Fuzes Airflow The Piezoelectric Generators Airflow Control Inlet Turbulence Numerical Simulation Studies

The pneumatic piezoelectric generator of fuze has a new power generation method based on the piezoelectric effect. It will continue to change the mechanical energy of vibration to electrical energy for supplying the fuze. The generator has many advantages such as simple structure, small volume, high reliability, high transduction power, easy to storage and so on. They make it the first choice for high power and small volume fuze. Its inlet flow field properties have close relation with resonant power working process, and its internal flow field will change while the inlet parameters of mechanism change, therefore, the relationship between the variation process of the flow field and the structural parameters is critical for airflow generator successful generating. Apply computational fluid dynamics method for numerical simulation of inner flow field, and analyse the effects of air inlet structure parameters on the flow field, predict the control of air inlet structure, provide technical support for inlet engineering design.The geometry characteristic of the inlet structure affects the inlet velocity distribution seriously. According to the new pneumatic piezoelectric generator scheme of fuze and the resonant generation principle driven by ring shape airflow, this paper design two inlet structures for ring gap, one is straight inlet and the other one is contraction form inlet. Through the computational fluid dynamics method, we caculate the related parameters of the flow field in the inlet using three dimensional numerical simulation. The results show the streamlines charts, speed vector maps, pressure equivalence value maps and so on of the inlet flow field in both two kinds of structure scheme. After comparison, we choose the ring shape contraction form inlet because it can turn the flow to turbulence nearer to the intake and make the velocity field distribution uniformity and get the flow velocity in the outlet faster.Do some preliminary research on the ring gap contraction inlet structure form. Through comparing the flow field velocity distribution with different dimensions of the structure, analyze the relationship between the inlet length, diameter size and the flow field in velocity distribution. The results show that, the length of development part effect the internal flow field velocity distribution chiefly, and the influence of the turning part length and intake diameter size on the internal flow field velocity distribution can be ignored.This research method and the results provide certain theoretical basis to the research on pneumatic resonance mechanism of this new fuze pneumatic generator. The paper is good for the further research and design work of the generator inlet structure.