Field Validation of a Systematic Approach to Modeling of Glass Delivery Systems

Author(s):  
Christopher Q. Jian ◽  
Muralidharan ◽  
Abhijit Dutta

In the fiberglass production process, glass is produced from various batch ingredients in a glass furnace. The molten glass is then delivered, through a delivery system that is often called the front-end system, to the various downstream forming operations. Front-end systems consist of various covered channels and forehearths. One of the major tasks of a front-end system is to insure that the glass is conditioned to the stringent specifications required by the forming operations. Improperly designed and/or operated front-end delivery systems can cause a number of problems to the forming operations, ranging from poor conversion efficiency (resulting in waste generation) due to glass defects to shortened service life. In today’s business environment, improvement in productivity, reduction in energy consumption, and minimization or elimination of waste generation have become priorities in managing and optimizing manufacturing operations. CFD has become an increasingly important tool for glass manufacturers to guide and optimize such system designs and operations. The current front-end model is developed to simultaneously simulate the chemically reacting turbulent flows in the superstructure and the laminar glass flow with strong buoyancy effects. Radiation from the superstructure wall surfaces and burner flames and internal radiation within the glass is modeled with the discrete ordinates (DO) radiation model in FLUENT. The turbulent reacting flow in the combustion space is calculated to obtain the flame shapes and lengths to accurately determine the heat transfer rate to the molten glass. The laminar glass flow, which is strongly influenced by natural convection, is calculated with temperature dependent physical properties. Simulations of the two radically different flow regimes are coupled through the interface boundary conditions in terms of temperature and heat flux continuity. Significant efforts were made to validate this approach with field measurements. Vertical temperature profiles were obtained in the glass melt as well as the combustion space at several strategically selected locations. The measurements were performed using two 6-element thermocouples housed in a platinum sheath. This coupled approach is expected to provide an effective tool that can be used to guide field operations as well as future system designs.

2000 ◽  
Author(s):  
Christopher Q. Jian

Abstract In the fiberglass production process, glass is produced from various batch ingredients in a glass furnace. The molten glass is then delivered, through a delivery system that is often called the front-end system, to the various downstream forming operations. Multiple complex processes take place in the glass furnace, which include the turbulent reacting flow in the combustion space; laminar flow dominated by natural convection in the molten glass; fusion of raw batch materials to form molten glass; radiation and convective heat transfer between the combustion space and the molten glass; bubbling flows in the glass; and Joule heating within the molten glass, etc. The main task of the glass furnace is to convert raw batch materials into glass and thermally and chemically condition the glass before being delivered to the front-end system. One of the major tasks of a front-end system is to insure that the glass is conditioned to the specifications required by the forming operations while maintaining the highest glass quality. Improperly designed and/or operated furnace and front end delivery system can cause a number of problems to the forming operations, ranging from poor glass quality with defects to shortened furnace service life. CFD has become an increasingly important tool for glass manufacturers to guide and optimize such system designs and operations. The current work is part of an effort to leverage CFD resources in the decision-making processes in engineering, operations, and businesses. The furnace modeling was performed using the recently implemented batch melting model jointly developed by Owens Corning and Fluent, Inc., which features three-dimensional simulation of an entire glass furnace including combustion, bubbling, and electrical boosting. The thermal coupling procedure between the combustion space, batch, and the melting tank along with the associated convergence issues are discussed. The modeling results are presented along with comparison with field measurements.


2015 ◽  
Vol 72 (4) ◽  
Author(s):  
Norwazan A. R. ◽  
Mohammad Nazri Mohd. Jaafar

The numerical simulations of swirling turbulent flows in isothermal condition in combustion chamber of burner were investigated. The aim is to characterize the main flow structures and turbulence in a combustor that is relevant to gas turbines. Isothermal flows with different inlet flow velocities were considered to demonstrate the effect of radial velocity. The inlet velocity, Uo is varied from 30 m/s to 60 m/s represent a high Reynolds number up to 3.00 X 105. The swirler was located at the upstream of combustor with the swirl number of 0.895. A numerical study of non-reacting flow in the burner region was performed using ANSYS Fluent. The Reynolds–Averaged Navier–Stokes (RANS) approach method was applied with the standard k-ɛ turbulence equations. The various velocity profiles were different after undergoing the different inlet velocity up to the burner exit. The results of velocity profile showed that the high U0 give better swirling flow patterns.


2015 ◽  
Vol 789-790 ◽  
pp. 477-483
Author(s):  
A.R. Norwazan ◽  
M.N. Mohd Jaafar

This paper is presents numerical simulation of isothermal swirling turbulent flows in a combustion chamber of an unconfined burner. Isothermal flows of with three different swirl numbers, SN of axial swirler are considered to demonstrate the effect of flow axial velocity and tangential velocity to define the center recirculation zone. The swirler is used in the burner that significantly influences the flow pattern inside the combustion chamber. The inlet velocity, U0 is 30 m/s entering into the burner through the axial swirler that represents a high Reynolds number, Re to evaluate the differences of SN. The significance of center recirculation zone investigation affected by differences Re also has been carried out in order to define a good mixing of air and fuel. A numerical study of non-reacting flow into the burner region is performed using ANSYS Fluent. The Reynolds–Averaged Navier–Stokes (RANS) realizable k-ε turbulence approach method was applied with the eddy dissipation model. An attention is focused in the flow field behind the axial swirler downstream that determined by transverse flow field at different radial distance. The results of axial and tangential velocity were normalized with the U0. The velocity profiles’ behaviour are obviously changes after existing the swirler up to x/D = 0.3 plane. However, their flow patterns are similar for all SN after x/D = 0.3 plane towards the outlet of a burner.


Author(s):  
Jayakrishnan Sindhu ◽  
Kunhee Choi ◽  
Sarel Lavy ◽  
Zofia K. Rybkowski ◽  
Ben F. Bigelow ◽  
...  

2018 ◽  
Vol 20 (4(69)) ◽  
pp. 78-90
Author(s):  
O.O. KARPENKO ◽  
L. A. TURENKO ◽  
H. U. KARPENKO

Topicality. The dominance in the national economy of resource-intensive multifield technologies and the lack of a sound public policy governing the formation, accumulation, storage, recycling, disposal and disposal of waste has led to a critical situation characterized by the further development of environmental threats. The slow pace of adoption and implementation of legal norms regarding the introduction of innovative technologies by types of economic activity, the inefficient use of the nature of resource potential and the unpreparedness of the business environment to intensify the introduction of the innovative model of the "green" economy lead to deepening the ecological crisis and aggravation of the socio-economic situation in society. After all, the high level of waste generation and low rates of their use as secondary raw materials have led to the fact that in Ukraine, in the industrial and municipal sector, significant volumes of solid waste accumulate each year, of which only a small part is used as secondary material resources, the rest fall into landfills. This fact determines the need for reform and development, taking into account global experience of the entire legal and economic system that regulates the use of natural resources, since the difference in the situation in Ukraine, as compared with other developed countries, lies in large volumes of waste generation and lack of infrastructure for handling them. . The "green" economy is an inalienable and effective tool for activities in all areas of life, namely in the areas of transport, agriculture, waste management and energy. This is not only an opportunity but a compulsory development path for all countries and states, including the EU member states..Aim and tasks. The purpose of the article is to determine the instrumental principles of regulation and to ensure the economic development of the process of environmentalization of the national model of the "green" economy. In order to achieve this goal, the study of the genesis of theoretical concepts concerning the ecologization of the development of the national model of the green economy, the determination of normative and legal instruments for enhancing the establishment of the principles of cleaner production and the substantiation of the scientific provisions regarding the development of the organizational and economic scenario for the development of the national green economy model are presented.Research results. The institutional principles of ecologization of the development of the national model of the "green" economy are considered. It is determined that further economic growth depends on the formation of an effective innovation policy of the state, based on the latest scientific and technological achievements and the transfer of environmentally sound technologies; ensuring the transfer of scientific research into resource-saving, knowledge-intensive, small and non-waste technologies, competitive goods and services, and activating processes for the formation of an ecologically oriented business environment in accordance with the global challenges of world development. It is substantiated that at the present stage it is important to ensure maximum full realization of the economic potential of regions in the strategy of formation of high-performance ecological-economic system, which is possible only at the expense of the implementation of the course of the "green" economy. The directions and priorities of development of secondary resource use are determined, taking into account both modern real possibilities and long-term economic, social and environmental interests of society; wide introduction of public-private partnership, cooperation and cooperation in central and local executive authorities, local self-government bodies; scientific, technological and methodical provision of waste management on an innovative basis; a significant increase in the role of regions and civil society in the reform of waste management; provision of financing and implementation of certain measures to further improve the management of waste management on a traditional basis. Three groups of tools have been formulated to promote resource-efficient low carbon economic development, as well as to monitor the transition process: imperative, economic and dispositive tools.Conclusions. It is substantiated that the institutional mechanisms of institutionalization of the process of environmentalization of the Ukrainian national green economy model can be considered: the dynamics of institutional and legislative and regulatory reforms in Ukraine regarding the implementation of the green economy model in the state policy mechanism, the development of state and regional governance institutions, the transformation of social relations and modification of administrative management with saturation of its ecological dominant and development of measures for priority determination their segments of environmentalization of national development. It is determined that the concept of the development of the "green" economy should determine the economic component that cements the growth of economic potential in the sectoral section of the state, the social component that serves as the basis for improving the life support system of Ukraine and the ecological component that forms the basis for implementing an environmentally sound policy of the state. The said confirms the urgency and importance of the institutional provision to enhance the process of environmentalization of the Ukrainian national green economy model, which should include the main legislative regulations of the state environmental policy and the international tendencies of ecologization of social development on the basis of the "green" economy.


2014 ◽  
Vol 69 (6) ◽  
Author(s):  
Norwazan A. R ◽  
Mohammad Nazri Mohd. Jaafar

This paper presents a numerical simulation of swirling turbulent flows in combustion chamber of unconfined burner. Isothermal flows with three different swirl numbers using axial swirler are used to demonstrate the effect of flow in axial velocity and tangential velocity on the center recirculation zone. The significance of center recirculation zone is to ensure a good mixing of air and fuel in order to get a better combustion. The inlet velocity, U0 is 30 m/s entering into the burner through the axial swirler that is represents a high Reynolds number. A numerical study of non-reacting flow in the burner region is performed using ANSYS Fluent. The Reynolds–Averaged Navier–Stokes (RANS) standard k-ε turbulence approach method was applied with the eddy dissipation model. The paper focuses the flow field behind the axial swirler downstream that determined by transverse flow field at different on radial distances. The results of axial and tangential velocity were normalized with the inlet velocity. The velocity profiles are different after undergoing the different swirler up to the burner exit. However, the results of velocity profile showed that the high SN gives a better swirling flow patterns. 


2020 ◽  
Vol 10 (4) ◽  
pp. 88
Author(s):  
Berit Sandberg

In a highly competitive business environment, integrating artists into corporate research and development (R&D) seems to be a promising way to foster inventiveness and idea generation. Given the importance of individual level innovation for product development, this study explores the benefits that employees experience from the artist-in-residence-program at Robert Bosch GmbH, Germany. Qualitative content analysis of interviews with scientists and engineers was performed in order to explore the impact of their encounters with artists in the theoretical framework of the triadic concept and transmission model of inspiration. The findings corroborate the notion that inspiration is a suitable theoretical underpinning for individual benefits of art–science collaborations in the front end of innovation. Scientists and engineers are inspired by the artists’ otherness and transcend their usual modes of perception in favor of enhanced focal, peripheral and bifocal vision. Whereas shifts in perspective are reflected in individual thinking patterns, researchers are hardly motivated to change their work-related behavior. The exchange with artists does not have a concrete impact on technological innovation, because researchers neither integrate impulses into their experiential world nor link them to fields of activity. In the case under scrutiny, artistic impulses do not contribute to idea generation in the sense of front-end activities. The study contributes to research on artists in businesses by illuminating the R&D environment as a hitherto neglected field of activity. While substantiating previous research on artist-in-science-residencies, the results suggest that the potential of such interdisciplinary endeavors is limited.


Author(s):  
Masoud Darbandi ◽  
Mohammad Bagher Barezban ◽  
Gerry E. Schneider

In this paper, the turbulent reacting flow in an industrial furnace is numerically simulated using the RANS equations. The two-equation standard k-ε and the eddy dissipation models are used respectively to close the turbulent closure problem and to consider the turbulence-chemistry interaction. The radiation transfer equation is solved using the discrete ordinates method (DOM). To calculate the radiation absorption coefficient in participating combustion gases, we use the spectral line-based weighted sum of grey gases (SLW) model and compare the achieved results with famous gray-based model, i.e., the weighted-sum-of-gray-gases (WSGG) model. The results of this research show that using the SLW model, the predicted heat transfer from the flame to the furnace walls is reduced due to the thermal radiation. So, the predicted temperature filed increases up to 5% near the outlet of furnace in comparison with the results of WSGG model, which is in more agreement with the experimental data. These results indicate that if one wishes to accurately predict the temperature field and the temperature sensitive quantities such as the NOx emission, one should use the spectral-based models to calculate the radiation absorption coefficient. The details are discussed in the results section.


A numerical technique is presented for the analysis of turbulent flow associated with combustion. The technique uses Chorin’s random vortex method (r.v.m .), an algorithm capable of tracing the action of elementary turbulent eddies and their cumulative effects without imposing any restriction upon their motion. In the past, the r.v.m . has been used with success to treat non-reacting turbulent flows, revealing in particular the mechanics of large-scale flow patterns, the so-called coherent structures. Introduced here is a flame propagation algorithm , also developed by Chorin, in conjunction with volume sources modelling the mechanical effects of the exothermic process of combustion. As an illustration of its use, the technique is applied to flow in a combustion tunnel w here the flame is stabilized by a back-facing step. Solutions for both non-reacting and reacting flow fields are obtained. Although these solutions are restricted by a set of far-reaching idealizations, they nonetheless mimic quite satisfactorily the essential features of turbulent combustion in a lean propane—air mixture that were observed in the laboratory by means of high speed schlieren photography.


2015 ◽  
Vol 18 (3) ◽  
pp. 558-576
Author(s):  
Robert Prosser

AbstractThere exist many spatial discretization schemes that are well able to provide accurate and stable approximations for isothermal turbulent flows. Comparatively little analysis has been made of the performance of these schemes in the presence of temperature gradients driven by combustion. In this paper, the effects of temperature gradients on numerical stability are explored. A surprising result is that temperature gradients in the flow have a tendency to impinge on left half plane (LHP) stability of the spatial discretization scheme. Reasons for this tendency are explored and two remedies are proposed: one based on the particular class of finite difference schemes, and one based on an alternative method of boundary condition specification.


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