A needle-free automatic injection syringe is a device that delivers drugs into the skin and tissues using a high-speed fluid jet without using an injection needle. This technology is attracting attention as an efficient means of vaccine delivery in the veterinary and livestock fields that reduce the risk of cross-infection and require mass vaccination. In particular, animal vaccination provides various advantages over conventional needle injection methods in terms of worker safety, inoculation speed, and maintenance cost. Among these drivers, Jet Injector Nozzle's flow path design is very important in needleless automatic injection syringes. This paper was conducted to solve the problem of pressure loss at the nozzle discharge side of the existing Jet Injector in designing the flow path of the animal vaccine-free automatic injection syringe nozzle. To this end, CAE was performed and the optimum design of the flow path required by the company was performed, and a large flow rate was possible in the optimal shape design, but this focuses on the nozzle flow path, which requires a review of design additions of cylinders and motors on the rear side.

Abstract
1. 서 론
2. 연구 내용
    2.1 상세 연구 내용
    2.2 설계 조건
3. 해석 및 고찰
    3.1 연구의 개요
    3.2 기존 형상의 분석
    3.3 기존 형상
    3.4 기존 형상 해석 결과
    3.5 도출된 최적 형상
    3.6 최적 형상 해석 결과
4. 결론 및 향후 과제
References

• 이정익(INHA Technical College, Dept. of Mechanical Design) | Jeong-Ick Lee Corresponding author