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Physics-Guided CFD–ML Framework for Sustainable Classical Wire Coating with Power-Law Fluids
(2026-07-01)
Nabudda, Kriengkrai
;
Poungthong, Pongthep
;
Ritthong, Wirote
;
Elumalai, P. V.
This study presents an integrated Computational Fluid Dynamics (CFD) and machine learning framework for analyzing and optimizing classical wire coating processes involving non-Newtonian power-law fluids. A two-dimensional axisymmetric CFD model was developed in ANSYS Fluent 2024R1 to investigate the effects of the power-law index (n = 0.3–1.0) on flow, pressure, temperature, and density fields under non-isothermal conditions. A Latin Hypercube Sampling-based Design of Experiments was coupled with surrogate modelling and Sobol sensitivity analysis to evaluate process performance and identify optimal operating conditions. The results showed that velocity distributions were highly dependent on fluid rheology, with shear-thinning fluids producing broader plug-like flow regions and more uniform velocity profiles. In contrast, pressure, temperature, and density fields exhibited limited sensitivity to variations in the power-law index. Optimization indicated that low power-law indices, moderate pressure gradients, and low-to-moderate wire speeds maximize coating thickness while minimizing material loss. Ridge Polynomial Regression achieved excellent predictive accuracy for all response variables (R<sup>2</sup> > 0.995). Sensitivity analysis revealed that the initial die gap is the dominant factor governing coating thickness, whereas material loss is influenced by combined effects of die geometry, fluid rheology, and wire speed. The proposed framework provides an efficient tool for process optimization and material conservation in industrial wire coating applications.
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Evaluation and improvement of ventilation systemreduceinside low-costparticle contaminationautomation line to
(2020-02-28)
Puangburee, Lamai
;
Busayaporn, Wutthikrai
;
Kaewbumrung, Mongkol
;
Thongsri, Jatuporn
A Low-Cost Automation (LCA) line, a group of machines to manufacture hard disk drive’s components located inside a clean room of factory, faces the problem of particle contamination caused by an improper ventilation system. To solve this problem, Computational Fluid Dynamics (CFD) has been implemented to evaluate airflow and simulate solutions to improve the ventilation system of the LCA. By using actual operating conditions collected at the factory and Fluent CFD software, the simulation showed that airflow patterns in such areas were substandard. For example, the large areas of recirculation zone with air velocities lower than 0.2 m/s such as Fan Filter Units’ conveyor and Work Area. The low ve-locity of the airflow can cause particle contamination and leads to low-quality production. To reduce the particle contamination, we suggested novel solutions based on the CFD results by increasing the momen-tum source (S<inf>m</inf>) and/or redesigning the LCA’s model especially extending its height of cover. The increasing of S<inf>m</inf> can be simply implemented by increasing the air-condition power to the optimal values accord-ing to the calculation leading to a reduction in recir-culation areas. In addition, extending the height of the LCA’s cover also improved the air velocities in the critical areas to meet the factory’s standard.
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Extra-low Reynolds number vane separation using immersed boundary method
(2019-01-01)
Prapamonthon, Prasert
;
Yin, Bo
;
Yang, Guowei
Nowadays, mini unmanned aerial vehicles (MUAVs) and micro air vehicles (MAVs) are not only beneficially used as aviation models but also as modern drones for military missions and other civilian applications. Hence, research and development of propulsion sources for MUAVs and MAVs dynamically increase with a future trend of high performance, but low energy consumption. Certainly, using micro and ultra-small-size gas turbine is a good option for the propulsion source. To achieve ideal flight of MUAVs and MAVs powered by micro and ultra-small-size gas turbines under this trend, understanding of flow phenomena at wide ranges of Reynolds number is essential. This research presents a 2D numerical study of characteristics of laminar flow separation and the trailing-edge vortex on a turbine vane at extra-low Reynolds numbers (Res) i.e. Re = 1800 and 3600, and three rotational angles (a) i.e. a = 0º, 15º and 30º using immersed boundary method (IBM). With this method, the problem of incompressible flow is addressed by a sharp interface IBM. Numerical results indicate that IBM can characterize phenomena of laminar separation flow, which usually happens on the turbine airfoil when laminar boundary layer cannot overcome adverse pressure gradients and viscous effects. To our current knowledge, this may be the first research to study flow behavior at such low Res for gas turbine vanes using IBM. Even though it is now not common to operate micro and ultra-small-size gas turbines under these conditions, it is important to know how aerodynamic performance may be if micro and ultra-small-size gas turbines need to run under such conditions in the near future.
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A CFD investigation of airflow in a hard disk drive production line to detect the cause(s) of contamination and its mitigation
(2017-07-02)
Khaokom, Adisorn
;
Thongsri, Jatuporn
;
Kaewkhaw, Polsate
Contamination exceeds the standards in certain areas within the production line of hard disk drive (HDD) manufacturing, such as in the clean room of a factory. In order to find the cause(s) and solve the problem, we decided to use the computational fluid dynamics (CFD) to simulate the airflow within the production line. The results show the cause of contamination, which is from the exhaust fan installed in the electrical testing machine in the production line of HDD manufacturing, which releases large amounts of particles. To resolve this problem, the CFD results were analyzed to design and create a new cover for the exhaust fan. Once this invention is installed to the electrical testing machine, it can control the airflow to float into other areas that do not affect nor contaminate the product. The factory utilized this research. Other than solving contamination problems that exceed standards, it also saves production costs from purchasing new machines as well.
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Effect of central cone-shaped bluff body on performance of premixed LPG burner
(2017-03-05)
Laphirattanakul, Ponepen
;
Charoensuk, Jarruwat
Improvement of air entrainment rate for liquefied petroleum gas (LPG) premixed burner was achieved by placing a needle rod inside a circular fuel jet nozzle. To investigate the effect of needle rod on flow entrainment, selection of experimental results together with investigation on jet characteristics using CFD are presented. The predictive quality was achieved after performing grid refinement and validation of turbulent model against existing experimental results. Two modified standard k-ε turbulent models were employed for prediction of the jets. The results indicated that the annular port created narrower jet pattern with higher degree of penetration. The momentum decay rate was significantly lower with an average of 48% at z/D = 30, for instance, corresponding to lower Reynolds shearing stress associated with jet shape upstream. This corresponded to the vorticity magnitude of the inner core that caused transport of jet momentum into the central region of the jet near the exit plane. In contrast, the circular one performed more expanded pattern together with faster decay rate. This expanded jet created limitation of air entrainment when issuing into a confined duct, while deeper penetration of the annular jet created greater entrainment. An averaged improvement of air entrainment was found at 25% for the range of firing rate between 1.8 and 4.4 kW.

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