Effects of surface roughness and processing parameters on heat transfer coefficient between polymer and cavity wall during injection molding

Liu, Yao; Gehde, Michael

doi:10.1007/s00170-015-7816-5

Cited by 18 publications

(25 citation statements)

References 17 publications

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“…Available at www.ThermalFluidsCentral.org slip in polybutadiene flows and Hatzikiriakos and Kalogerakis (1994) who also studied molten polymer wall slip. Wall slip in thermal polymer processing was considered by Liu and Gehde (2016) in which slip was shown to significantly modify temperature distribution in polymers. Saleem and Nadeem (2015) used optimal Homotopy analysis method (OHAM) for nonlinear boundary layer flow from a rotating cone with presence of slip and viscous dissipation effects.…”

Section: Frontiers In Heat and Mass Transfermentioning

confidence: 99%

Numerical Simulation of Slip Influence on Electric Conducting Viscoelastic Fluid Past an Isothermal Cylinder

Amanulla¹,

Nagendra²,

Reddy³

2018

Frontiers in Heat and Mass Transfer

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The present study deals with the computational analysis on an electrically conducting magneto viscoelastic fluid over a circular cylinder. Prescribed partial slip effects are also taken into account. The governing physical problem is tackled numerically by using the highly efficient and reliable Keller box algorithm. Impact of sundry physical parameters on physical quantities of interest are evaluated. The influence of Williamson viscoelastic fluid parameter, magnetic body force parameter, Thermal and velocity (hydrodynamic) slip parameters, stream wise variable and Prandtl number on thermos-fluid characteristics are studied graphically. The model is relevant to the simulation of magnetic polymer materials processing.

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Section: Frontiers In Heat and Mass Transfermentioning

confidence: 99%

Numerical Simulation of Slip Influence on Electric Conducting Viscoelastic Fluid Past an Isothermal Cylinder

Amanulla¹,

Nagendra²,

Reddy³

2018

Frontiers in Heat and Mass Transfer

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“…Some et al [ 6 ] established a rough interface TCR model that simultaneously correlates pressure and temperature and found that the model can reliably predict TCR even during polymer crystallisation at the contact interface. Liu et al [ 7 ] focused on evaluating the HTC between the polymer and the cavity wall and established a mathematical model to improve the simulation of cooling and crystallinity development, thereby improving the accuracy of injection moulding simulations to predict the mechanical properties and dimensional accuracy of injection-moulded parts. Zhou et al [ 8 ] analysed the relationship between TCR and cooling time by developing a three-dimensional transient cooling analysis module for injection moulds, and they constructed a TCR calculation model.…”

Section: Introductionmentioning

confidence: 99%

Wall Slip Behaviour of Polymers Based on Molecular Dynamics at the Micro/Nanoscale and Its Effect on Interface Thermal Resistance

Lou

Feng

2020

Polymers

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Taking the Poiseuille flow of a molten polymer in parallel plates as the research object and polymethyl methacrylate (PMMA) as the research material, an all-atom analysis model of the molecular dynamic flow of polymer macromolecules is established according to the Navier slip law. The effects of wall wettability and external pressure on the wall slip behaviour of polymer macromolecules, as well as the spatial evolution process of the entanglement–unentanglement process of polymer chains near the wall under different shearing effects, were studied. The interface thermal resistance rule was explored, and an interface thermal resistance model considering the wall slip behaviour was established. Finally, a micro-injection experiment was used to verify the validity and accuracy of the model. The results show that when the wall is hydrophobic, the polymer melt exhibits significant wall slip. As the external pressure increases, the wall slip speed and the slip length increase. However, after a certain pressure is exceeded, the growth rate of the slip length is basically zero. As the external pressure increases, the PMMA molecular chains gradually start to separate, the single molecular chain becomes untangled from the entangled grid, and the chain detaches from the wall after exceeding a certain threshold. Wall slip reduces the interface thermal resistance between the solid–liquid interface and enhances the interface heat transfer performance. The interface thermal resistance value calculated by molecular dynamics can more accurately reflect the heat conduction rule of the solid–liquid interface at the micro/nanoscale than that measured by the thermal resistance experiment, indicating that the micro/nano interface thermal resistance obtained by molecular dynamics simulation is reliable.

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“…By keeping this into view, the researchers of [10][11][12][13][14] analyzed the non-Newtonian fluid flow properties by considering the various flow geometries and different physical effects. Wall slip in thermal polymer processing was considered by Liu and Gehde [15] in which slip was shown to significantly modify temperature distribution in polymers. Hatzikiriakos and Mitsoulis [16] presented closed form solutions and finite element computations for wall slip effects on pressure drop of power law fluids in tapered dies.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigations on magnetic field modeling for Carreau non-Newtonian fluid flow past an isothermal sphere

Amanulla

Wakif

Boulahia

et al. 2018

J Braz. Soc. Mech. Sci. Eng.

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In the current study, the effects of radial magnetic field, slip and jump conditions on the steady two-dimensional free convective boundary layer flow over an external surface of an isothermal sphere for an electro-conductive polymer are numerically studied. It is assumed that the studied fluid has a non-Newtonian rheological behavior and follows the Carreau fluid model. In this investigation, the formulation of the Carreau fluid model has been used first time for describing the present boundary layer problem, and then the resulting partial differential equations are transformed to ordinary differential equations by using non-similarity transformations. The obtained ordinary differential equations are solved numerically by a well-known method named as Keller-Box method. The finding results show that a weak elevation in temperature is accompanied with the increase in the Carreau fluid parameter, whereas a significant acceleration in the flow is computed near the sphere surface. It is shown also that an increase in the thermal slip parameter allows to strongly decrease both the skin friction coefficient and the local Nusselt number. The skin friction coefficient is also depressed with increasing magnetic body force parameter. Moreover, it is observed that an increase in the momentum slip parameter allows to decrease the skin friction coefficient, whereas the local Nusselt number is reduced with the increase in the Carreau fluid parameter. It is found also that the skin friction coefficient is increased with greater stream-wise coordinate, whereas the local Nusselt number is reduced with the increase in this parameter.

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Effects of surface roughness and processing parameters on heat transfer coefficient between polymer and cavity wall during injection molding

Cited by 18 publications

References 17 publications

Numerical Simulation of Slip Influence on Electric Conducting Viscoelastic Fluid Past an Isothermal Cylinder

Numerical Simulation of Slip Influence on Electric Conducting Viscoelastic Fluid Past an Isothermal Cylinder

Wall Slip Behaviour of Polymers Based on Molecular Dynamics at the Micro/Nanoscale and Its Effect on Interface Thermal Resistance

Numerical investigations on magnetic field modeling for Carreau non-Newtonian fluid flow past an isothermal sphere

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