Full
Outline
In order to provide theoretical guidance for pipeline layout and optimized operation in engineering design, and reduce building operation energy consumption, the variations in local resistance coefficients, fluid motion states, and viscous dissipation of elbows under different pipe diameters and velocities were compared by the method of combining the experiments and numerical simulation, and the groove method was utilized to optimize the components of the elbows. The results reveal that as the pipe diameter increases, the influence of deformed components on the fluid within the elbow gradually decreases, and the area of the low-velocity zone in both the turning section and downstream straight pipe section gradually decreases. At an inlet velocity of 1.1 m/s, elbows of varying diameters exhibit deviations from the established power function law regarding local resistance coefficients. Specifically, elbows ranging from DN40 to DN65 demonstrate nearly identical resistance coefficients, as do those from DN100 to DN125. This phenomenon is attributed to the internal fluid dynamics and stress distribution within the elbows. Using the aforementioned theoretical study for component optimization, adding grooves in the separation area of the material wall can reduce the local resistance loss of the elbow, reduce the range of low-velocity areas, and reduce mechanical energy consumption as well. In the elbow with added grooves, the optimization of local resistance is most significant at a smaller inlet flow rate of v=0.5 m/s, the local resistance is reduced by 63.96%. These research findings offer valuable insights for the design layout and structural optimization of elbows in engineering applications.
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| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
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