摘要
毫米级微型拉伐尔喷嘴应用于微推进系统、超音速气流粉碎技术、激光切割等领域。确定微喷嘴基本参数后,根据可加工性要求,喷嘴选型和喷嘴扩张段长度直接影响到加工工艺难度,利用计算流体力学(computational fluid dynamics,以下简称CFD)分析方法,对不同类型和不同扩张段长度的喷嘴进行流场仿真,确立了本研究微喷嘴的选型规则和最优扩张段长度。结果表明:2维轴对称喷嘴相比矩形截面喷嘴具有较大的出口速度,建议毫米级喷嘴选型时采用2维轴对称喷嘴;对不同扩张段长度的2维轴对称喷嘴的流场仿真分析,通过对比喷嘴出口中心速度、推力及效率,表明在本研究条件下扩张段长为3 mm时是最优长度。CFD仿真分析方法可用于其它微型拉伐尔喷嘴的选型及扩张段长度的确定,研究有助于在保证喷嘴性能的前提下,降低喷嘴加工难度。
Micro laval no,zzle has been widely used in such areas as micro propulsion system, supersonic air-jet pulveriattion laser cUt- ting, etc. The gas flow characteristics for micro nogz｜es with different section shapes and different divergont section lengths were anayzed with the aid of computational fluid dynamics （CFD） simulation technology, which helped to determine the roles of nozzle type selection and the optimum divergent section length. The simulation results indicated that the exit velocity of two-dimensional axisymmetri~ nozzle is larger than that of rectangular section one, which shows that the two-dimensional axisymmetric type is recommended when the nozzlte is in millimeter level. The flow fields of the two-dimensi0nal axisytnmetrie nozzles with different divergent section lengths wore investi, gated through the comparison of their exit velocities, thrust forces and efficiencies, which presents that the optimal divergent length is 3 mm in this research. The proposed simulation method can be applied to the selection of other nozzle parameters and the optimization of length determination, which can hello to reduce the diffieuhv of manufacturabilitv of micro-nozzle with excellent oerformance.
出处
《四川大学学报（工程科学版）》
EI
CAS
CSCD
北大核心
2014年第1期200-205,共6页
Journal of Sichuan University (Engineering Science Edition)
基金
国家自然科学基金资助项目(50935003)
关键词
微型喷嘴
计算流体力学
推进性能
可加工性
micro nozzle
computational fluid dynamics（CFD）
propulsive performance
manufacturability
