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Optimizing the hydraulic efficiency of submersible drainage pumps (SDPs) is crucial for energy conservation and performance enhancement, especially in emergency applications. Therefore, this study aims to develop an energy-efficient SDP by designing an optimized impeller model using a numerical scheme and introducing a flow balance block (FBB) as an alternative to modifying the pump casing, thereby reducing internal space and improving performance. Experimental validation of the optimized impeller and FBB was conducted by comparing their performance with the original pump model. The results demonstrated that the optimized impeller increased efficiency by 3.35% at a flow rate of 0.195 m3/min, with an overall average efficiency improvement of 2.33%. Additionally, when the optimized impeller and FBB were combined, the pump's efficiency was further enhanced by 5%, and the flow rate increased by approximately 10%. The study also proposed that the tap bolt method is more effective for installing the FBB than the silicone attaching method. This research provides a comprehensive experimental approach to improving SDP efficiency and offers valuable insights for future pump optimization. [ABSTRACT FROM AUTHOR]

Several studies have investigated predictive factors such as morphological, physiological, and fluid dynamics perspectives for obstructive sleep apnea (OSA) using computed tomography imaging, computer simulations, and experiments. Computational fluid dynamics is used in this study to analyze airflow in the upper airway across different body mass index (BMI) groups to identify suitable factors for predicting OSA. A comparative analysis is conducted on three groups: normal BMI (22.8 ± 1.0), overweight BMI (31.8 ± 1.5), and OSA (28.6 ± 3.3), with nine participants in each group. Geometric parameters were analyzed in addition to fluid dynamics factors. A comparison of the geometric variables revealed that the OSA group had the shortest total airway length (1.5 × 10−1 m) and the smallest volume (5.4 × 10−5 m3). However, t-test results showed low statistical significance for these differences. For fluid dynamics variables, the OSA group experienced the highest pressure drop (−46.8 Pa) and the highest adjusted pressure coefficient (Cp = 0.88) compared to the other two groups. From the analysis of breathing diagrams, the OSA group exhibited the largest area under the breathing power curve (32.6 × 10−3 N m/s) followed by the normal weight (24.9 × 10−3 N m/s) and overweight (21.0 × 10−3 N m/s) groups in descending order. Analysis of fluid dynamics factors indicated that the OSA group exhibited significantly higher pressure drop and pressure coefficient values compared to other groups although the differences between the groups were less significant. Finally, one key finding from this research highlights a new computational approach that relies on the breathing diagram. This new approach could provide more accurate insights into predicting and managing OSA due to their distinctive shapes. [ABSTRACT FROM AUTHOR]

Submersible drainage pumps are used around the world both residentially and industrially for draining water and sewage. However, these pumps are prone to wear and clogging when the flows inward contain particles and air bubbles, and the combined effects of cavitation and erosion directly affect the performance of such pumps and degrade their efficiency. Therefore, it is essential to design a submersible pump that mitigates the adverse effects of cavitation and erosion. Reported here is an energy-efficient submersible drainage pump for use in emergency response. The combined cavitation–erosion effects are established in order to reduce their adverse impact on the pump, and how erosion wear affects the cavitation characteristics of the water in the pump is investigated. An experiment was conducted to verify the numerical results pump, and then, the influences of particle concentration and size on two-stage existing and altered model submersible pumps were analyzed using computational fluid dynamics. The results show that the performance of the altered model pump increased by 4.34%, with the cavitation–erosion effects reduced significantly. In addition, higher particle concentration induced higher erosion rates at both the leading and trailing edges of the impeller blades. Furthermore, the altered model significantly reduced the cavitation–erosion impact on the pump impeller blades compared to the existing model. [ABSTRACT FROM AUTHOR]