To solve the housing damage problem of a fractured compressor blade (CB) caused by an impact on the inner casing of a gas turbine in the seventh stage (from 15 stages), modifications of the trailing edge (TE) of the CB have been proposed, namely 6.5 mm curved cutting and a combination of 4 mm straight cutting with 6.5 mm curved cutting. The simulation results of the modifications in both aerodynamics variables Cl and Cd and the pressure ratio, including structural dynamics such as a normalized power spectrum, frequency, total deformation, equivalent stress, and the safety factor, found that 6.5 mm curved cutting could deliver the aerodynamics and structural dynamics similar to the original CB. This result also overcomes the previous work that proposed 5.0 mm straight cutting. This work also indicates that the operation of a CB gives uneven pressure and temperature, which get higher in the TE area. The slightly modified CB can present the difference in the properties of both the aerodynamics and the structural dynamics. Therefore, any modifications of the TE should be investigated for both properties simultaneously. Finally, the results from this work can be very useful information for the modification of the CB in the housing damage problem of the other rotating types of machinery in a gas turbine power plant.

A reflow soldering process (RSP) is generally implemented in advanced manufacturing factories for welding small electronic components together to create a product using heat generated at the welding tip (WT). Improper WT design and operating conditions may lead to defects in some products; therefore, optimizing both is immensely significant in developing the RSP. Accordingly, this article proposes a successful RSP development based on multiphysics in a hard disk drive factory consisting of transient thermal-electric and structural simulations. First, a new shape series WT was designed, and a conventional shape, parallel WT, was considered as a case study. Then, they were assembled and experimented with the RSP actual operating conditions to collect essential data. Next, the heat transfer was determined using a transient thermal-electric simulation (TES). The simulation results showed uneven WT temperatures depending on applied voltages, time, and shapes, which were consistent with the experimental results. The higher the applied voltage, the greater the temperature generated at the WT. Finally, after using TES results as loads, the structural simulation showed WT total deformations, which could be consistent with actually occurring defects. The findings from this research are a new design of series WT and proper multiphysics methodology for developing the RSP.

This article reports a successful development of the induction heating process (IHP) in a jewelry factory based on experiments and multiphysics consisting of electromagnetic and thermal simulations. First, two experiments were set to measure essential parameters for result validation and multiphysics boundary condition settings. Then, the essential parameters were applied to multiphysics, and both simulation results revealed heat transfer, magnetic flux density (B) generated by the coil, and temperature (T) of the product. B and T were consistent with the experimental results and theory, confirming the reliability of the multiphysics and methodology. After that, all simulation results were analyzed to assess and optimize IHP in terms of the number of coil turns (N), positional placement of the product (P), and coil thickness (Th). Multiphysics revealed that the current operating condition with N = 3 is proper; however, the IHP can be improved more with coil and operating condition optimizations. Finally, completing the optimizations, decreasing 40% of Th with N = 6, and the same P, increased B on the product by 21.62%, leading to IHP efficacy enhancement. The research findings are the optimum coil model and methodology for developing the IHP, which were practically employed in the jewelry factory.

No abstract