Comparative RANS turbulence modelling of lost salt core viability in high pressure die casting


Kohlstädt, Sebastian

KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.

Vynnycky, Michael

KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.ORCID iD: 0000-0002-8318-1251

Neubauer, Alexander

Volkswagen AG, Div Components Mfg, Business Unit Casting, Dr Rudolf Leiding Pl 1, D-34225 Baunatal, Germany..

Gebauer-Teichmann, Andreas

Volkswagen AG, Div Components Mfg, Business Unit Casting, Dr Rudolf Leiding Pl 1, D-34225 Baunatal, Germany..

Abstract 

In this work, the implementation of three turbulence models inside the open source C++ computational fluid dynamics (CFD) library OpenFOAM were tested in 2D and 3D to determine the viability of salt cores in high pressure die casting. A finite-volume and volume of fluid approach was used to model the two-phase flow of molten metal and air, with the latter being treated as compressible. Encouragingly, it is found that, although the choice of turbulence model seems to affect the dispersion of the two-phase interface, the force acting at the surface of the salt core depends only very weakly on the turbulence model used. The results were also compared against those obtained using the commercially available and widely-used casting software MAGMA(5).

Korea Abstract

이 작업에서 오픈 소스 C++ CFD(Computational Fluid Dynamics) 라이브러리 OpenFOAM 내부의 세 난류 모델 구현을 2D 및 3D로 테스트하여 고압 다이 캐스팅에서 염심의 생존 가능성을 결정했습니다. 유한 체적 및 유체 체적 접근법은 용융 금속 및 공기의 2상 유동을 모델링하는 데 사용되었으며 후자는 압축성으로 처리됩니다. 고무적으로, 난류 모델의 선택이 2상 계면의 분산에 영향을 미치는 것처럼 보이지만 염심 표면에 작용하는 힘은 사용된 난류 모델에 매우 약하게만 의존한다는 것이 발견되었습니다. 결과는 또한 상업적으로 이용 가능하고 널리 사용되는 주조 소프트웨어 MAGMA(5)를 사용하여 얻은 결과와 비교되었습니다.

Figure 2 CAD model of the sample geometry in 3D (see online version for colours)
Figure 2 CAD model of the sample geometry in 3D (see online version for colours)
Figure 9 Time evolution of the melt flow in the mid-cross section during mould filling, as calculated using OpenFOAM (see online version for colours)
Figure 9 Time evolution of the melt flow in the mid-cross section during mould filling, as calculated using OpenFOAM (see online version for colours)
Figure 10 Comparison of time evolution of the melt flow in the mid-cross section during mould filling, as calculated with OpenFOAM (upper row) and MAGMA5 (lower row), at four different times: (a) 0.1022 s (b) 0.1030 s (c) 0.1038 s (d) 0.1046 s (see online version for colours)
Figure 10 Comparison of time evolution of the melt flow in the mid-cross section during mould filling, as calculated with OpenFOAM (upper row) and MAGMA5 (lower row), at four different times: (a) 0.1022 s (b) 0.1030 s (c) 0.1038 s (d) 0.1046 s (see online version for colours)

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