The Experts below are selected from a list of 147 Experts worldwide ranked by ideXlab platform

Thierry Coupez - One of the best experts on this subject based on the ideXlab platform.

  • A Taylor discontinuous Galerkin method for the thermal solution in 3D Mold filling
    Computer Methods in Applied Mechanics and Engineering, 1999
    Co-Authors: Elisabeth Pichelin, Thierry Coupez
    Abstract:

    In continuity with the work of the authors, a Taylor discontinuous Galerkin method is introduced to solve the thermal problem in the context of the 3D Mold filling by viscous incompressible fluid. This numerical scheme is designed to deal with the physical phenomena of shear and temperature dependent viscosity, viscous heat generation and heat transfer by conduction and convection. A mixed temperature/heat flux formulation is introduced which enables to capture high temperature gradients without any polluting oscillations of the solution. The temperature and the heat flux are interpolated by a constant per element (P0 element) and an explicit solution based on the recursive time derivation of the equations is described. This approach aims to simulate non-isothermal flows of viscous fluid with moving free surfaces and more particularly the injection Molding process involving thermal shocks at the interface between the Cold Mold wall and the hot polymer. The extension of the method in the context of the Mold filling problem is given and several examples are proposed. The thermal solver is coupled to the mechanical solver which is based on a first order mixed finite element method for the kinematic and the solution of a transport equation for the flow front motion description. The proposed 3D technic is validated with known solutions and it is compared to 2D calculation obtained by different approaches. In continuity with the work of the authors, a Taylor discontinuous Galerkin method is introduced to solve the thermal problem in the context of the 3D Mold filling by viscous incompressible fluid. This numerical scheme is designed to deal with the physical phenomena of shear and temperature dependent viscosity, viscous heat generation and heat transfer by conduction and convection. A mixed temperature/heat flux formulation is introduced which enables to capture high temperature gradients without any polluting oscillations of the solution. The temperature and the heat flux are interpolated by a constant per element (P0 element) and an explicit solution based on the recursive time derivation of the equations is described. This approach aims to simulate non-isothermal flows of viscous fluid with moving free surfaces and more particularly the injection Molding process involving thermal shocks at the interface between the Cold Mold wall and the hot polymer. The extension of the method in the context of the Mold filling problem is given and several examples are proposed. The thermal solver is coupled to the mechanical solver which is based on a first order mixed finite element method for the kinematic and the solution of a transport equation for the flow front motion description. The proposed 3D technic is validated with known solutions and it is compared to 2D calculation obtained by different approaches.

  • a taylor discontinuous galerkin method for the thermal solution in 3d Mold filling
    Computer Methods in Applied Mechanics and Engineering, 1999
    Co-Authors: Elisabeth Pichelin, Thierry Coupez
    Abstract:

    Abstract In continuity with the work of the authors, a Taylor discontinuous Galerkin method is introduced to solve the thermal problem in the context of the 3D Mold filling by viscous incompressible fluid. This numerical scheme is designed to deal with the physical phenomena of shear and temperature dependent viscosity, viscous heat generation and heat transfer by conduction and convection. A mixed temperature/heat flux formulation is introduced which enables to capture high temperature gradients without any polluting oscillations of the solution. The temperature and the heat flux are interpolated by a constant per element (P0 element) and an explicit solution based on the recursive time derivation of the equations is described. This approach aims to simulate non-isothermal flows of viscous fluid with moving free surfaces and more particularly the injection Molding process involving thermal shocks at the interface between the Cold Mold wall and the hot polymer. The extension of the method in the context of the Mold filling problem is given and several examples are proposed. The thermal solver is coupled to the mechanical solver which is based on a first order mixed finite element method for the kinematic and the solution of a transport equation for the flow front motion description. The proposed 3D technic is validated with known solutions and it is compared to 2D calculation obtained by different approaches.

Elisabeth Pichelin - One of the best experts on this subject based on the ideXlab platform.

  • A Taylor discontinuous Galerkin method for the thermal solution in 3D Mold filling
    Computer Methods in Applied Mechanics and Engineering, 1999
    Co-Authors: Elisabeth Pichelin, Thierry Coupez
    Abstract:

    In continuity with the work of the authors, a Taylor discontinuous Galerkin method is introduced to solve the thermal problem in the context of the 3D Mold filling by viscous incompressible fluid. This numerical scheme is designed to deal with the physical phenomena of shear and temperature dependent viscosity, viscous heat generation and heat transfer by conduction and convection. A mixed temperature/heat flux formulation is introduced which enables to capture high temperature gradients without any polluting oscillations of the solution. The temperature and the heat flux are interpolated by a constant per element (P0 element) and an explicit solution based on the recursive time derivation of the equations is described. This approach aims to simulate non-isothermal flows of viscous fluid with moving free surfaces and more particularly the injection Molding process involving thermal shocks at the interface between the Cold Mold wall and the hot polymer. The extension of the method in the context of the Mold filling problem is given and several examples are proposed. The thermal solver is coupled to the mechanical solver which is based on a first order mixed finite element method for the kinematic and the solution of a transport equation for the flow front motion description. The proposed 3D technic is validated with known solutions and it is compared to 2D calculation obtained by different approaches. In continuity with the work of the authors, a Taylor discontinuous Galerkin method is introduced to solve the thermal problem in the context of the 3D Mold filling by viscous incompressible fluid. This numerical scheme is designed to deal with the physical phenomena of shear and temperature dependent viscosity, viscous heat generation and heat transfer by conduction and convection. A mixed temperature/heat flux formulation is introduced which enables to capture high temperature gradients without any polluting oscillations of the solution. The temperature and the heat flux are interpolated by a constant per element (P0 element) and an explicit solution based on the recursive time derivation of the equations is described. This approach aims to simulate non-isothermal flows of viscous fluid with moving free surfaces and more particularly the injection Molding process involving thermal shocks at the interface between the Cold Mold wall and the hot polymer. The extension of the method in the context of the Mold filling problem is given and several examples are proposed. The thermal solver is coupled to the mechanical solver which is based on a first order mixed finite element method for the kinematic and the solution of a transport equation for the flow front motion description. The proposed 3D technic is validated with known solutions and it is compared to 2D calculation obtained by different approaches.

  • a taylor discontinuous galerkin method for the thermal solution in 3d Mold filling
    Computer Methods in Applied Mechanics and Engineering, 1999
    Co-Authors: Elisabeth Pichelin, Thierry Coupez
    Abstract:

    Abstract In continuity with the work of the authors, a Taylor discontinuous Galerkin method is introduced to solve the thermal problem in the context of the 3D Mold filling by viscous incompressible fluid. This numerical scheme is designed to deal with the physical phenomena of shear and temperature dependent viscosity, viscous heat generation and heat transfer by conduction and convection. A mixed temperature/heat flux formulation is introduced which enables to capture high temperature gradients without any polluting oscillations of the solution. The temperature and the heat flux are interpolated by a constant per element (P0 element) and an explicit solution based on the recursive time derivation of the equations is described. This approach aims to simulate non-isothermal flows of viscous fluid with moving free surfaces and more particularly the injection Molding process involving thermal shocks at the interface between the Cold Mold wall and the hot polymer. The extension of the method in the context of the Mold filling problem is given and several examples are proposed. The thermal solver is coupled to the mechanical solver which is based on a first order mixed finite element method for the kinematic and the solution of a transport equation for the flow front motion description. The proposed 3D technic is validated with known solutions and it is compared to 2D calculation obtained by different approaches.

B. Brulé - One of the best experts on this subject based on the ideXlab platform.

  • Study of the thermal properties of miscible blends between poly(ether ketone ketone) (PEKK) and polyimide
    European Polymer Journal, 2015
    Co-Authors: S. Dominguez, Christophe Derail, Frédéric Leonardi, J. Pascal, B. Brulé
    Abstract:

    This study deals with the enhancement of the thermal behavior of thermostable thermoplastic polymers dedicated to high performance composites. Semi-crystalline poly(ether ketone ketone) and amorphous poly(imide) have been blended at different ratios by using a high temperature co-rotative twin screw extruder and injected using an injection-Molding machine with a "Cold" Mold. Injected samples have been characterized by different techniques and we especially discuss how crystallinity affects the composition of the amorphous phase and consequently the variation of the glass transition temperature value according to the composition that we propose to model by a modified Gordon-Taylor law. © 2014 Elsevier Ltd.

  • Study of the thermal properties of miscible blends between poly(ether ketone ketone) (PEKK) and polyimide
    European Polymer Journal, 2014
    Co-Authors: S. Dominguez, Christophe Derail, Frédéric Leonardi, J. Pascal, B. Brulé
    Abstract:

    Abstract This study deals with the enhancement of the thermal behavior of thermostable thermoplastic polymers dedicated to high performance composites. Semi-crystalline poly(ether ketone ketone) and amorphous poly(imide) have been blended at different ratios by using a high temperature co-rotative twin screw extruder and injected using an injection-Molding machine with a “Cold” Mold. Injected samples have been characterized by different techniques and we especially discuss how crystallinity affects the composition of the amorphous phase and consequently the variation of the glass transition temperature value according to the composition that we propose to model by a modified Gordon–Taylor law.

Waldemar Karaszewski - One of the best experts on this subject based on the ideXlab platform.

  • Blowing Kinetics, Pressure Resistance, Thermal Stability, and Relaxation of the Amorphous Phase of the PET Container in the SBM Process with Hot and Cold Mold. Part II: Statistical Analysis and Interpretation of Tests.
    Polymers, 2020
    Co-Authors: Paweł Wawrzyniak, Waldemar Karaszewski
    Abstract:

    The technology of filling drinks without preservatives (such as fresh juices, iced tea drinks, and vitaminized drinks) is carried out using hot filling. Mainly due to the production costs and lower carbon footprint, polyethylene terephthalate (PET) bottles are increasingly used in this technology. In this paper, the main aim is to describe and interpret the results of statistical analysis of the influence of the temperature of the blow Mold in the SBM (stretch blow Molding) process and the method of hot filling on the macroscopic and microscopic bottle properties. The macroscopic bottle properties were defined by the thickness profile, pressure resistance, thermal stability, and the coefficients of blowing kinetics. In addition, the influence of the SBM process on the microscopic PET material properties (in the bottle) relative to the microscopic preform properties was analyzed. The microscopic properties were defined by the degree of crystallite, density, and relaxation of the amorphous phase of the PET material. For this purpose, response surface experiments were performed for the two analyzed factors, i.e., the temperature of the blow Mold and the method of hot filling. The sample size was investigated to determine the minimum number of repetitions (number of bottles in the measurement series) required to achieve acceptable measurement uncertainty. The research conducted shows that, despite fulfilling the postulate of acceptable measurement uncertainty, in terms of the power of ANOVA (analysis of variance) in DOE (design of experiment), the accepted number of bottles in the measurement series is too small. The tests of the bottle material density, material crystallite, and relaxation of amorphous phase relative to the preform material density, material crystallite, and relaxation of amorphous phase show that microcavity effects occur during the deformation of the PET material, and that these are associated with the orientation of the microstructure. The blow kinetics study shows that there is a gradient of flow of the bottle material over the thickness of the bottle wall during blowing, and it has been deduced that the air temperature between the blow Mold and the wall of the blown bottle has an impact on the kinetics of blowing the bottle.

  • Blowing Kinetics, Pressure Resistance, Thermal Stability, and Relaxation of the Amorphous Phase of the PET Container in the SBM Process with Hot and Cold Mold. Part I: Research Methodology and Results.
    Polymers, 2020
    Co-Authors: Paweł Wawrzyniak, Waldemar Karaszewski
    Abstract:

    The technology of filling drinks without preservatives (such as fresh juices, iced tea drinks, vitaminized drinks) is carried out using hot filling. Mainly due to the production costs and lower carbon footprint, polyethylene terephthalate bottles, commonly called PET, are increasingly used in this technology. In this paper, the main aim is to describe the statistical analysis methodology of the influence of the temperature of the blow Mold in the SBM process and the method of hot filling on the macroscopic and microscopic bottle properties. The macroscopic bottle properties were defined by the thickness profile, pressure resistance, thermal stability, and the coefficients of blowing kinetics. Moreover, the influence of the SBM (stretch blow moulding) process on the microscopic PET material properties (in the bottle) relative to the microscopic preform properties was analyzed. The microscopic properties were defined by the degree of crystallite, density, and relaxation of the amorphous phase of the PET material. For this purpose, response surface experiments were performed for the two analyzed factors (independent variables), i.e., the temperature of the blow Mold and the method of hot filling. The sample size was investigated to determine the minimum number of repetitions (number of bottles in the measurement series) required to achieve acceptable measurement uncertainty. The research conducted shows that despite fulfilling the postulate of acceptable measurement uncertainty, in terms of the power of ANOVA (analysis of variance) in DOE (design of experiment) the accepted number of bottles in the measurement series is too small. The tests of the bottle material density, material crystallite, and relaxation of amorphous phase relative to the preform material density, material crystallite, and relaxation of amorphous phase show that the microcavity effects occur during the deformation of the PET material, and that these are associated with the orientation of the microstructure. The blow kinetics study shows that there is a gradient of flow of the bottle material over the thickness of the bottle wall during blowing, and it has been deduced that the air temperature between the blow Mold and the wall of the blown bottle has an impact on the kinetics of blowing the bottle.

Farhad Najarian - One of the best experts on this subject based on the ideXlab platform.

  • Roundness Error in Deep Hole Drilling using Twist Drills and Cold Mold Steel 718
    Indian journal of science and technology, 2017
    Co-Authors: Anis Farhan Kamaruzaman, Azlan Mohd Zain, Noordin Mohd Yusof, Noorfa Haszlinna Mustaffa, Farhad Najarian
    Abstract:

    Applications: Deep hole drilling is one of the machining processes which currently has been applied in the manufacturing area. The sophistication in some area such as aerospace, automotive, wind energy and nuclear power encourage the application of deep hole drilling. Objectives: In this study the effect of machining parameters on the roundness error during the drilling multiple deep holes of steel alloy using HSS Co5 DH100 straight shank twist drills for deep hole drilling of Cold Mold steel 718 towards the value of roundness error was investigated. Method: Drilling tests were carried out using a CNC milling machine under three different levels of minimum quantity lubricant (20, 30, 40 ml/hour) by drilling three different levels of depth of holes (65, 70, 75 mm), three different levels of spindle speeds (700, 800, 900 rpm) and three different levels of feed rates (50, 60, 70 mm/min). Findings: It was observed that the minimum value of roundness error obtained when using DoE approach and regression model is when cutting speed (V) is 700 rpm, minimum quantity lubricant (l) is 40 ml/hr and feed rate (f) equals 50 mm/min, depth of hole (d) is 65 mm. ANOVA analysis also proves that the combination of machining parameters obtained is significantly to the roundness error value that results in the roundness error minimum value and F statistic also showed that the model is important at the significance level of 95%.

  • Roundness Error Study in Deep Hole Drilling of Cold Mold Steel 718
    Indian journal of science and technology, 2017
    Co-Authors: Azizah Mohamad, Azlan Mohd Zain, Nor Bahiah Ahmad, Noordin Mohd Yusof, Farhad Najarian
    Abstract:

    Objective: The objective of this study is to investigate the experimental results of roundness error of machined holes using deep hole drilling process. The machining parameters include feed rate (f), spindle speed (s), depth of hole (d) and Minimum Quantity Lubrication MQL, (m). The work piece and tool material used in this study are Cold Mold Steel 718 and High Speed Steel, HSS (5mm diameter) with twist drill bit respectively. After that, to evaluate the quality of holes the roundness error has been used as machining performance. Method: A systematic approached based on Design of Experiment (DoE) was executed using Full Factorial design with added center point. Finding: Analysis of variance (ANOVA) was applied to the results to check the significance of the model. From the ANOVA analysis indicate that the model is significant for a confidence level of 0.05 or 95%.