| Summary: | 碩士 === 國立屏東科技大學 === 車輛工程系所 === 105 === In order to avoid these limitations, ex: backpressure or cut speed in high speed, this study carried out a new type of tubular wind collection device. The exit configuration is a backward-facing step geometric that causes the inflow through the duct and induced a local low pressure zone at the stepped incision groove. It is produced a pressure drop to induce the suction effect by the relative pressure difference between the channel and the outlet.
In this study, the finite volume method is applied to solve the Navier-Stokes equations, and the steady-state flow field analysis is carried out with the Realizable k-ε turbulence model. The height of the exit groove is changed (0D ~ 4D), and the effects of different inlet wind speed (5m/s ~ 12.5m / s) on the inlet were discussed.
The result shows that increasing the groove cutting height increases the local low pressure zone at the outlet, and the low pressure vortex increases. The mass flow rate is increased by more than 3 times, and as the entrance wind speed increases. For the 3D height increased to 4D process, the flow rate is only slightly increased. In addition, the optimal height of the groove is increased by the increase in wind speed. For the flowfield phenomenon, backward-facing step flow and cylinder flow are interaction. The suction effect is the best while the cylindrical rear produces a stable symmetrical vortex system.
Keywords: Cut-off Wind Speed，Backward-Facing Step，Wind Collector， Groove Cutting，Finite Volume Method
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