Turbulent models of oil flow in a circular pipe with sudden enlargement

A phenomenological model to predict the multiphase diffusional decomposition of the austenite in low-alloy hypoeutectoid steels was adapted for welding conditions. The kinetics of phase transformations coupled with the heat transfer phenomena was numerically implemented using the Finite Volume Method (FVM) in a computational code. The model was applied to simulate the welding of a commercial type of low-alloy hypoeutectoid steel, making it possible to track the phase formations and to predict the volume fractions of ferrite, pearlite and bainite at the heat-affected zone (HAZ). The volume fraction of martensite was calculated using a novel kinetic model based on the optimization of the well-known Koistinen-Marburger model. Results were confronted with the predictions provided by the continuous cooling transformation (CCT) diagram for the investigated steel, allowing the use of the proposed methodology for the microstructure and hardness predictions at the HAZ of low-alloy hypoeutectoid steels.

/pdf/numerical-predictions-for-the-thermal-history-microstructure-yv3v4qo9gt.pdf

Numerical Predictions for the Thermal History, Microstructure and Hardness Distributions at the HAZ during Welding of Low Alloy Steels

The purpose of this study is the numerical analysis of energy loss coefficient in pipe contraction using ANSYS CFX software. To this end, the effect of the dimensionless parameters of Euler number, Reynolds number, and relative roughness on energy loss coefficient has been investigated and eventually an overall formula to determine the energy loss coefficient in these transitions has been provided. In order to solve the fluid turbulence equations in the pipe, standard K-Epsilon model has been used. For this purpose, first the geometry of pipe transitions was designed in 3-D, using Solid Works software, and then the transitions were meshed by ANSYS MESHING. The initial simulation of transitions including boundary conditions of outlet, inlet and wall, was carried out by a pre-processor called CFX-PRE. Furthermore, to solve the equations governing the fluid flow in the pipes (Navier-Stokes equations) the CFX-SOLVER was used. And finally, the results were extracted using a post-processor called CFD-POST. The results indicated that the energy loss coefficient, contrary to the findings of previous researchers, is not only related to transition geometry, but also is dependent on the Reynolds number, relative roughness of the wall and Euler number. By increasing the Reynolds Number and turbulence of fluid flow in transitions, the energy loss coefficient is reduced. Moreover, by increasing the relative roughness in the transition’s wall the energy loss coefficient is reduced. The increase in pressure fluctuation causes the increase of Euler number which leads to the linear increase of energy loss coefficient.

/pdf/numerical-analysis-of-energy-loss-coefficient-in-pipe-4vea8mkvzv.pdf

Numerical Analysis of Energy Loss Coefficient in Pipe Contraction Using ANSYS CFX Software

Introduction. Automation of obtaining design parameters of the part is the most important step in the integration of the design, process planning and manufacturing. The aim of this work is to obtain part parameters, the numerical values of which can be used in parametric calculations.
Materials and Methods. The work is the development of the concept of end-to-end design and technological parametrization in Computer-Aided Manufacturing. The theoretical research is based on the formal theory of data representation and processing, the set theory, and the theory of hierarchical multilevel systems. The software implementation was carried out in the Visual Studio C++ environment using KOMPAS-3D application program interface and the C3D geometric kernel application program interface.
Results. A method has been developed for obtaining the initial part parameters during the transfer of information from the design engineering Computer-Aided Manufacturing systems to the technological preparation of production. A logical data structure in a relational form was developed, which made it possible to eliminate redundancy and ensure the consistency of the presentation of part parameters, taking into account the priorities of the sources of design information. The software method is implemented as part of the commercial Computer-Aided Manufacturing system for the KOMPAS- 3D platform. Source parameters (metadata, material properties, annotation parameters, parametric variables) are extracted from the 3D-model using application program interface. Integration with the KOMPAS-3D materials directory has been implemented to obtain material properties.
Discussion and Conclusion. The obtaining of initial information about the part is the first step in the implementation of the end-to-end design and technological parameterization in the field of Computer-Aided Manufacturing. Due to the design and technological parameterization and associativity of the toolpath, a through technological project can be built when changes made by the designer to the part will be automatically transferred to the technological model and to the control program for the CNC machine. End-to-end parametrization is most efficiently used for parametrized parts that have several dimensional modifications. Further development of the technological parameterization is expected to focus on the tasks of the automatic workpiece selection, cutting tools and devices.

http://vestnik.mrsu.ru/content/pdf/19-3/02.pdf

Automation of Obtaining Parts Parameters for Tasks of Design-Technological Parametrization

The properties of the super duplex stainless steels (SDSS) are strongly affected by the thermal history imposed by welding procedures. The controlled dual phase microstructure (ferrite and austenite) guarantee excellent mechanical properties such as mechanical strength and corrosion resistance, in addition to small thermal expansion coefficient and high thermal conductivity. In this paper, we newly proposed a model able to predict the thermal history of the welding pieces coupled with local mechanical properties developed during welding procedure that combine the effects of temperature and phase changes during welding. We applied inverse method to fit the thermophysical parameters based on measured data. The model was verified by comparing measured and predicted temperature profiles using thermocouples located within the heat affected zone. Thus, an inverse method was implemented to obtain the parameters fitting for the grain growth evolution compatible with the final microstructure and grain size measured using SEM images and stereological techniques. We demonstrated that very small amount of non-equilibrium deleterious phases and nanosized precipitated are expected during the welding procedures depending upon the local conditions of temperature, compositions and alloying dilution evolutions.

/pdf/effects-of-local-heat-input-conditions-on-the-thermophysical-4zvipqniqt.pdf

Effects of Local Heat Input Conditions on the Thermophysical Properties of Super Duplex Stainless Steels (SDSS)

This paper describes an analytical approach to des cribe the areas where Pipes (used for flow of fluid s) are mostly susceptible to damage and tries to visualize the flow behaviour in various geometric conditions of a pipe. Fluent sof tware was used to plot the characteristics of the flow and gambit software was used to design the 2D model. Two phase Computation al fluid dynamics calculations, using K-epsilon model were employed. This simulation gives the values of pressure and ve locity contours at various sections of the pipe in which water as a media. A c omparison was made with the sudden and gradual chan ge of pipe diameter (i.e., expansion and contraction of the pipe). The numerical results were validated against experiment al data from the literature and were found to be in good agreement.

/pdf/comparison-of-flow-analysis-of-a-sudden-and-gradual-change-411n62nzjy.pdf

Comparison of flow analysis of a sudden and gradual change of pipe diameter using fluent software

GAS TUNGSTEN ARC WELDING (GTAW) is the quality weld process. It is preferred welding process for stainless steel, low alloy steel, nickel, cobalt, titanium, aluminum, copper, and magnesium. The present work aims to evaluate the effect of Gas Tungsten Arc Welding process parameters on the quality of the weld bead. The process parameters Welding Current, Wire Diameter, Wire Feed Speed, Ratio of wire feed rate to travel speed and Plate thickness are taken as a input variables for this present work. The quality of the weld bead can be assessed by the bead characteristics such as Penetration, Reinforcement & Width. Experiments were conducted to study the effects of the welding process parameters. Statistically designed experiments with 5 process parameters (each at 3 levels) are conducted to study the effect of these parameters on bead geometry. It is found from the analysis of variance (ANOVA) that the wire feed rate, travel speed and wire diameter are the main parameters that influence bead geometry in GTAW. Mathematical models are developed for depth of penetration, reinforcement height and bead width for GTAW using the multiple regression analysis. Index Terms: GTAW, DataFit version 9.0.59, I, D, WFR, TS, PT.

/pdf/development-of-mathematical-model-on-gas-tungsten-arc-va7uldf53g.pdf

Development of mathematical model on gas tungsten arc welding process parameters

Arc welding is one of the mostly used fabrication process in the industry due to its potent applications. During manual metal Arc Welding heat is transferred to the joint by melting an electrode. During welding process, the thermal stresses are generated in the specimen causing distortion and change in the shape. This problem of residual stresses and distortion of welded plates has become a major issue of research on shipbuilding and machine tool bodies. In the present work a corner welded joint has been used to simulate the Arc Welding process for the purpose of estimation of distortion and residual stresses. The simulation has been carried using a numerical technique Finite Element Method and with the commercial software ANSYS 11.0. The FEM has been carried in two stages. In the first stage, the pure thermal analysis is carried to estimate the time dependent temperatures. The temperatures obtained in thermal analysis are given as input in the second stage i.e. The Structural Analysis. The output of this thermo mechanical analysis involves estimation of Von mises Stresses, Strains and deformation.

https://www.ijert.org/research/thermo-mechanical-analysis-of-a-corner-welded-joint-by-finite-element-method-IJERTV1IS7399.pdf

Thermo-mechanical Analysis Of A Corner Welded Joint By Finite Element Method

Multi criteria optimization plays a very important role in product development. During The product concept phase, the designer decides a set of objectives tha t needs to be optimized. Every designer strives to ac hieve a utopian design that will optimize all the objecti ves. In real Life such a design is impossible to achieve. O ne of the reasons is the conflicting nature of Objectives that need to be optimized. The designer has to arrive at a compromised design that will satisfy the requiremen t to the greatest extent. Compromise involves tradeoffs between efficiency, cost, quality and other attribu tes. The method presented here shows the implementation of a multi-criteria optimization technique. Various techniques that are used are presented and later one of them is illustrated usin g a gear train optimization problem. Numerous solutions are obtained by the analysis and they all are optim al solutions. To choose between the designs is one of the difficult tasks and it depends on the designer’s judgment. There are available methods that provide valuable information about each design, and it help s the designer in making correct decision. The propos ed study incorporates one such decision technique. The approach provides valuable insight in solving real life design problems using multi-criteria optimization technique. This method can be a part of an expert system built for gear-train design.

/pdf/trade-of-analysis-for-helical-gear-reduction-units-4x3si7609w.pdf

Trade Of Analysis For Helical Gear Reduction Units

A hybrid laminate of carbon nanotubes effects on mechanical properties (tensile, flexural, and hardness) by changing the fiber orientation. In the present paper, fabrication of glass fiber reinforced of 1% CNT-based laminated composite with varying the orientation of reinforced fiber were prepared by hand layup technique on percentage of volume. Three different samples were fabricated by varying the orientation of woven-roving glass mat in parallel to fiber orientation, with angle 45° and with angle 135° to fiber direction. The study used to compare the effect of mechanical properties among the different orientations of fiber in order to improve the strength and toughness, fabrication is done by using E glass fiber of woven roving. The results of tensile strength, percentage of elongation, flexural strength, flexural modulus, and hardness of the composite were compared by statistical results and found to be in good agreement. However, the highest values, respectively, suggesting fiber orientation for effective and maximum stress transfer in laminated composite.

Fabrication and Characterization of CNT-Based Hybrid Composite

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

K. Ashok Kumar

Author Tools

Chat about Author