominant features of the transient mixing process between these two dissimilar gases. The geometry of interest is composed of two helium slots on either side of a central nitrogen channel feeding into a rectangular mixing chamber that was experimentally designed to give “two-dimensional” flow. Simulations were accomplished on both two- and three-dimensional grids. The 3D solutions employ an unsteady DES approach, while the 2D results are based upon a reduced dimension, “DES-like” method. Results are compared with quantitative experimental measurements of species distributions both in terms of contour plots and local point measurements. The 2D solutions give a reasonable qualitative picture of the transient mixing process in the center of the chamber while also providing quantitative estimates of representative characteristic times for guiding the 3D calculations. The 3D solutions give a reasonable approximation to span-wise variations observed in the experiment.

scholarly journals DETERMINATION OF ENERGY EFFICIENT LEVEL OF THE SPEED OF MIXING BODY OF ELECTROMECHANICAL SYSTEM

2020 ◽  
Vol 4 (52) ◽  
pp. 17-26
Author(s):  
N. Zablodskiy ◽  
◽  
М. Spodoba ◽  
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Electromechanical System ◽  
Main Process ◽  
Mixing Process ◽  
Start Up ◽  
Biogas Plants ◽  
Biogas Reactors

Purpose. Today, biomass fermentation in biogas plants is one of the most advanced, environmentally and economically viable solutions for energy production from waste. However, the process of anaerobic digestion of waste is long, so the main process of intensification is mixing. Analysis of well-known studies of domestic and foreign scientists indicates the urgency of reducing energy consumption for the mixing process. The aim of the study is to determine the energy-efficient speed of a paddle stirrer with blades set at an angle of 450 for small biogas reactors. Methodology. At the decision of the set tasks the general methods of physics, three-dimensional modeling, processing and visualization of the received results in the SolidWorks Flow Simulation and Wolfram Mathematica programs are applied. Results. Using 3D modeling, the influence of the stirrer speed on the picture of the distribution of the velocity vectors of the substrate flows in the biogas reactor was studied. Graphs of power consumption at the beginning of mixing for different stirrer speeds were obtained and analyzed, and the levels of energy consumed for mixing biomass during the start-up period and the whole mixing period were compared. A method for determining the energy efficient rotation speed of the stirring mechanism of the electromechanical system of biogas reactors is proposed. Practical value. The results can be used in the construction and modernization of biogas plants to reduce energy consumption of the substrate mixing process. Conclusion. Based on the research, it was concluded that for a paddle two-tier mixer with blades set at an angle of 450 energy-efficient speed, is 40 rpm. At this speed, careful and intensive mixing of the biomass is observed throughout the volume of the tank. The average velocity of flow vectors in the biomass volume is 0,273 m/s. The energy consumed per cycle of biomass mixing is 2471,3 J, and the percentage of energy consumed during the start-up period from the energy consumed during the entire mixing period is 0,62 %. References 19, figures 5.

An experience of elaboration and implementation of systems of slag-forming mixtures mechanized feeding into CCM moulds

2020 ◽  
Vol 76 (10) ◽  
pp. 994-1003
Author(s):  
S. P. Eron’ko ◽  
M. Yu. Tkachev ◽  
E. V. Oshovskaya ◽  
B. I. Starodubtsev ◽  
S. V. Mechik
Keyword(s):  
Economic Effect ◽  
Three Dimensional ◽  
Movable Part ◽  
High Quality ◽  
Working Zone ◽  
Fine Material ◽  
Mixing Chamber ◽  
Field Samples ◽  
Technical Solutions ◽  
Feeding Systems

Effective application of slag-forming mixtures (SFM), being fed into continuous castingg machine (CCM) moulds, depends on their even distribution on the melt surface. Manual feeding of the SFM which is widely usedd does not provide this condition, resulting in the necessity to actualize the work to elaborate systems of SFM mechanized feedingg into moulds of various types CCM. A concept of the designing of a system of SFM feeding into CCM moulds presented with the ratte strictly correspondent to the casting speed and providing formation of an even layer of fine material of given thickness on the whoole surface of liquid steel. The proposed methods of designing of the SFM mechanized feeding systems based on three-dimensional computer simulation with the subsequent verification of the correctness of the adopted technical solutions on field samples. Informattion is presented on the design features of the adjusted facilities intended for continuous supply of finely granulated and powder mixtuures on metal mirror in moulds at the production of high-quality billets, blooms and slabs. Variants of mechanical and pneumo-mechaanical SFM supply elaborated. At the mechanical supply the fine material from the feeding hopper is moved at a adjusted distance bby a rigid horizontally located screw. At the pneumo-mechanical supply the metered doze of the granular mixture is delivered by a sshort vertical screw, the lower part of which is located in the mixing chamber attached from below to the hopper and equipped with ann ejector serving for pneumatic supply of the SFM in a stream of transporting gas. It was proposed to use flexible spiral screws in the ffuture facilities of mechanical SFM feeding. It will enable to eliminate the restrictions stipulated by the lack of free surface for locatiion of the facility in the working zone of the tundish, as well as to decrease significantly the mass of its movable part and to decreaase the necessary power of the carriage moving mechanism driver. The novelty of the proposed technical solutions is protected by thhree patents. The reduction of 10–15% in the consumption of slag-forming mixtures during the transition from manual to mechanizeed feeding confirmed. The resulting economic effect from the implementation of technical development enables to recoup the costs inncurred within 8–10 months.

scholarly journals Cyber-Physical Systems Improving Building Energy Management: Digital Twin and Artificial Intelligence

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2338
Author(s):  
Sofia Agostinelli ◽  
Fabrizio Cumo ◽  
Giambattista Guidi ◽  
Claudio Tomazzoli
Keyword(s):  
Artificial Intelligence ◽  
Renewable Energy ◽  
Energy Management ◽  
Three Dimensional ◽  
Cost Effective ◽  
Automation System ◽  
Climate Conditions ◽  
Digital Twin ◽  
Building Energy Management ◽  
Computing Paradigm

The research explores the potential of digital-twin-based methods and approaches aimed at achieving an intelligent optimization and automation system for energy management of a residential district through the use of three-dimensional data model integrated with Internet of Things, artificial intelligence and machine learning. The case study is focused on Rinascimento III in Rome, an area consisting of 16 eight-floor buildings with 216 apartment units powered by 70% of self-renewable energy. The combined use of integrated dynamic analysis algorithms has allowed the evaluation of different scenarios of energy efficiency intervention aimed at achieving a virtuous energy management of the complex, keeping the actual internal comfort and climate conditions. Meanwhile, the objective is also to plan and deploy a cost-effective IT (information technology) infrastructure able to provide reliable data using edge-computing paradigm. Therefore, the developed methodology led to the evaluation of the effectiveness and efficiency of integrative systems for renewable energy production from solar energy necessary to raise the threshold of self-produced energy, meeting the nZEB (near zero energy buildings) requirements.

Trends in pediatric imaging: ultrasound

2013 ◽  
Vol 54 (9) ◽  
pp. 1096-1105 ◽  
Author(s):  
Ansgar Berg ◽  
Gottfried Greve
Keyword(s):  
Heart Diseases ◽  
Three Dimensional ◽  
Cost Effective ◽  
Clinical Work ◽  
Ventricular Volume ◽  
Tissue Doppler ◽  
Doppler Imaging ◽  
Strain And Strain Rate ◽  
2D Echocardiography ◽  
Systolic And Diastolic Function

For the last three decades, two-dimensional (2D) echocardiography and Doppler echocardiography have been the primary imaging modalities for the diagnosis and management of heart disease in infants, children, and adolescents. These methods are non-invasive, highly sensitive, and cost-effective, and widely available, making them very useful in clinical work. During this period, the anatomic and hemodynamic abnormalities associated with different congenital and acquired pediatric heart diseases have been well outlined by echocardiography. Recent advances in computer technology, signal processing, and transducer design have allowed the capabilities of pediatric echocardiography to be expanded beyond qualitative 2D imaging and blood flow Doppler analysis. New modalities such as three-dimensional echocardiography, tissue Doppler imaging and speckle tracking echocardiography have been used to evaluate parameters such as ventricular volume, myocardial velocity, regional strain, and strain rate, providing new insight into cardiovascular morphology and ventricular systolic and diastolic function. Accordingly, a comprehensive and sophisticated quantification of ventricular function is now part of most echocardiography protocols. Use of measurements adjusted for body size and age is common practice today. These developments have further strengthened the position of echocardiography in pediatric cardiology.

The Use of Photogrammetry in Piping Design

1983 ◽  
Vol 197 (2) ◽  
pp. 125-138 ◽  
Author(s):  
P A Bracewell ◽  
U R Klement
Keyword(s):  
Information Retrieval ◽  
Mathematical Formulation ◽  
Three Dimensional ◽  
Cost Effective ◽  
Process Industry ◽  
Process Plant ◽  
Definition Of ◽  
High Degree ◽  
Positional Data

Piping design for ‘revamp’ projects in the process industry requires the retrieval of large amounts of ‘as-built’ data from existing process plant installations. Positional data with a high degree of accuracy are required. Photogrammetry, the science of measurement from photographs, was identified in Imperial Chemical Industries plc (ICI) as a suitable tool for information retrieval. The mathematical formulation enabling the definition of three-dimensional positions from photographic information is described. The process of using ICI's photogrammetric system for the definition of complete objects such as structures and pipes is illustrated. The need for specialized photogrammetric software for design purposes is explained. A case study describing how the photogrammetric system has been applied is described and graphical outputs from this exercise are shown. It is concluded that this particular photogrammetric system has proved to be a cost effective and accurate tool for the retrieval of ‘as-built’ information.

scholarly journals Computation of Three-Dimensional, Rotational Flow Through Turbomachinery Blade Rows for Improved Aerodynamic Design Studies

1986 ◽  
Author(s):  
S. V. Subramanian ◽  
R. Bozzola ◽  
Louis A. Povinelli
Keyword(s):  
Three Dimensional ◽  
Maximum Flow ◽  
Cost Effective ◽  
Computer Code ◽  
Integration Scheme ◽  
Aerodynamic Design ◽  
Design Studies ◽  
Flow Equations ◽  
Transonic Compressor ◽  
Numerical Predictions

The performance of a three dimensional computer code developed for predicting the flowfield in stationary and rotating turbomachinery blade rows is described in this study. The four stage Runge-Kutta numerical integration scheme is used for solving the governing flow equations and yields solution to the full, three dimensional, unsteady Euler equations in cylindrical coordinates. This method is fully explicit and uses the finite volume, time marching procedure. In order to demonstrate the accuracy and efficiency of the code, steady solutions were obtained for several cascade geometries under widely varying flow conditions. Computed flowfield results are presented for a fully subsonic turbine stator and a low aspect ratio, transonic compressor rotor blade under maximum flow and peak efficiency design conditions. Comparisons with Laser Anemometer measurements and other numerical predictions are also provided to illustrate that the present method predicts important flow features with good accuracy and can be used for cost effective aerodynamic design studies.

Simple fabrication of a three-dimensional porous polymer film as a diffuser for organic light emitting diodes

Nanoscale ◽  
2014 ◽  
Vol 6 (23) ◽  
pp. 14446-14452 ◽  
Author(s):  
Byung Wan Lim ◽  
Min Chul Suh
Keyword(s):  
Polymer Film ◽  
Spin Coating ◽  
Three Dimensional ◽  
Cost Effective ◽  
Porous Polymer ◽  
Organic Light Emitting Diodes ◽  
Coating Process ◽  
Light Emitting ◽  
Organic Light ◽  
Ultrasonic Humidifier

We have investigated a simple and cost-effective fabrication method for a porous polymer film employing the spin-coating process during continuous supply of water droplets by an ultrasonic humidifier.

Sign in / Sign up

Export Citation Format

Share Document