Development of Synthetic Jet Air Blower for Air-breathing PEM Fuel Cell
This paper presents a synthetic jet air blower actuated by PZT for air blowing for air-breathing micro PEM fuel cell. The several factors to affect the performance of air-breathing PEM fuel cell such as air flow rate, opening ratio and cathode open type in the cathode side were studied. Especially, an air flow rate is critical condition to improve its performance. In this paper, we developed a synthetic jet air blower to supply a high stoichiometric air flow. The synthetic jet mechanism is a zero mass flux device that converts electrical energy into the momentum. The synthetic jet actuation is usually generated by a traditional PZT actuator, which consists of a small cylindrical cavity, in/outlet channel and PZT diaphragms. The flow rate of the fabricated synthetic jet air blower was 400cc/min at 550Hz and its power consumption was very low under 0.3W. The proposed air-breathing PEM fuel cell which installed synthetic jet air blower was higher performance and stability during continuous operation than the air-breathing fuel cell without auxiliary device to supply the air. The results showed that the maximum power density was 188mW/cm at 400mA/cm. This maximum power density and durability were improved more than 40% and 20%, respectively. Keywords— Air-breathing PEM fuel cell, Synthetic jet air blower, Opening ratio, Power consumption.
Design and analysis of a compact synthetic-jet-based air pump for large airflow
In this paper, a compact synthetic jet actuator comprising a primary jet actuator and a synthetic jet chamber was proposed. This synthetic jet actuator can enhance the total airflow rate by combining the primary, and secondary flows synthesized by the synthetic jet. The oscillating diaphragm and valve parts of the synthetic jet actuator were designed as a closed magnetic flux loop to enhance the magnetic flux density in the coils. The primary jet actuator was designed with a separate inlet and outlet to serve as a heat-dissipation application and prevent the re-ingesting of heated air. Thus, a dynamic model of a synthetic jet actuator was constructed, and motion equations were subsequently derived using plate theory, the Lorentz law, and magnetic flux simulation. The behavior in association with the displacement of the oscillating diaphragm, oscillation frequency, and driving current is discussed in this paper. Finally, an experimental rig was constructed to verify the correctness of the airflow simulations. The synthetic jet actuator was integrated with flow channels, and achieved an airflow rate of 9.23 L/min at a 1.5 V driving voltage.
Methods of determining the desired frequency characteristics of the automatic control systems
Considered the methods of determining the desired frequency characteristics of the automatic control systems while the synthesis of their corrective devices.