J. Banaszek - Academia.edu (original) (raw)
Papers by J. Banaszek
Numerical Heat Transfer, Part B: Fundamentals, 1990
The paper presents the potential of an efficient front tracking technique on a fixed control-volu... more The paper presents the potential of an efficient front tracking technique on a fixed control-volume grid in micro-macroscopic numerical modeling of both binary alloy solidification and a solid-liquid phase transition of single-component optically functioning materials. In the former case, the method, basing on the assumption that an envelope of columnar dendrite tips moves locally according to a single crystal growth law, allows more precise identification of zones of different dendritic structures developing within the two-phase region, and thus more detailed analysis of some closing models. It is shown, by exploiting the commonly used benchmark problem that a porous medium model of the columnar mush must be carefully chosen since it strongly affects the predicted macro-segregation pattern. In the case of solidification of a single-component semi-transparent material the combination of the front tracking method with the immersed boundary technique provides a new simulation model, w...
International Journal of Numerical Methods for Heat & Fluid Flow, 2014
ABSTRACT Purpose ‐ The purpose of this paper is to endorse the idea of using a special post-calcu... more ABSTRACT Purpose ‐ The purpose of this paper is to endorse the idea of using a special post-calculating front tracking (FT) procedure, along with the enthalpy-porosity front tracking (EP-FT) single continuum model, in order to identify zones of different dendritic microstructures developing in the mushy zone during cooling and solidification of a binary alloy. Design/methodology/approach ‐ The 2D and 3D algorithms of the FT approach along with different crystal growth laws were implemented in macroscopic calculations of binary alloy solidification with the identification of different dendrite zones developing during the process. Findings ‐ Direct comparison of results predicted by the FT model with that based on the concept of the critical value of the solid volume fraction shows the sensitivity of the latter on an arbitrary assumed value of the dendrite coherency point (DCP). Moreover, for a carefully chosen DCP value the second model provides results that are close to those given by the FT-based approach. It is also observed that the macro-segregation pattern obtained by the proposed method is hardly influenced by chosen dendrite tip kinetics. Originality/value ‐ To the best authors' knowledge, for the first time the 3D FT model has been used along with the enthalpy porosity approach to simulate the development of zones of different dendrite morphology during binary alloy solidification. And, a weak influence of assumed different dendrite tip kinetics on the macro-segregation pattern has been proved, what justifies this underlying assumption of the EP-FT method.
ABSTRACT Numerical simulation of binary alloy solidification process is a challenging task due to... more ABSTRACT Numerical simulation of binary alloy solidification process is a challenging task due to coexistence of phenomena related to various temporal/spatial scales and coexistence of zones, i.e. columnar and equiaxed dendrites, where various fluid flow models should be applied. Presented paper is devoted to exploration of the recently developed numerical model of solidification based on the front tracking approach. The influence of the columnar dendrites region porosity on the macrosegregation formation is investigated. Presented results stay in qualitative agreement with the reference data but expose some additional details absent in the results of simulation performed with the simpler model.
Archives of Thermodynamics, 2014
ABSTRACT Heat flow in heterogeneous media with complex microstructure follows tortuous path and t... more ABSTRACT Heat flow in heterogeneous media with complex microstructure follows tortuous path and therefore determination of temperature distribution in them is a challenging task. Two-scales, micro-macro model of heat conduction with phase change in such media was considered in the paper. A relation between temperature distribution on the microscopic level, i.e., on the level of details of microstructure, and the temperature distribution on the macroscopic level, i.e., on the level where the properties were homogenized and treated as effective, was derived. The expansion applied to this relation allowed to obtain its more simplified, approximate form corresponding to separation of micro- and macro-scales. Then the validity of this model was checked by performing calculations for 2D microstructure of a composite made of two constituents. The range of application of the proposed micro-macro model was considered in transient states of heat conduction both for the case when the phase change in the material is present and when it is absent. Variation of the effective thermal conductivity with time was considered and a criterion was found for which application of the considered model is justified.
International Journal of Numerical Methods for Heat & Fluid Flow, 2008
Purpose – This paper aims to tackle the problem of some ambiguity of the momentum equation formul... more Purpose – This paper aims to tackle the problem of some ambiguity of the momentum equation formulation in the commonly used macroscopic models of two-phase solid/liquid region, developing during alloy solidification. These different appearances of the momentum equation are compared and the issue is addressed of how the choice of the particular form affects velocity and temperature fields. Design/methodology/approach –
Advances in Computational Heat Transfer. Proceedings of the International Symposium, 1997
Page 128. NUMERICAL ANALYSIS OF RADIATIVE HEAT FLUX ON WALLS OF THE COMBUSTION CHAMBER IN A DIESE... more Page 128. NUMERICAL ANALYSIS OF RADIATIVE HEAT FLUX ON WALLS OF THE COMBUSTION CHAMBER IN A DIESEL ENGINE Jerzy Banaszek, Piotr Furmanski, Tomasz S. Wisniewski Institute of Heat Engineering, Warsaw University of Technology, ul. ...
ABSTRACT A novel front tracking technique on a fixed Cartesian grid, based on the kinetics of den... more ABSTRACT A novel front tracking technique on a fixed Cartesian grid, based on the kinetics of dendritic growth, is discussed. It is used to predict the influence of both alloy composition and convective heat transfer coefficient on the size of the undercooled liquid zone in front of columnar dendrite tips during solidification of Al-Cu alloys driven by conduction in a square mould. The model is compared with the enthalpy approach showing its superiority in the detection of the undercooled zone and, thus, in potentially modelling of columnar/equiaxed grain structures. The effect of natural thermal convection on the shape of the mushy zone is demonstrated by use of the enthalpy-porous medium model, and an approach to incorporating convection into the non-equilibrium front-tracking model is outlined.
Encyclopedia of Thermal Stresses, 2014
ABSTRACT OverviewThermally driven solid-liquid phase change is an underlying phenomenon in numero... more ABSTRACT OverviewThermally driven solid-liquid phase change is an underlying phenomenon in numerous technologies occurring in cryosurgery and cryogenic preservation systems, heating and AC systems, manufacturing technologies, and others. Multi-scale and multiphase transport processes accompanying melting and solidification of a single- and multicomponent media must be precisely controlled to get a high quality final product, free from undesired compositional and internal stresses non-homogeneities, cracks, voids, and the resulting weak mechanical properties. To effectively control and optimize these technologies, there is a need for better understanding a very complex physics and for detailed information of temporal pressure, velocity, temperature, and species concentration fields, developing with the progressing phase change process. Therefore, the main purpose of this entry is to familiarize a reader with both involved physics of the solid-liquid phase change and essentials of mathema ...
Advances in Computational Heat Transfer. Proceedings of the International Symposium, 1997
Page 474. FIXED GRID FINITE ELEMENT ANALYSIS OF SOLIDIFICATION Jerzy Banaszek*, Marek Rebow* and ... more Page 474. FIXED GRID FINITE ELEMENT ANALYSIS OF SOLIDIFICATION Jerzy Banaszek*, Marek Rebow* and Tomasz A. Kowalewski** * Institute of Heat Engineering, Warsaw University of Technology, PL 00-665 Warsaw ...
Materials Science Forum, 2006
Materials Science Forum, 2006
Aircraft Engineering and Aerospace Technology, 2014
ABSTRACT Purpose - The purpose of this study is to developed a simplified thermo-fluid model of a... more ABSTRACT Purpose - The purpose of this study is to developed a simplified thermo-fluid model of an engine cowling in a small airplane. An aircraft engine system is composed of different elements operating at various temperatures and in conjunction with the composite nacelle creates a region with high intensity of heat transfer to be covered by the cooling/ventilation systems. Therefore a thermal analysis, accounting for the complex heat transfer modes, is necessary in order to verify that an adequate cooling is ensured and that temperatures of the nacelle are maintained within the operating limits throughout the whole aircraft's flight. Design/methodology/approach - Simplified numerical simulations of conductive, convective and radiative heat transfer in the engine bay of the small airplane I-23 in a tractor arrangement were performed for different air inlet and outlet configurations and for varying conditions existing in air inlets during the flight. The model is based on the control volume approach for heat and fluid flow as well as for thermal radiation and on k-epsilon turbulence model. Findings - The flow and temperature distributions inside the cowling were determined, and high-temperature spots on the internal side of the nacelle and on other airplane systems located close to the turboprop engine and the exhaust system were found. The thermal radiation was found to play the key role in heat transfer inside the engine bay. The optimal configuration of air inlets and outlets was determined. Practical implications - The obtained results will help in future studies on ventilation and cooling systems and will contribute to the selection of materials for parts of the engine bay and the nacelle as well as in developing solutions for reducing the temperature inside the cowling of the airplane I-23. Originality/value - A complete simplified thermo-fluid model of heat transfer inside the engine bay of the airplane I-23 was developed. Additionally, influence of the thermal radiation on temperature distribution at the nacelle was investigated.
Progress in Computational Fluid Dynamics, An International Journal, 2005
ABSTRACT The paper presents two integral formulations of radiative heat transfer in emitting, abs... more ABSTRACT The paper presents two integral formulations of radiative heat transfer in emitting, absorbing and scattering media. These formulations are the basis for application of the boundary element method (BEM) and the finite element method (FEM) for a single mode or combined modes heat transfer problems where radiation plays a significant role. Examples of application of the method to analysis of radiative heat transfer in internal combustion engines and in thermal insulations are given.
Numerical Heat Transfer, Part A: Applications, 1999
Numerical Heat Transfer, Part B: Fundamentals, 1990
The paper presents the potential of an efficient front tracking technique on a fixed control-volu... more The paper presents the potential of an efficient front tracking technique on a fixed control-volume grid in micro-macroscopic numerical modeling of both binary alloy solidification and a solid-liquid phase transition of single-component optically functioning materials. In the former case, the method, basing on the assumption that an envelope of columnar dendrite tips moves locally according to a single crystal growth law, allows more precise identification of zones of different dendritic structures developing within the two-phase region, and thus more detailed analysis of some closing models. It is shown, by exploiting the commonly used benchmark problem that a porous medium model of the columnar mush must be carefully chosen since it strongly affects the predicted macro-segregation pattern. In the case of solidification of a single-component semi-transparent material the combination of the front tracking method with the immersed boundary technique provides a new simulation model, w...
International Journal of Numerical Methods for Heat & Fluid Flow, 2014
ABSTRACT Purpose ‐ The purpose of this paper is to endorse the idea of using a special post-calcu... more ABSTRACT Purpose ‐ The purpose of this paper is to endorse the idea of using a special post-calculating front tracking (FT) procedure, along with the enthalpy-porosity front tracking (EP-FT) single continuum model, in order to identify zones of different dendritic microstructures developing in the mushy zone during cooling and solidification of a binary alloy. Design/methodology/approach ‐ The 2D and 3D algorithms of the FT approach along with different crystal growth laws were implemented in macroscopic calculations of binary alloy solidification with the identification of different dendrite zones developing during the process. Findings ‐ Direct comparison of results predicted by the FT model with that based on the concept of the critical value of the solid volume fraction shows the sensitivity of the latter on an arbitrary assumed value of the dendrite coherency point (DCP). Moreover, for a carefully chosen DCP value the second model provides results that are close to those given by the FT-based approach. It is also observed that the macro-segregation pattern obtained by the proposed method is hardly influenced by chosen dendrite tip kinetics. Originality/value ‐ To the best authors' knowledge, for the first time the 3D FT model has been used along with the enthalpy porosity approach to simulate the development of zones of different dendrite morphology during binary alloy solidification. And, a weak influence of assumed different dendrite tip kinetics on the macro-segregation pattern has been proved, what justifies this underlying assumption of the EP-FT method.
ABSTRACT Numerical simulation of binary alloy solidification process is a challenging task due to... more ABSTRACT Numerical simulation of binary alloy solidification process is a challenging task due to coexistence of phenomena related to various temporal/spatial scales and coexistence of zones, i.e. columnar and equiaxed dendrites, where various fluid flow models should be applied. Presented paper is devoted to exploration of the recently developed numerical model of solidification based on the front tracking approach. The influence of the columnar dendrites region porosity on the macrosegregation formation is investigated. Presented results stay in qualitative agreement with the reference data but expose some additional details absent in the results of simulation performed with the simpler model.
Archives of Thermodynamics, 2014
ABSTRACT Heat flow in heterogeneous media with complex microstructure follows tortuous path and t... more ABSTRACT Heat flow in heterogeneous media with complex microstructure follows tortuous path and therefore determination of temperature distribution in them is a challenging task. Two-scales, micro-macro model of heat conduction with phase change in such media was considered in the paper. A relation between temperature distribution on the microscopic level, i.e., on the level of details of microstructure, and the temperature distribution on the macroscopic level, i.e., on the level where the properties were homogenized and treated as effective, was derived. The expansion applied to this relation allowed to obtain its more simplified, approximate form corresponding to separation of micro- and macro-scales. Then the validity of this model was checked by performing calculations for 2D microstructure of a composite made of two constituents. The range of application of the proposed micro-macro model was considered in transient states of heat conduction both for the case when the phase change in the material is present and when it is absent. Variation of the effective thermal conductivity with time was considered and a criterion was found for which application of the considered model is justified.
International Journal of Numerical Methods for Heat & Fluid Flow, 2008
Purpose – This paper aims to tackle the problem of some ambiguity of the momentum equation formul... more Purpose – This paper aims to tackle the problem of some ambiguity of the momentum equation formulation in the commonly used macroscopic models of two-phase solid/liquid region, developing during alloy solidification. These different appearances of the momentum equation are compared and the issue is addressed of how the choice of the particular form affects velocity and temperature fields. Design/methodology/approach –
Advances in Computational Heat Transfer. Proceedings of the International Symposium, 1997
Page 128. NUMERICAL ANALYSIS OF RADIATIVE HEAT FLUX ON WALLS OF THE COMBUSTION CHAMBER IN A DIESE... more Page 128. NUMERICAL ANALYSIS OF RADIATIVE HEAT FLUX ON WALLS OF THE COMBUSTION CHAMBER IN A DIESEL ENGINE Jerzy Banaszek, Piotr Furmanski, Tomasz S. Wisniewski Institute of Heat Engineering, Warsaw University of Technology, ul. ...
ABSTRACT A novel front tracking technique on a fixed Cartesian grid, based on the kinetics of den... more ABSTRACT A novel front tracking technique on a fixed Cartesian grid, based on the kinetics of dendritic growth, is discussed. It is used to predict the influence of both alloy composition and convective heat transfer coefficient on the size of the undercooled liquid zone in front of columnar dendrite tips during solidification of Al-Cu alloys driven by conduction in a square mould. The model is compared with the enthalpy approach showing its superiority in the detection of the undercooled zone and, thus, in potentially modelling of columnar/equiaxed grain structures. The effect of natural thermal convection on the shape of the mushy zone is demonstrated by use of the enthalpy-porous medium model, and an approach to incorporating convection into the non-equilibrium front-tracking model is outlined.
Encyclopedia of Thermal Stresses, 2014
ABSTRACT OverviewThermally driven solid-liquid phase change is an underlying phenomenon in numero... more ABSTRACT OverviewThermally driven solid-liquid phase change is an underlying phenomenon in numerous technologies occurring in cryosurgery and cryogenic preservation systems, heating and AC systems, manufacturing technologies, and others. Multi-scale and multiphase transport processes accompanying melting and solidification of a single- and multicomponent media must be precisely controlled to get a high quality final product, free from undesired compositional and internal stresses non-homogeneities, cracks, voids, and the resulting weak mechanical properties. To effectively control and optimize these technologies, there is a need for better understanding a very complex physics and for detailed information of temporal pressure, velocity, temperature, and species concentration fields, developing with the progressing phase change process. Therefore, the main purpose of this entry is to familiarize a reader with both involved physics of the solid-liquid phase change and essentials of mathema ...
Advances in Computational Heat Transfer. Proceedings of the International Symposium, 1997
Page 474. FIXED GRID FINITE ELEMENT ANALYSIS OF SOLIDIFICATION Jerzy Banaszek*, Marek Rebow* and ... more Page 474. FIXED GRID FINITE ELEMENT ANALYSIS OF SOLIDIFICATION Jerzy Banaszek*, Marek Rebow* and Tomasz A. Kowalewski** * Institute of Heat Engineering, Warsaw University of Technology, PL 00-665 Warsaw ...
Materials Science Forum, 2006
Materials Science Forum, 2006
Aircraft Engineering and Aerospace Technology, 2014
ABSTRACT Purpose - The purpose of this study is to developed a simplified thermo-fluid model of a... more ABSTRACT Purpose - The purpose of this study is to developed a simplified thermo-fluid model of an engine cowling in a small airplane. An aircraft engine system is composed of different elements operating at various temperatures and in conjunction with the composite nacelle creates a region with high intensity of heat transfer to be covered by the cooling/ventilation systems. Therefore a thermal analysis, accounting for the complex heat transfer modes, is necessary in order to verify that an adequate cooling is ensured and that temperatures of the nacelle are maintained within the operating limits throughout the whole aircraft's flight. Design/methodology/approach - Simplified numerical simulations of conductive, convective and radiative heat transfer in the engine bay of the small airplane I-23 in a tractor arrangement were performed for different air inlet and outlet configurations and for varying conditions existing in air inlets during the flight. The model is based on the control volume approach for heat and fluid flow as well as for thermal radiation and on k-epsilon turbulence model. Findings - The flow and temperature distributions inside the cowling were determined, and high-temperature spots on the internal side of the nacelle and on other airplane systems located close to the turboprop engine and the exhaust system were found. The thermal radiation was found to play the key role in heat transfer inside the engine bay. The optimal configuration of air inlets and outlets was determined. Practical implications - The obtained results will help in future studies on ventilation and cooling systems and will contribute to the selection of materials for parts of the engine bay and the nacelle as well as in developing solutions for reducing the temperature inside the cowling of the airplane I-23. Originality/value - A complete simplified thermo-fluid model of heat transfer inside the engine bay of the airplane I-23 was developed. Additionally, influence of the thermal radiation on temperature distribution at the nacelle was investigated.
Progress in Computational Fluid Dynamics, An International Journal, 2005
ABSTRACT The paper presents two integral formulations of radiative heat transfer in emitting, abs... more ABSTRACT The paper presents two integral formulations of radiative heat transfer in emitting, absorbing and scattering media. These formulations are the basis for application of the boundary element method (BEM) and the finite element method (FEM) for a single mode or combined modes heat transfer problems where radiation plays a significant role. Examples of application of the method to analysis of radiative heat transfer in internal combustion engines and in thermal insulations are given.
Numerical Heat Transfer, Part A: Applications, 1999