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.

A needleless automatic injection syringe (Jet Injector) is a device that delivers drugs into the skin and tissues using high-speed fluid jets without the use of injection needles. Jet Injector's core technology is to penetrate the stratum corneum of the skin by converting pressure energy generated in the driving unit into fluid kinetic energy, and structural loads and dynamic responses generated in this process directly affect the performance and durability of the device. Therefore, the structural mechanical design of the drive unit can be said to be a key factor in securing the reliability and injection accuracy of the Jet Injector. This paper is intended to provide the basis data for the basic design of the drive unit of the "Animal Vaccine-free Automatic Injection Syringe (hereinafter referred to as the "Jet Injector"), and this calculation data provides basic data for the design. Based on this, it is possible to design the drive unit according to various assumptions and given conditions, and the expected performance can be reasonably inferred according to the design.