## 1 Introduction  
Piezoelectric micropumps, driven by piezoelectric actuators, are characterized by high energy density, rapid response, absence of electromagnetic interference, and low energy consumption [1, 2, 3]. These attributes render them highly suitable for a broad range of applications in fields like biomedical engineering [4, 5], thermal management [6], microfluidic systems [7], and fuel cells [8]. Among the varieties of piezoelectric pumps, valveless piezoelectric pumps are favored by researchers due to their simple structure and lack of internal moving valves, which facilitate processing and miniaturization [9, 10]. However, the structural characteristics of valveless piezoelectric pumps also lead to issues such as high output backflow and inferior performance. To enhance the output performance of valveless piezoelectric pumps, extensive research has been conducted by scholars focusing on structural design, primarily involving the development of channels with differential flow resistance. Currently, channels with differential flow resistance commonly utilized in valveless piezoelectric pumps include diffusion tubes [11], Tesla tubes [12], Y-shaped tubes [13], vortex tubes [14], and heart-shaped tubes [15]. These channels exhibit resistance differences during the forward and reverse flow of fluids, thereby possessing unidirectional shut-off capabilities that can substitute for moving valves within valveless pumps. [PERSON] et al. [16] discovered that placing structurally asymmetric baffles within the pump chamber can also configure a valveless piezoelectric pump. Consequently, various types of baffles, such as conical [17], trapezoidal [18], hemispherical [19], and triangular [20] baffles, have been implemented in valveless piezoelectric pumps. In our team's previous research, an airfoil structure was introduced into a piezoelectric pump, resulting in the design of a high-flow valveless piezoelectric pump with airfoil baffles [21]. Experimental results indicated that with a driving voltage of 100 V, the maximum output flow rate of the valveless piezoelectric pump with airfoil baffles can reach 235.56 mL/min. Concurrent with structural design research on valveless piezoelectric pumps, researchers have also employed numerical computation methods to analyze the velocity and pressure distribution within the pump's internal flow field, as well as the pressure loss coefficients of the channels, with the aim of optimizing the structural dimensions of the piezoelectric pump and enhancing its output performance [22; 23; 24]. However, this analytical approach is incapable of pinpointing the exact locations where energy losses occur. In contrast, the entropy production method provides a means of linking unstable flow with energy losses, allowing for the precise calculation of the specific sites of energy loss. [PERSON] et al. [25] applied the entropy production method to conduct energy loss analyses on the hyperbolic channel, and subsequently optimized the structure of the flow-resistant differential channels based on the computational outcomes. The experimental results demonstrated that the output performance of the optimized piezoelectric pumps was significantly superior to that prior to optimization. However, the study focused solely on the optimization of the flow-resistant differential channels and did not encompass the entire piezoelectric pump. Therefore, to gain an in-depth understanding of the impact of airfoil angle of attack on the flow field structure within the channel and the output performance of piezoelectric pumps, this study positioned the Clark Y airfoil within the channel and designed valveless piezoelectric pumps with airfoil baffles at various angles of attack. Experimental studies were conducted to investigate the output performance of the valveless piezoelectric pumps with airfoil baffles at different angles of attack.