Predictions of misruns using three-phase coupled mold-filling and solidification simulations in low pressure turbine (LPT) blades

Jana, Sripati; Kättlitz, Oliver; Hediger, Fredy; Jakumeit, J.; Aguilar, Julio

doi:10.1088/1757-899x/33/1/012007

Cited by 9 publications

(4 citation statements)

References 5 publications

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“…An average global heat transfer coefficient (HTC) was applied, which was calibrated for such flow and heat transfer conditions. It was assumed that HTC values decrease as the melt loses momentum and due to air gap formation (see [13] for details). The shell was assumed to be porous and the gas was allowed to escape easily by a lower value of a = 100000 (b = 0, see Eq.…”

Section: Resultsmentioning

confidence: 99%

Simulation of Cold Shuts and Misruns in Centrifugal Casting of TiAl Low Pressure Turbine Blades

Jana

Jakumeit

Tiefers

et al. 2013

MSF

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In this work cold shuts and misruns in thin turbine blade test geometries are predicted using a three-phase mold filling and solidification simulation methodology applied to a centrifugal casting process of turbine blades. The methodology is based on a finite-volume method with arbitrary shaped polyhedral control volumes. The Volume-of-Fluid (VOF) approach has been used to capture the phase separation between gas, melt and solid. A High Resolution Interface Capturing (HRIC) scheme has been established to gain sharp interfaces between phases, mandatory for correct calculation of surface tension and wetting angle effects. An additional source term in the momentum equation based on Darcy-law for porous media and Kozeny-Carman relation for the permeability estimation was implemented to model the resistance of the dendrite network to the melt flow. A series of test blades with decreasing thickness has been simulated and cold shuts and misruns predicted at different locations, depending on the blade thickness. Casting trials show an excellent agreement between simulation prediction and experimental findings.

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Section: Resultsmentioning

confidence: 99%

Simulation of Cold Shuts and Misruns in Centrifugal Casting of TiAl Low Pressure Turbine Blades

Jana

Jakumeit

Tiefers

et al. 2013

MSF

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“…Simulation of the HPDC process is based on a multiphase simulation, which correctly treats both air and liquid melt as compressible fluid. The treatment of the air as a compressible gas phase enables the flow solver STAR-CCM+ [6]. The interface between air and melt is captured by a volume of fluid approach, a standard approach for describing interfaces in turbulent flow processes [17][18][19].…”

Section: Theorymentioning

confidence: 99%

“…Reduced melt flow due to solidification with increasing fraction solid is first calculated by a temperature dependent viscosity followed by a porous media approach before the melt flow is frozen entirely at high solids content. The multi-phase simulation approach was implemented in the flow solver STAR-CCM+ [5,6]. A comprehensive review of porosity modelling for casting processes was given by Stefanescu [7].…”

Section: Introductionmentioning

confidence: 99%

Combined defect prediction for large-area die-cast components using high-resolution multi-phase simulation

Jakumeit,

Behnken,

Laqua

et al. 2023

IOP Conf. Ser.: Mater. Sci. Eng.

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In the automotive industry there is a trend towards large components that are manufactured using high pressure die casting process (HPDC), in particular when many previously welded individual parts are to be replaced with one cast part to save costs and energy. In the case of large components, incipient solidification during mold filling cannot be ruled out. Casting defects due to cold running, air pockets and porosity cannot be separated spatially and temporally and influence each other. This stronger linking of the defects requires a realistic depiction of the casting process in the simulation, since the interactions between effects are more difficult to depict through approximations. The multi-phase approach presented here offers various options for this: The air is calculated as a compressible gas that is separated from the melt by a sharp boundary surface. Reduced melt flow due to solidification is represented by a porous media approach, followed by a complete flow stop at high solids. The formation of porosity due to volume shrinkage is coupled with a gas evaporation model. The multi-phase approach was validated by casting trials using a specially designed test geometry for thin-walled aluminum HPDC applications. First results of an industrial application are shown.

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“…Since these factors mutually interact during the casting, in order to model the complete process as realistically as possible, solutions which couple all relevant transport processes are needed. Most models reported in the literature have focused on heat transfer analysis [12][13][14][15], fluid flow and heat transfer analysis [16][17][18][19][20][21][22][23], and heat transfer and stress analysis [24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Numerical Method for Calculation of Complete Casting Processes—Part I: Theory

Teskeredzic

Demirdžić

Muzaferija

2015

Numerical Heat Transfer, Part B: Fundamentals

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This article presents a method for calculation of the complete casting process, including the pouring of the liquid metal into the mold, its solidification, the deformation of the solidified cast, the formation of airgaps between the cast and the mold and their influence on the heat transfer, and the residual stresses. An original phase-change procedure is developed, valid for an arbitrary number of pure metals and=or alloys. A collocated version of a segregated finite-volume method is used to calculate both the liquid metal flow and the deformations and stresses in solids.

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Predictions of misruns using three-phase coupled mold-filling and solidification simulations in low pressure turbine (LPT) blades

Cited by 9 publications

References 5 publications

Simulation of Cold Shuts and Misruns in Centrifugal Casting of TiAl Low Pressure Turbine Blades

Simulation of Cold Shuts and Misruns in Centrifugal Casting of TiAl Low Pressure Turbine Blades

Combined defect prediction for large-area die-cast components using high-resolution multi-phase simulation

Numerical Method for Calculation of Complete Casting Processes—Part I: Theory

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