Theoretical And Experimental Research On Valveless Piezoelectric Pump With Flow Resistance Difference Tubes

Valveless piezoelectric pump with flow resistance difference tubes has no moving valve body, and no additional components except for mechanical structure. That makes the pump have the advantages of simple structure, high reliability, long operating life, low noise and low cost and so on. Therefore, this type of piezoelectric pump has great developments and improvements in recent years, and has broad application prospects on precision micro fluid transfer and actuating system. Existing designs of valveless piezoelectric pumps based on flow resistance difference are mainly on basis of diffuser/nozzle or Tesla-tubes, which can only be used for fluid transfer. This single structure and function leads to the limited applications, which makes the pump hard to achieve a wide practical application and commercialization. For this reason, strengthening the research efforts of valveless piezoelectric pump with flow resistance difference tubes and accelerating the industrial development of valveless piezoelectric pump will promote the development of related high-tech industries effectively in our country. This project is supported by National Natural Science Foundation of China(NSFC, Grant No.51075201) and major research plan of National Natural Science Foundation of China(Grant No. 91223201). Taking valveless piezoelectric pump with flow resistance difference tubes as the research object, the study on new type actuate mechanism, equivalent circuit model, performance simulation and pump performance test of valveless piezoelectric pump with flow resistance difference tubes was carried on. This paper proposed 4 types of valveless piezoelectric pump with flow resistance difference tubes, aiming to satisfy the requirements for integrated and diversified fluid transfer system in areas like biomedicine, fine chemistry and electronic chip cooling. Meanwhile, according to the research on these 4 types of piezoelectric pump, the reliability and accuracy about the equivalent circuit model of valveless piezoelectric pump with flow resistance difference tubes was proved, which provides new guidelines for the design of this type of valveless piezoelectric pump. The main research contents and results are as follows:1. Currently piezoelectric pumps were classified according to the presented classification method based on the structural type and operating principle of piezoelectric pump. The research process and application of piezoelectric pump in the domestic and overseas were analyzed systematically. Additionally, the specific structure type and application objective of the valveless piezoelectric pump with flow resistance difference tubes for this project was presented definitely.2. The energy transfer analysis of piezoelectric pump was carried on, and the common energy transfer law followed by various types of piezoelectric pumps was obtained. Therefore, the key problems, such as the various performance indicators and evoked elastomer deformation mechanism of piezoelectric ceramics, flow resistance characteristics of tubes, and the operating principle of valveless piezoelectric pump with flow resistance difference tubes, were summarized systematically. And then the operating principle of piezoelectric vibrator and the formation mechanism of flow resistance difference tubes working as the no moving valve body was explained. Finally, the flow characteristics of valveless piezoelectric pump with flow resistance difference tubeswas also explained.3. The correctional dynamical model of valveless piezoelectric pump with flow resistance difference tubes and the analogy analysis method based on similarity system theory was established. And the equivalent circuit model of valveless piezoelectric pump with flow resistance difference tubes considering the nonlinear flow resistance factors caused by flow resistance difference tubes was studied. That makes it intuitively and systematically to explain the structure parameter effects on pump flow rate. Meanwhile, the direct link between flow path parameter and circuit parameter brings about enhancement of the intuition and relative property, the decrease of analysis difficulty, and the improvement of analysis efficiency, which provides the effective analysis method for the design of new types of valveless piezoelectric pump based on flow resistance.4. A new type of Y-shape various cross-section flow resistance difference tubes was presented, and then a new type of valveless piezoelectric pump based on Y-shape various cross-section tubes was designed. The operating principle of valveless piezoelectric pump based on Y-shape various cross-section tubes was analyzed. Through the flow field analysis of tubes and pumps, the flow resistance difference effect relational expression of tubes on pump flow rate was obtained. On basis of the pump flow rate testing results and the equivalent circuit model calculating results, the effectiveness and reliability of the equivalent circuit model for the valveless piezoelectric pump with flow resistance difference tubes was verified, which provides a convenient method to design this type of valveless piezoelectric pump in turn.5. A new type of Y-shape topology tube was presented, and then 2 types of valveless piezoelectric pump based on Y-shape multistage bifurcate tubes are designed. The operating principle of the tube and pump was analyzed, which provides new method for the design of functionally diverse valveless piezoelectric pump with flow resistance difference tubes. Meanwhile, this method also can be used for other types of piezoelectric pumps. Taking advantage of the testing result of the two types of pumps, the reliability of the equivalent circuit model for the valveless piezoelectric pump with flow resistance difference tubes was further verified, and the measures to be taken to improve the model were proposed.6. The fractal character of Y-shape topology tube was confirmed, and the changing relationship between pump flow rate and tube diameter distribution fractal dimension was established. Through the flow field simulation analysis and experiment research on tubes and pumps, the changing law between tube structure and pump output was obtained, which offers the important theory basis for this type of valveless piezoelectric pump with flow resistance difference tube in application on electronic chip cooling.