PDF(Pubmed)
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.
摘要：
诸如定向能量沉积之类的增材制造技术使用粉末作为原材料，它必须以精确和受控的方式存放。文丘里注射器可以是用于颗粒材料的高精度输送的解决方案。他们从不同的角度进行了研究，但它们总是处于高压条件下，主要靠重力喂养。在本研究中,例如,已经对制造文丘里注射器所需的与颗粒相关的不同尺寸参数进行了优化,以使能够在具有高输送精度的低压系统中被抽吸和输送以用于特定流的粉末的量最大化。对于这种优化，使用离散元方法对文丘里管的使用进行了模拟，根据实验的初步设计，通过遗传算法生成不同的变体。还进行了统计分析，以确定对目标最有影响力的设计变量，这些是吸入直径（D3），喉部直径(d2)，和喷嘴直径(d1)。最佳尺寸关系如下：D3是颗粒直径的34倍，d2是粒径的26.5倍，d140%d2，收缩角α为18.73°，膨胀角β为8.28°。有了这些比例，与最初的尝试相比，粉末吸力提高了85%，最大2%的负载损失。
