内容提要: |
The influence of guide vane of exhaust (GVE), diameters of outer cylinder and diffuser, impeller geometric parameters, on a novel range hood aerodynamic performance is investigated in this report by computational fluid dynamic, which has different operation principle in comparison with other kind of traditional range hood with centrifugal fan. The pressure field and characteristic curves based on the dimensionless flow, pressure and power coefficients of the novel range hood are analyzed. Results show that the pressure and power coefficients first increase then decrease with the increasing number of GVE. It can help to improve the flow characterizes efficiently when the height of GVE is lower than 0.20 m, but the effect of GVE height on flow and pressure coefficients may be negligible at the height of GVE above 0.20 m. The pressure distribution in annular indicates that the diameters of outer cylinder and diffuser are 0.40 m and 0.320 m, respectively, which can effectively enhance the diffusion performance of the novel range hood. When blade inlet and outlet angular is smaller than 65° and 175°, the suction capacity of the novel range hood is enhanced with the increasing of inlet and outlet angular, respectively, based on the static pressure field in impeller and annular. As blade less than 28, the effect of blade number on coefficients of flow and pressure is remarkably. However, when the blade number is more than 30 blades, the characteristic curves for dimensionless flow and pressure coefficients exhibit downtrend simultaneously. In addition, the static pressure in blade passage of the impeller increases notably with the growth of blade height, when the blade height is lower than 0.200 m, while the improvement for static pressure is relatively minor when the blade height is higher than 0.200 m. |