scholarly journals Modeling of Eddy Current Welding of Rail: Three-Dimensional Simulation

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 947 ◽  
Author(s):  
Xiankun Sun ◽  
He Liu ◽  
Wanqing Song ◽  
Francesco Villecco
Keyword(s):  
Numerical Simulation ◽  
Heat Treatment ◽  
Eddy Current ◽  
Magnetic Induction ◽  
Three Dimensional ◽  
Heating Process ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Weak Formulation

In this paper is given a three-dimensional numerical simulation of the eddy current welding of rails where the longitudinal two directions are not ignored. In fact, usually it is considered a model where, in the two-dimensional numerical simulation of rail heat treatment, the longitudinal directions are ignored for the magnetic induction strength and temperature, and only the axial calculation is performed. Therefore, we propose the electromagnetic-thermal coupled three-dimensional model of eddy current welding. The induced eddy current heat is obtained by adding the z-axis spatial angle to the two-dimensional electromagnetic-thermal, thus obtaining some new results by coupling the numerical simulation and computations of the electric field and magnetic induction intensity of the three-dimensional model. Moreover, we have considered the objective function into a weak formulation. The three-dimensional model is then meshed by the finite element method. The electromagnetic-thermal coupling has been numerically computed, and the parametric dependence to the eddy current heating process has been fully studied. Through the numerical simulation with different current densities, frequencies, and distances, the most suitable heat treatment process of U75V rail is obtained.

Numerical Simulation of the Aerodynamics and Aerothermal Heating for a Hypersonic Vehicle

2012 ◽  
Vol 429 ◽  
pp. 147-153
Author(s):  
Hai Yong Liu ◽  
Hong Fu Qiang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Mach Number ◽  
Thermal Environment ◽  
Three Dimensional ◽  
Hypersonic Vehicle ◽  
Attack Angle ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model

A hypersonic forebody based on waverider and liftbody concept was presented. The configuration of a new hypersonic vehicle was designed by taking the configuration of X43A. Numerical simulation was conducted on the two-dimensional and three-dimensional models of the vehicle using CFD software of Gambit and Fluent. The effects of Mach number and attack angle on the aerodynamics and heat transfer were considered. The results of simulation investigation showed that: High compressed air was constrained beneath the pre-compressed surface of the forebody. The computational data on central cross section of the three-dimensional model for the vehicle was similar to that of the two-dimensional model. But great pressure gradient existed between the pre-compressed surface and side surface of the forebody which would lead to severe air leakage and pressure loss. The increasing of attack angle and Mach number enforced the stagnation of shock wave on the side walls of the engine. The thermal environment of the vehicle was deteriorated rapidly with increasing Mach number. But the viscous heating was overrated which lead to unbelievable high temperature. The software Fluent was more suitable to predict the aerodynamics than the heat transfer for hypersonic flow.

Clinical experience of using virtual 3D modelling for pre and intraoperative guidance during robotic-assisted partial nephrectomy

2021 ◽  
pp. 205141582110002
Author(s):  
Lorenz Berger ◽  
Aziz Gulamhusein ◽  
Eoin Hyde ◽  
Matt Gibb ◽  
Teele Kuusk ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Partial Nephrectomy ◽  
Surgical Outcome ◽  
Prospective Cohort ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Robotic Assisted ◽  
Robotic Assisted Partial Nephrectomy

Objective: Surgical planning for robotic-assisted partial nephrectomy is widely performed using two-dimensional computed tomography images. It is unclear to what extent two-dimensional images fully simulate surgical anatomy and case complexity. To overcome these limitations, software has been developed to reconstruct three-dimensional models from computed tomography data. We present the results of a feasibility study, to explore the role and practicality of virtual three-dimensional modelling (by Innersight Labs) in the context of surgical utility for preoperative and intraoperative use, as well as improving patient involvement. Methods: A prospective study was conducted on patients undergoing robotic-assisted partial nephrectomy at our high volume kidney cancer centre. Approval from a research ethics committee was obtained. Patient demographics and tumour characteristics were collected. Surgical outcome measures were recorded. The value of the three-dimensional model to the surgeon and patient was assessed using a survey. The prospective cohort was compared against a retrospective cohort and cases were individually matched using RENAL (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, location relative to polar lines) scores. Results: This study included 22 patients. Three-dimensional modelling was found to be safe for this prospective cohort and resulted in good surgical outcome measures. The mean (standard deviation) console time was 158.6 (35) min and warm ischaemia time was 17.3 (6.3) min. The median (interquartile range) estimated blood loss was 125 (50–237.5) ml. Two procedures were converted to radical nephrectomy due to the risk of positive margins during resection. The median (interquartile range) length of stay was 2 (2–3) days. No postoperative complications were noted and all patients had negative surgical margins. Patients reported improved understanding of their procedure using the three-dimensional model. Conclusion: This study shows the potential benefit of three-dimensional modelling technology with positive uptake from surgeons and patients. Benefits are improved perception of vascular anatomy and resection approach, and procedure understanding by patients. A randomised controlled trial is needed to evaluate the technology further. Level of evidence: 2b

scholarly journals Research on Parametric Design of Hydraulic Retarder Based on Multi-Field Coupling of Heat, Fluid and Solid

2015 ◽  
Vol 9 (1) ◽  
pp. 58-64 ◽  
Author(s):  
Kuiyang Wang ◽  
Jinhua Tang ◽  
Guoqing Li
Keyword(s):  
Numerical Simulation ◽  
Parametric Design ◽  
Design Method ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Field Coupling ◽  
Sequential Coupling ◽  
Fluid Coupling ◽  
Hydraulic Retarder

In order to optimize the design method and improve the performance of hydraulic retarder, the numerical simulation of multi-field coupling of heat, fluid and solid is carried out to hydraulic retarder, based on the numerical computation and algorithm of heat-fluid coupling and fluid-solid coupling. The computation models of heat-fluid coupling and fluid-solid coupling of hydraulic retarder are created. The three dimensional model of hydraulic retarder is established based on CATIA software, and the whole flow passage model of hydraulic retarder is extracted on the basis of the three dimensional model established. Based on the CFD calculation and the finite element numerical simulation, the temperature field, stress field, deformation and stress state are analysised to hydraulic retarder in the state of whole filling when the rotate speed is 1600 r/min. In consideration of rotating centrifugal force, thermal stress and air exciting vibration force of blade surface, by using the sequential coupling method, the flow field characteristics of hydraulic retarder and dynamic characteristics of blade structure are analysised and researched based on multi-field coupling of heat, fluid and solid. These provide the theoretical foundation and references for parametric design of hydraulic retarder.

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