| Bladeless fan is well known as its unique style and efficient ventilation performance. Itssafety and creative design has a greater effect on the fan industry. In the present, few researchershave studied the whole bladeless fan at home and abroad, and structural improvements onbladeless fan progress also is not in depth. Therefore, the whole bladeless fan with itsperformance promotion becomes and key in the research.In the thesis, it takes bladeless fan as study object, establishes and simulates the wholebladeless fan and external fluid domain. Besides, it validates and interprets the flux multiple.Based on bladeless fan prototype, three types of turbo with splitter blades which equip differentinlet positions about bladeless fan are established, and three-dimensional numerical simulation isconducted for the models. From the results, analysis of internal and external flow fieldcharacteristics is done. In order to capture flow details and study the situation of curvature effect,different models by changing the curvature of Coanda surface are established, andtwo-dimensional numerical simulation is done for the models. What’s more, comparison andanalysis of the flow details for different two-dimensional models are performed. The optimumturbo model with splitter blade and Coanda surface model are integrated, thus an optimizedmodel is proposed. After three-dimensional simulation of optimized model, comparison withprototype and analysis of the flow details are performed. The main contents are as follows:(1) According to structural features of various sections on bladeless fan, targeted mesh isapplied. Different turbulence models are used to conduct numerical simulation. Additionally,design and numerical simulation for several types of bladeless fan models with differentcomputational domains are done. After comprehensive consideration, the suitable turbulentmodel and computational domain for bladeless fan are chosen. Numerical simulation is appliedto verify flux multiple about bladeless fan, and using formula elaborates reason of flux multipleabout bladeless fan from the theoretical perspective.(2) Three types of turbines with splitter blades which equip different inlet positions aboutbladeless fan are designed. Besides, simulation and study of internal and external flow fieldcharacteristics for them are done. Research results denote that: adding the splitter blades canimprove flow properties inside fan, which affects the flux variation;1/4chord length inlet modeland3/4chord length inlet model equip the best performance. (3) Within reasonable curvature limits, six types of Coanda surfaces models with differentcurvature are designed and simulated in two-dimension. By velocity, pressure, streamlines andso on, the result is analyzed, and the best model is found. Based on the trend, there is anoptimum curvature value in0.026~0.065in the Y direction, whose flow field equips with ahigher velocity and better flow characteristics.(4) The optimal inlet position model and best Coanda surface model are selected, whichwere integrated into an optimized model to simulate. And, comparison with prototype andanalysis on the flow details are performed. Data results show that: optimized model showsgreater flux and more stable flow in external flow field. And it shows better static pressure,velocity and so on in internal flow field, provides greater flow velocity for the external flow. |
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