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Author: search.filters.author.Ritthong, WiroteStart date: 2025

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Now showing 1 - 4 of 4
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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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    Energy-Efficient Paddy Rice Dehumidification using a Thermosyphon System
    (2025-07-01)
    Poungthong, Pongthep
    ;
    Promprasansuk, Sookjai
    ;
    Tanaratchat, Vikorn
    ;
    Promchai, Anuruk
    ;
    Ritthong, Wirote
    Efficient post-harvest drying is vital to maintain paddy rice quality, prevent spoilage, and extend storage life. This study presents a thermosyphon-based dehumidification system, tested with hot air and hot water heating at 60, 70, and 80 °C. The system includes a cylindrical drying chamber with automated controls for higher efficiency. Performance was evaluated using drying time, energy efficiency, and specific energy consumption (SEC). Results showed the system reduced paddy rice moisture from 26.65% to the target 14% (d.b.). Drying times with hot air were 128, 76, and 50 hours, while hot water required 104, 62, and 42 hours at 60, 70, and 80 °C, respectively. Hot water at 80°C achieved the fastest drying, completing the process in 42 hours. Energy performance analysis revealed the lowest SEC of 89.05 kWh/kg water for hot water at 80 °C, whereas hot air at 60 °C recorded the highest SEC of 1,204 kWh/kgwate. Overall, the thermosyphon system demonstrated strong potential for balancing drying speed and energy use. The study supports thermosyphon-based drying as a scalable, energy-efficient solution for post-harvest rice management, with hot water offering both rapid drying and efficiency
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    Optimization of Degradable Polylactic Acid-Based Coating Materials for Sustainable Wire Manufacturing Injection Process Using Computational Fluid Dynamics Analysis
    (2025-06-01)
    Nabudda, Kriengkrai
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    Promjariyakoon, Rattanaporn
    ;
    Kitprathaung, Nustha
    ;
    Ritthong, Wirote
    ;
    Intasonti, Sontinan
    This study investigates the impact of injection angle on polylactic acid (PLA) wire coating performance, focusing on flow dynamics, heat transfer, mass density, and pressure distribution. Three angles: 30°, 45°, and 60° were assessed for their effects on coating characteristics. At 30°, the flow is smooth with minimal turbulence, ensuring consistent deposition. The 60° angle increases velocity and material penetration but risks turbulence and uneven coating. The 45° angle optimally balances material mixing and flow stability. In terms of heat transfer, the 30° angle concentrates heat near the injection point, creating a steep thermal gradient, while the 60° angle disperses heat more broadly but with lower intensity. The 45° angle ensures uniform heat distribution, improving energy efficiency. Regarding mass density, the 30° angle favours localized deposition, ideal for concentrated applications, while the 60° angle promotes broader distribution with reduced concentration. The 45° angle optimises density uniformity and maintains structural integrity. Pressure distribution follows similar trends, with 30° and 60° angles causing uneven deposition, whereas the 45° angle ensures balanced pressure distribution. In conclusion, the 45° angle offers superior performance across all parameters, providing an optimal balance of efficiency, uniformity, and structural integrity, thus enhancing PLA wire coating quality for sustainable engineering applications.
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    Optimal Design of Cooling Rooms for Mackerel Using Computational Fluid Dynamics
    (2025-06-01)
    Nabudda, Kriengkrai
    ;
    Suntivarakorn, Ratchaphon
    ;
    Artnaseaw, Apichart
    ;
    Ritthong, Wirote
    ;
    Poungthong, Pongthep
    This study utilises computational fluid dynamics (CFD) simulations to investigate airflow and temperature distributions in cold storage environments equipped with various fan and duct configurations. It assesses the effectiveness of single and dual evaporator fans (mounted at both front and rear) and front-and rear-positioned air ducts in enhancing air circulation and thermal uniformity. Results indicate that single rear-mounted fans promote localised airflow but lead to thermal stratification and stagnant zones, while front-mounted fans struggle to circulate air effectively towards the rear. Rear-positioned ducts improve air distribution but require further optimisation to address residual stratification. Dual rear-mounted evaporator fans deliver the most consistent cooling, minimising temperature variation and reducing compressor load, thus improving energy efficiency. Although dual front-mounted fans enhance circulation, they still exhibit thermal inconsistencies. The study also underscores the importance of measuring fan outlet velocity to ensure stable environmental conditions. Overall, the findings emphasise the necessity of optimised airflow strategies, appropriate fan placement, and ongoing system monitoring to achieve uniform cooling and preserve the quality of temperature-sensitive products in cold storage applications.