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Item type:Item, A dual frequency ultrasonic cleaning tank developed by transient dynamic analysis(2021-01-02) ;Tangsopa, WorapolThongsri, JatupornAt present, development of manufacturer’s ultrasonic cleaning tank (UCT) to match the requirements from consumers usually relies on computer simulation based on harmonic response analysis (HRA). However, this technique can only be used with single-frequency UCT. For dual frequency, the manufacturer used information from empirical experiment alongside trial-and-error methods to develop prototypes, resulting in the UCT that may not be fully efficient. Thus, lack of such a proper calculational method to develop the dual frequency UCT was a problem that greatly impacted the manufacturers and consumers. To resolve this problem, we proposed a new model of simulation using transient dynamics analysis (TDA) which was successfully applied to develop the prototype of dual frequency UCT, 400 W, 18 L in capacity, eight horn transducers, 28 and 40 kHz frequencies for manufacturing. The TDA can indicate the acoustic pressure at all positions inside the UCT in transient states from the start to the states ready for proper cleaning. The calculation also reveals the correlation between the positions of acoustic pressure and the placement positions of transducers and frequencies. In comparison with the HRA at 28 kHz UCT, this TDA yielded the results more accurately than the HRA simulation, comparing to the experiments. Furthermore, the TDA can also be applied to the multifrequency UCTs as well. In this article, the step-by-step development of methodology was reported. Finally, this simulation can lead to the successful design of the high-performance dual frequencies UCT for the manufacturers. - Some of the metrics are blocked by yourconsent settings
Item type:Item, A novel ultrasonic cleaning tank developed by harmonic response analysis and computational fluid dynamics(2020-03-01) ;Tangsopa, WorapolThongsri, JatupornThe manufacturer of an ultrasonic cleaning tank (UCT) received advise from a customer to seek the cause to why the UCT could not clean their products effectively and develop a novel UCT to replace the conventional model. This UCT had a capacity of 10 L, a frequency of 28 kHz, four horn transducers, and a total power of 200 W. To resolve that problem and respond to customers’ needs, we presented new methods to develop the UCT using the harmonic response analysis (HRA) and computational fluid dynamics (CFD) to simulate the cleaning process which occurred within the UCT based on the actual conditions. Results from the HRA showed that the acoustic pressure in a problematic UCT was low, resulting in a smaller cleaning area, which was consistent with the results from the foil corrosion test, and thus caused the cleaning process to be ineffective. We developed a novel UCT with improved effectiveness by adjusting the design and adding a water circulation system. From the HRA, we were able to design the dimensions of the UTC and position of the transducer to be suitable to increase the acoustic pressure and cleaning area. CFD results enabled us to design proper inlet and outlet shapes, as well as simulate the water flow behavior to find the optimal cleaning condition so the novel UCT had a water circulation system that could eliminate the excess particles. - Some of the metrics are blocked by yourconsent settings
Item type:Item, Investigation of the trailing edge modification effect on compressor blade aerodynamics using SST k-ω turbulence model(2019-04-01) ;Kaewbumrung, Mongkol ;Tangsopa, WorapolThongsri, JatupornA gas turbine power plant in Thailand had the problem of compressor blade fracture in Stages 6-8, which was caused by housing damage. This gas turbine has a total of 15 stages. The housing damage reduced the lifetime of blades to an unacceptable level. This article shall report the solution and outcomes. Three-dimensional (3D) compressor blade models in the problematic stages were prepared by a 3D scanning machine to find a solution based on computational fluid dynamics (CFD), and then were completed for simulation by adding Stages 5 and 9 to become a multi-stage axial model. The latter models were modified by trimming the trailing edge by 1-, 5-, and 10-mm. Using ANSYS CFX R19.2 software, the CFD results of the trailing edge modification effect on flow using the shear stress transport (SST) k-ω turbulence model revealed aerodynamics inside the problematic stages both before and after blade modifications. Modifying the blade by 5 mm was suitable, because it had lesser effects on aerodynamic parameters: pressure ratio, drag, and lift coefficients, when compared to the modification of 10 mm. The larger the modification, the greater the effect on aerodynamics. The effects on aerodynamics were intensified when they were modified by 10 mm. The validation of base line blades was conducted for the overall compressor parameters that were compared with the measurable data. These results were accepted and gave positive feedbacks from engineers who practically applied our reports in a real maintenance period of gas turbine. - Some of the metrics are blocked by yourconsent settings
Item type:Item, Development of an industrial ultrasonic cleaning tank based on harmonic response analysis(2019-01-01) ;Tangsopa, WorapolThongsri, JatupornA small industrial ultrasonic cleaning tank, which is one of the best-selling models, had cleaning problems. Customers sometimes complained that the tank did not completely clean all objects, or that some objects got damaged, so a solution to the problem was urgently needed. The tank has a volume of 18 L, frequency of 28 kHz, eight horn style PZT4 transducers, and a total electric power of 400 W. The cleaning occurs from the cavitation effect which corresponds to an increase in the acoustic pressure. A computer simulation is presented using a harmonic response analysis (HRA) in ANSYS to resolve and improve the efficacy of the tank. From the simulation, we found that the acoustic pressure within the tank was uneven. The distribution of acoustic pressure had a characteristic pattern depending on the placement of the transducers. When the temperature was increased, the acoustic pressure was decreased leading to a cleaning efficacy drop as well. All simulation results were correlated to the foil corrosion test and power concentration experiment. The HRA was used to redesign the tank for higher cleaning efficacy. The simulation results indicated that more suitable placement of the transducers lead to a more intensified acoustic pressure, and a better distribution throughout the tank. This research not only resolved the cleaning problems that occurred in the 28 kHz tank, but was also demonstrated that it can be applied to a 40 kHz tank as well. Results from this research were accepted and approved by the manufacturer, and were used by them to develop smarter industrial ultrasonic tanks with higher cleaning efficacy for commercial sale.
