An efficient and accurate method for transient heat conduction in a periodic structure with moving heat sources

2019 ◽  
Vol 30 (3) ◽  
pp. 1318-1344
Author(s):  
Haichao Cui ◽  
Qiang Gao ◽  
Xiaolan Li ◽  
Huajiang Ouyang

Purpose This paper aims to propose an efficient and accurate method to analyse the transient heat conduction in a periodic structure with moving heat sources. Design/methodology/approach The moving heat source is modelled as a localised Gaussian distribution in space. Based on the spatial distribution, the physical feature of transient heat conduction and the periodic property of structure, a special feature of temperature responses caused by the moving heat source is illustrated. Then, combined with the superposition principle of linear system, within a small time-step, computation of results corresponding to the whole structure excited by the Gaussian heat source is transformed into that of some small-scale structures. Lastly, the precise integration method (PIM) is used to solve the temperature responses of each small-scale structure efficiently and accurately. Findings Within a reasonable time-step, the heat source applied on a unit cell can only cause the temperature responses of a limited number of adjacent unit cells. According to the above feature and the periodic property of a structure, the contributions caused by the moving heat source for the most of time-steps are repeatable, and the temperature responses of the entire periodic structure can be obtained by some small-scale structures. Originality/value A novel numerical method is proposed for analysing moving heat source problems, and the numerical examples demonstrate that the proposed method is much more efficient than the traditional methods, even for larger-scale problems and multiple moving heat source problems.

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Abid Ali Khan ◽  
Farzeen Shahid ◽  
Ihtzaz Qamar

Welding is a process of joining the similar or different metals. Improper welding process leads to inaccuracies and misalignments of structural members, causing high cost and delays in work. Therefore, it is essential to predict the temperature field during welding process. Different techniques can be used to predict the temperature field, which may lead to structure distortion. The present study aims to develop a finite element solver for transient heat conduction analysis. The final solution is calculated from the assumed solution and compared with the numerical computations. The solver is then modified for use of moving heat source. The modification comprise, change in governing equations with the inclusion of phase change. The moving heat source continuously increases the temperature during motion. When the heat source completes a pass, model is allowed to cool down in order to study the temperature distribution during cooling.


2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Haichao Cui ◽  
Qiang Gao ◽  
Xiaolan Li ◽  
Huajiang Ouyang

Abstract This paper proposes an efficient numerical method for transient heat conduction in a quasi-periodic structure with nonlinear defects. According to the physical features of transient heat conduction, a quasi-superposition principle for transient heat conduction in a quasi-periodic structure with nonlinear defects is presented, and then a new method is developed to separate the above nonlinear problem to be solved into a linear problem of a perfect periodic structure and nonlinear problems of some small-scale structures with defects. As the scale of nonlinear problem to be solved is significantly reduced and low computational resource is required, outstanding efficiency is achieved. Finally, a numerical example shows that the proposed method is effective and accurate.


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Zhicheng Hu ◽  
Zhihui Liu

This paper focuses on efficiently numerical investigation of two-dimensional heat conduction problems of material subjected to multiple moving Gaussian point heat sources. All heat sources are imposed on the inside of material and assumed to move along some specified straight lines or curves with time-dependent velocities. A simple but efficient moving mesh method, which continuously adjusts the two-dimensional mesh dimension by dimension upon the one-dimensional moving mesh partial differential equation with an appropriate monitor function of the temperature field, has been developed. The physical model problem is then solved on this adaptive moving mesh. Numerical experiments are presented to exhibit the capability of the proposed moving mesh algorithm to efficiently and accurately simulate the moving heat source problems. The transient heat conduction phenomena due to various parameters of the moving heat sources, including the number of heat sources and the types of motion, are well simulated and investigated.


Author(s):  
Abid Ali Khan ◽  
Farzeen Shahid ◽  
Ihtzaz Qamar

Welding is a process of joining the similar or different metals. Improper welding process leads to inaccuracies and misalignments of structural members, causing high cost and delays in work. Therefore, it is essential to predict the temperature field during welding process. Different techniques can be used to predict the temperature field, which may lead to structure distortion. The present study aims to develop a finite element solver for transient heat conduction analysis. The final solution is calculated from the assumed solution and compared with the numerical computations. The solver is then modified for use of moving heat source. The modification comprise, change in governing equations with the inclusion of phase change. The moving heat source continuously increases the temperature during motion. When the heat source completes a pass, model is allowed to cool down in order to study the temperature distribution during cooling.


Author(s):  
Yaqi Zhang ◽  
Vadim Shapiro ◽  
Paul Witherell

Abstract Many additive manufacturing (AM) processes are driven by a moving heat source. Thermal field evolution during the manufacturing process plays an important role in determining both geometric and mechanical properties of the fabricated parts. Thermal simulation of AM processes is challenging due to the geometric complexity of the manufacturing process and inherent computational complexity that requires a numerical solution at every time increment of the process. We propose a new general computational framework that supports scalable thermal simulation at path scale of any AM process driven by a moving heat source. The proposed framework has three novel ingredients. First, the path-level discretization is process-aware, which is based on the manufacturing primitives described by the scan path and the thermal model is formulated directly in terms of manufacturing primitives. Second, a spatial data structure, called contact graph, is used to represent the discretized domain and capture all possible thermal interactions during the simulation. Finally, the simulation is localized based on specific physical parameters of the manufacturing process, requiring at most a constant number of updates at each time step. The latter implies that the constructed simulation not only scales to handle three-dimensional (3D) printed components of arbitrary complexity but also can achieve real-time performance. To demonstrate the efficacy and generality of the framework, it has been successfully applied to build thermal simulations of two different AM processes, fused deposition modeling (FDM) and powder bed fusion (PBF).


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