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    Effect of Detergent, Temperature, and Solution Flow Rate on Ultrasonic Cleaning: A Case Study in the Jewelry Manufacturing Process
    (2025-12-01)
    Juangjai, Natthakarn
    ;
    Chaiaiad, Chatchapat
    ;
    Thongsri, Jatuporn
    This research investigated how detergent type and concentration, solution temperature, and flow rate affect ultrasonic cleaning efficiency in jewelry manufacturing. A silver bracelet without gemstones served as the test sample, and the study combined harmonic response analysis to assess acoustic pressure distribution with computational fluid dynamics to examine fluid flow patterns inside an ultrasonic cleaning machine. Cleaning tests were performed under real factory conditions to verify the simulations. Results showed that cleaning efficiency depends on the combined chemical and ultrasonic effects. Adding detergent lowered surface tension, encouraging cavitation bubble formation; higher temperatures (up to 60 °C) softened dirt, making removal easier; and moderate solution flow improved the cleaning, helping to carry dirt away from jewelry surfaces. Too much flow, however, decreased cavitation activity. The highest cleaning efficiency (93.890%) was achieved with 3% U-type detergent at 60 °C and a flow rate of 5 L/min, while pure water at room temperature (30 °C) without flow had the lowest efficiency (0.815%), confirmed by weighing and scanning electron microscope measurements. Interestingly, maximum ultrasonic power concentration did not always match the highest cleaning efficiency. The study supports sustainable practices by limiting detergent use to 3%, in line with Sustainable Development Goal (SDG) 9 (Industry, Innovation, and Infrastructure).
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    A Modern Ultrasonic Cleaning Tank Developed for the Jewelry Manufacturing Process and Its Cleaning Efficiency
    (2025-10-01)
    Chaiaiad, Chatchapat
    ;
    Borthai, Pawantree
    ;
    Thongsri, Jatuporn
    This research details the development and evaluation of a Modern Ultrasonic Cleaning Tank (MUCT) designed to enhance cleaning efficiency in jewelry manufacturing, particularly for silver jewelry, replacing the traditional method, which was less efficient and had higher operating costs. The MUCT offers capabilities of single- or dual-frequency ultrasonic operation (28 kHz and 40 kHz) and adjustable transducer positioning. An advanced method involving computer simulations, utilizing harmonic response analysis and transient dynamic analysis, was employed to determine the acoustic pressure inside the MUCT, thereby indicating the cavitation intensity required to achieve high cleaning efficiency. Simulation results confirm that this design can distribute acoustic pressure throughout the MUCT, as intended. A prototype MUCT was assembled, and its operation was validated through foil corrosion tests, ultrasonic power concentration (UPC) measurements, and jewelry cleaning tests. The results revealed that the MUCT’s center provided the maximum UPC of 28 W/L and an acoustic pressure of 30.43 MPa, effectively operating at single and dual frequencies, and achieving superior dirt removal. The highest cleaning efficiency of 100% was achieved using dual frequency with a 97% water and 3% dishwashing liquid mixture at 60 °C, exceeding the 23.52% obtained with water at 27 °C without ultrasonic treatment. The MUCT, successfully integrated into the manufacturing process, offers customizable features to meet various cleaning needs, providing flexibility, improved performance, and cost savings.
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    Development of a Small Ultrasonic Cleaning Bath based on Harmonic Response Analysis
    (2024-01-01)
    Worradechaudom, Warakorn
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    Chaiaiad, Chatchapat
    ;
    Thongsri, Jatuporn
    This article reports the development of a 0.27 L small ultrasonic cleaning bath (SUCB) with a 45 kHz single transducer to enhance cleaning efficacy based on harmonic response analysis (HRA). First, the HRA results revealed the uneven acoustic pressure inside the SUCB emerged from the transducer, depending on the applied voltage. As expected, the higher the applied voltage, the greater the acoustic pressure, and away from the transducer, the acoustic pressure decreased, consistent with the foil corrosion test, confirming the research methodology's credibility. Then, the transducer has been redesigned to develop the SUCB. Last, using the HRA, the simulation results indicated that the redesigned transduce, adding front and back masses like a horn shape, enhanced the acoustic pressure and helped to increase cleaning efficacy compared to the conventional SUCB. The findings were applied to develop a new generation of the SUCB. This article presents a step-by-step HRA technique that can be practically used in manufacturing design.
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    Transient Thermal-Electric Analysis of Peltier Cooling Plate for Developing a Mini Refrigerator
    (2024-01-01)
    Chaiaiad, Chatchapat
    ;
    Thongsri, Jatuporn
    This article reports a transient thermal-electric analysis (TEA), a simulation of a Peltier cooling plate (PCP) aimed to develop into a mini refrigerator soon. This conventional PCP includes 110 Peltier cells, which are a series of connecting cells, and two sandwiched ceramic plates. First, the experiment measured the PCP's applied current (I) and temperature (T) under the desired conditions. Then, the TEA was employed to determine the I and T of the PCP, which were compared with the experimental results. As expected, the comparison shows the consistency between the simulation and experimental results, validating the credibility of the methodology and simulation results. The simulation results revealed that the temperature difference (Δ T) between the two sandwiched ceramic plates increased with the increase of I and the number of cells, as expected. Last, the proposed model of PCP, I of 500 mA, 126 Peltier cells, and reducing the gap between cells, could generate T of -2.3761C on the cool ceramic plate lower than the conventional model of -1.6495 C, about 44% reduction at the same I, suitable for developing the mini refrigerator. The novel of this article is the practical methodology of using transient TEA to help design the PCP for specific purposes.
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    Effect of Nozzle Pressure and Shape Ratios on Gas Flow of a 122 mm Supersonic Rocket Nozzle investigated by CFD
    (2023-01-01)
    Chaiaiad, Chatchapat
    ;
    Thongsri, Jatuporn
    This article reports the effect of nozzle pressure ratio (NPR) and shape ratio (SR) on the gas flow of a 122 mm supersonic rocket, a convergent-divergent nozzle, using computational fluid dynamics (CFD). The NPR is the ratio between the pressure inlet and outlet, while the SR is the ratio between the outlet and throat areas of the nozzle. The CFD results revealed the gas flow, pressure (P), Mach number (M), temperature (T), shock, and jet for some conditions of NPR and SR, consistent with the theory. Furthermore, it was found that M increased with increasing NPR and/or SR. Furthermore, T enhanced with increasing NPR but decreased with increasing SR. This report can be used to further development of this nozzle type suitable for missions.