# Venturi Injector Optimization for Precise Powder Transport for Directed Energy Deposition Manufacturing Using the Discrete Element Method and Genetic Algorithms

## TL;DR

This paper optimizes Venturi injectors for precise powder transport in 3D printing using simulations and genetic algorithms to improve performance in low-pressure systems.

## Contribution

A novel optimization approach combining discrete element method simulations and genetic algorithms for Venturi injectors in low-pressure powder transport.

## Key findings

- Optimal Venturi injector dimensions achieved an 85% improvement in powder suction compared to initial designs.
- The most influential design variables were suction diameter (D3), throat diameter (d2), and nozzle diameter (d1).
- The optimized design resulted in a maximum 2% loss of load during powder transport.

## Abstract

Additive manufacturing technologies such as directed energy deposition use powder as their raw material, and it must be deposited in a precise and controlled manner. Venturi injectors could be a solution for the highly precise transport of particulate material. They have been studied from different perspectives, but they are always under high-pressure conditions and mostly fed by gravity. In the present study, an optimization of the different dimensional parameters needed for the manufacturing of a Venturi injector in relation to a particle has been carried out to maximize the amount of powder capable of being sucked and transported for a specific flow in a low-pressure system with high precision in transport. For this optimization, simulations of Venturi usage were performed using the discrete element method, generating different variations proposed by a genetic algorithm based on a preliminary design of experiments. Statistical analysis was also performed to determine the most influential design variables on the objective, with these being the suction diameter (D3), the throat diameter (d2), and the nozzle diameter (d1). The optimal dimensional relationships were as follows: a D3 34 times the particle diameter, a d2 26.5 times the particle diameter, a d1 40% the d2, a contraction angle alpha of 18.73°, and an expansion angle beta of 8.28°. With these proportions, an 85% improvement in powder suction compared to the initial attempts was achieved, with a maximum 2% loss of load.