Comparative Study of Heat Transfer Parameter Estimation Using Inverse Heat Transfer Models of a Trailing Liquid Nitrogen Jet in Welding
TL;DR: In this paper, an inverse heat transfer (IHT) method is adapted to estimate the heat transfer parameters due to heat sink in a tungsten inert gas welding apparatus on a low carbon steel wireframe.
Abstract: Welding induces distortions and stresses in welded structures. A heat sink trailing the weld arc is one among the methods used to reduce the stresses and distortions. Researchers have made use of cooling agents like atomized water and liquid nitrogen (LN2) jet as trailing heat sinks. As the inclusion of a heat sink alters the temperature distribution, estimation of heat removal due to cooling jet is a prerequisite for the study of the effects of the heat sink on stresses and distortions. Analytical methods for the estimation of heat transfer parameters are complicated due to nonuniform cooling by the impinging jet, boiling heat transfer of cooling jet, stray fluid particles on the work-piece surface, and the sharp localized temperature gradient on the work piece due to weld heat input. Therefore, an inverse heat transfer (IHT) method is adapted to estimate the heat transfer parameters due to heat sink. Experiments were conducted using automated tungsten inert gas welding apparatus on a low-carbon steel wo...
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TL;DR: In this article, an inverse methodology was proposed to estimate the thermal efficiency of a Gas Tungsten Arch welding (GTAW) process as a time-dependent function, which was applied in lab-controlled experiments based on a Robust Project matrix.
14 citations
07 Sep 2020
TL;DR: In this article, the effect of liquid nitrogen on the circumferential distortion, weld penetration and delta-ferrite distribution in different welding zones was investigated using a metallurgical microscope.
Abstract: AISI 316 stainless steel (SS316) is an attractive material for industrial applications. Welding of this alloy can lead to severe distortion that often results in dimensional inaccuracies. With the help of specially designed fixture and clamping mandrels, tungsten inert gas (TIG) welding on SS316 pipes is employed to investigate the effect of liquid nitrogen on the circumferential distortion, weld penetration and delta-ferrite distribution in different welding zones. The experimental results reveal that the presence of trailing heat sink in TIG welded butt joint has almost zero distortion at a distance of 30 mm from the weld centerline and 64% decrement in residual circumferential distortion at the center of the weld bead. A metallurgical microscope is used to find the weld penetration, (fusion zone) FZ and (heat affected zone) HAZ. The results illustrate that increase in current and the presence of intensive cooling media yield deeper penetration in TIG welding. Liquid nitrogen (LN2) also constricts the FZ and HAZ. Instead of evaluating delta-ferrite contents using the ferrite number technique, a MATLAB® code for image processing is developed to evaluate the delta-ferrite distribution in the different regions of a single-pass weldment. Delta-ferrite contents are maximum in the presence of intensive cooling media near HAZ and increase with an increase in the current value. Hence, TIG welding with LN2 as trailing heat sink is the most suitable scheme to weld industrial pipes owing to its higher weld penetration, higher delta-ferrite contents and minimum circumferential distortion.
4 citations
01 Jan 2016
TL;DR: In this paper, an innovative methodology based on Time Traveling concept is proposed to regularize the Golden Section technique, which proved to be a first-class method to determine the thermal efficiency in a welding process.
Abstract: This work presents a global model to determine the time dependent thermal efficiency in a GTAW process. With the purpose of estimating the amount of heat delivered by the GTAW torch, a previously developed homemade C++ code was improved. The new model proposes the heat flux estimation through the Golden Section optimization with Temperature Moving Sensor technique. An innovative methodology based on Time Traveling concept is proposed to regularize the Golden Section technique. In order to test the capacity of the model to adapt to a range of conditions, a set of lab-controlled experiments were performed under different welding conditions based on a Robust Project matrix (Taguchi). The objective function was determined based on to the fourth power between the experimental and the calculated values. Moreover, the work also presents an analysis of the cooling rate of the process by convection and radiation. An empirical correlation based on the local Nusselt number for flat plates was used to estimate the local heat transfer coefficient. The proposed model proved to be a first-class method to determine the thermal efficiency in a welding process.
1 citations
Cites methods from "Comparative Study of Heat Transfer ..."
...The thermal conductivity and diffusivity curves were built from fitting data presented in Touloukian et al. (1975). And the emissivity was taken from Roger et al....
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...Other authors only use tabulated literature values as Piekarska and Kubiak (2011), where they assume the laser-arc hybrid welding process efficiency as 75%, or Sudheesh and Prasad (2015) who applied an efficiency of 70% for a TIG welding process....
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TL;DR: In this article , the enhanced conjugate gradient method (ECGM) was applied to determine the peripheral variation of heat flux at the fluid-solid interface of a tube at a section downstream to the T-junction.
Abstract: Abstract In this paper, the Jaya algorithm is coupled with the traditional conjugate gradient method (CGM) for solving the inverse heat transfer problem. The coupling of two algorithms is termed as enhanced conjugate gradient method (ECGM). Two different applications have been considered to determine the accuracy and stability of ECGM. First, the algorithm is applied in a steady-state two-dimensional laminar flow through a duct for the boundary heat flux estimation. The accuracy of estimation has been compared with traditional CGM by calculating the root mean square (RMS) error. The ECGM algorithm (RMS =0.142 kW/m2) is found to be more accurate than conventional CGM (RMS = 0.198 kW/m2). ECGM is then applied to determine the peripheral variation of heat flux at the fluid-solid interface of a tube at a section downstream to the T-junction. The experimental temperature readings at the outer periphery of the tube required in the inverse algorithm are simulated by solving the direct heat conduction problem. Here, the heat flux at the fluid-solid interface is obtained by solving the governing equations of the turbulent flow by using commercial computational fluid dynamics software. ECGM is found to be a stable and accurate inverse heat transfer algorithm.
01 Jan 2021
TL;DR: In this paper, an estimation strategy for the film transfer coefficient by solving an inverse heat transfer problem via the Cuckoo Search global optimization algorithm was proposed, which showed great estimations for signal-to-noise ratios above 30 dB, which can be reached with virtually any modern temperature sensors.
Abstract: Film transfer coefficient is one of the most challenging variables to measure in experimental heat transfer. This happens because such a variable depends on too many others. Examples include type of media (gas or liquid), body geometry, fluid flow, thermal conductivity, and many more thermodynamic properties. In chapter proposes an estimation strategy for the film transfer coefficient by solving an inverse heat transfer problem via the Cuckoo Search global optimization algorithm. The designs were achieved through the entropy generation minimization criterion, also powered by Cuckoo Search, employing several specifications (material, working fluid and heat power). Obtained results show great estimations for signal-to-noise ratios above 30 dB, which can be reached with virtually any modern temperature sensors.
References
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Book•
01 Jan 2000TL;DR: Inverse heat transfer: Fundamentals and Applications, Second Edition as mentioned in this paper includes techniques within the Bayesian framework of statistics for the solution of inverse problems and their applications for solving problems in convective, conductive, radiative, and multi-physics problems.
Abstract: This book introduces the fundamental concepts of inverse heat transfer solutions and their applications for solving problems in convective, conductive, radiative, and multi-physics problems. Inverse Heat Transfer: Fundamentals and Applications, Second Edition includes techniques within the Bayesian framework of statistics for the solution of inverse problems. By modernizing the classic work of the late Professor M. Necati Ozisik and adding new examples and problems, this new edition provides a powerful tool for instructors, researchers, and graduate students studying thermal-fluid systems and heat transfer.
FEATURES
Introduces the fundamental concepts of inverse heat transfer
Presents in systematic fashion the basic steps of powerful inverse solution techniques
Develops inverse techniques of parameter estimation, function estimation, and state estimation
Applies these inverse techniques to the solution of practical inverse heat transfer problems
Shows inverse techniques for conduction, convection, radiation, and multi-physics phenomena
M. Necati Ozisik (1923–2008) retired in 1998 as Professor Emeritus of North Carolina State University’s Mechanical and Aerospace Engineering Department.
Helcio R. B. Orlande is a Professor of Mechanical Engineering at the Federal University of Rio de Janeiro (UFRJ), where he was the Department Head from 2006 to 2007.
933 citations
"Comparative Study of Heat Transfer ..." refers methods in this paper
...The method is an iterative technique that minimizes a cost function S(p) consisting of the sum of squares of difference in experimental and analytical values at corresponding time instants [13]....
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TL;DR: In this article, the authors investigated the effects of solid-state phase transformation on welding residual stress and distortion in low carbon and medium carbon steels, based on a sequentially coupled thermal, metallurgical, mechanical 3-D finite element model.
463 citations
"Comparative Study of Heat Transfer ..." refers background in this paper
...The variation of thermal properties such as thermal conductivity, specific heat, and density with temperature is shown in Figure 6 [14]....
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Book•
01 Jan 2005
TL;DR: In this article, a computer simulation of Welding Processes is presented, where the evolution of microstructure depending on temperature and deformation of the Welded Structures and applications of welding in Industrial Fields.
Abstract: Computer Simulation of Welding Processes.- Thermal Analysis of Welds.- Evolution of Microstructure Depending on Temperature.- Evolution of Microstructure Depending on Deformations.- Carburized and Hydrogen Diffusion Analysis.- Welded Structures and Applications of Welding in Industrial Fields.- Fracture Mechanics.- Input Data for Computational Welding Mechanics.
435 citations
TL;DR: In this article, liquid nitrogen (LN2) is applied to cutting Ti-6Al-4V, a difficult-to-machine but widely used material in aerospace industry.
Abstract: Cryogenic machining is an environmentally safe alternative to conventional emulsion cooling. In this study, liquid nitrogen (LN2) is applied to cutting Ti-6Al-4V, a difficult-to-machine but widely used material in aerospace industry. With the goal of identifying the cooling approach for most effectively and economically using cryogenic machining, this study evaluated cutting temperatures obtained under various cooling conditions. In addition to analyzing cooling approaches reported in previous cryogenic machining literatures (i.e., precooling the workpiece and conductive remote cooling), this paper introduces an innovative and economical dispensing method that directs LN2 through micro jets to the flank, the rake, or both near the cutting edge. The cutting temperatures were theoretically estimated by finite element method and the influence of cutting speed was analyzed. They were experimentally verified using the thermocouple imbedded at the carbide insert. Temperatures in cryogenic machining were compared with conventional dry cutting and emulsion cooling. Findings showed that a small amount of liquid nitrogen applied locally to the cutting edge is superior to emulsion cutting in lowering the cutting temperature. The study found that cooling approaches in order of effectiveness (worst to best) to be: dry cutting, cryogenic tool back cooling, emulsion cooling, precooling the workpiece, cryogenic flank cooling, cryogenic rake cooling, and simultaneous rake and flank cooling.
367 citations
"Comparative Study of Heat Transfer ..." refers background in this paper
...manufacturing processes like cutting with the aim of improving tool life [6, 7]....
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TL;DR: In this article, the role of cryogenic cooling by liquid nitrogen jet on cutting temperature in turning plain carbon steel (C-40) under varying cutting velocity and feed was investigated, and the experimental and computational results indicated that such cryogenic cooling enables substantial reduction in the cutting temperature depending upon the levels of the cutting speeds and feed and the cutting tool geometry.
Abstract: Application of conventional cutting fluids do not serve the purposes effectively particularly under high cutting velocity and feed. Besides, such cutting fluids pollute the environment in high production machining and grinding. Cryogenic cooling seemed to be quite effective in reducing the high cutting temperature which impairs product quality and reduces tool life. The present work deals with investigating the role of cryogenic cooling by liquid nitrogen jet on cutting temperature in turning plain carbon steel (C-40) under varying cutting velocity and feed. The experimental and computational results indicate that such cryogenic cooling enables substantial reduction in the cutting temperature depending upon the levels of the cutting velocity and feed and the cutting tool geometry. It was also noted that the chip formation and chip-tool interaction become more favorable and the cutting forces decreased to some extent when liquid nitrogen jet was employed. Therefore, it appears that cryogenic cooling, if properly employed, not only provides environment friendliness but can also improve the machinability characteristics.
100 citations