TY - CONF

T1 - Determination of transient heat transfer by cooling channel in high-pressure die casting using inverse method

AU - Bohacek, Jan

AU - Mraz, Krystof

AU - Hvozda, Jiri

AU - Lang, F

AU - Raudensky, Miroslav

AU - Vakhrushev, Alexander

AU - Karimi Sibaki, Ebrahim

AU - Kharicha, Abdellah

PY - 2024/6

Y1 - 2024/6

N2 - Complex shapes of aluminum castings are typically manufactured during the shortcycle process known as the high-pressure die casting (HPDC). High productivity is ensured byintroducing die cooling through a system of channels, die inserts or jet coolers. Die cooling canalso effectively help in reducing internal porosity in cast components. Accurate simulationsbased on sophisticated numerical models require accurate input data such as material properties,initial and boundary conditions. Although the heat is dominantly dissipated through die cooling,indicating the importance of knowing precise thermal boundary conditions, open literature lacksa detailed information about the spatial distribution of heat transfer coefficient. This studypresents an inverse method to determine accurate heat transfer coefficients of a die insert basedon temperature measurements in multiple points by 0.5 mm K-type thermocouples and asubsequent solution of the two-dimensional inverse heat conduction problem. The solver wasbuilt in the open-source CFD code OpenFOAM and the free library for nonlinear optimizationNLopt. The results are presented for the commonly used 10 mm die insert with a hemisphericaltip and coolant flow rates ranging from 100 l/h to 200 l/h. Heat transfer coefficients reach valueswell above 50 kW/m2K in the hemispherical tip, which is followed by a secondary peak and thena gradual drop to values around 1 kW/m2K further downstream.

AB - Complex shapes of aluminum castings are typically manufactured during the shortcycle process known as the high-pressure die casting (HPDC). High productivity is ensured byintroducing die cooling through a system of channels, die inserts or jet coolers. Die cooling canalso effectively help in reducing internal porosity in cast components. Accurate simulationsbased on sophisticated numerical models require accurate input data such as material properties,initial and boundary conditions. Although the heat is dominantly dissipated through die cooling,indicating the importance of knowing precise thermal boundary conditions, open literature lacksa detailed information about the spatial distribution of heat transfer coefficient. This studypresents an inverse method to determine accurate heat transfer coefficients of a die insert basedon temperature measurements in multiple points by 0.5 mm K-type thermocouples and asubsequent solution of the two-dimensional inverse heat conduction problem. The solver wasbuilt in the open-source CFD code OpenFOAM and the free library for nonlinear optimizationNLopt. The results are presented for the commonly used 10 mm die insert with a hemisphericaltip and coolant flow rates ranging from 100 l/h to 200 l/h. Heat transfer coefficients reach valueswell above 50 kW/m2K in the hemispherical tip, which is followed by a secondary peak and thena gradual drop to values around 1 kW/m2K further downstream.

KW - transient heat transfer

KW - high-pressure die casting

KW - HPDC

KW - CFD

U2 - 10.1088/1742-6596/2766/1/012197

DO - 10.1088/1742-6596/2766/1/012197

M3 - Paper

T2 - 9th edition of the European Thermal Sciences Conference

Y2 - 10 June 2024 through 13 June 2024

ER -