Influence of atomizing core on droplet dynamic behavior and machining characteristics under synergistically enhanced twin-fluid spray

Abstract

The droplet dynamic behavior of spraying during the manufacturing process affects tool life, cooling, and lubrication. A detailed understanding of droplet dynamic behavior is required to improve the surface quality while reducing the cutting fluid consumption. In this study, quantitative measurements for droplet diameter, number concentration, and axial velocity were carried out through a phase Doppler particle analyzer technique. The droplet characteristic spatial distributions of a standard twin-fluid nozzle (STN) and a novel twin-fluid nozzle (NTN) under different gas-to-liquid mass ratio (GLR) values were analyzed in detail. The results showed that the high-speed internal gas flow of an atomizing core has a significant effect on improving the synergistically enhanced atomization behavior, and more smaller droplets and an increased droplet momentum are easily obtained. Furthermore, a better spatial distribution of atomization characteristics can be achieved under a higher GLR of 4.3%. Furthermore, the effects of the novel atomizing core structural parameters on the droplet mean velocity spatial distribution, droplet turbulence, and root mean square velocity fluctuation were investigated. The results also showed that the improved NTN can effectively improve the spray atomization performance and droplet dynamic characteristics. In addition, comparative studies of the effect of the atomizing core structure on the machining performance were performed. Compared with the STN, the improved NTN achieves a significant reduction in cutting temperature, tool wear, and surface roughness of 17.25%, 33.96%, and 37.83%, respectively, owing to the better droplet dynamic characteristics and spatial distribution of spray atomization characteristics.

Multi-Physics Coupled Acoustic-Mechanics Analysis and Synergetic Optimization for a Twin-Fluid Atomization Nozzle

“…To analyze the influence of various working parameters on the atomization flow field, the flow field distribution of the TFN was obtained using a multi-physics coupled acoustic-mechanics model. Previous studies have shown that the spray velocity has an important influence on both the particle size and distance, with a higher spray velocity favoring droplet breakup, resulting in a smaller overall droplet size and a longer spray distance [23]. Therefore, the water flow rate was selected as the variable for analyzing the effect of the water flow rate variation on the overall atomization flow field characteristics, and the effect of the water flow rate variation on the spray velocity was investigated.…”

“…However, a multi-parameter and multi-objective analysis of the overall structure of a TFN is key to improving its efficiency. In our previous work, Chen et al [23,24] analyzed and compared the effects of self-excited vibrating cavity (SVC) on the spray performance of TFN using the phase Doppler method. Numerical analysis and comparative experiments on twin-fluid atomization nozzles under different parameter conditions were conducted, and the effects of different gas-liquid pressure ratios and structural parameters on the atomization performance were studied in detail.…”

Automatic trajectory generation for metal surface droplet coloring

“…3. First, the contact shape of a droplet is assumed to have an approximately spherical contact shape [16,17] with contact radius δ1 at the time that it reaches the metal surface (see Fig. 3(a)).…”

Fuel Flowrate Control for Aeroengine and Fuel Thermal Management for Airborne System of Aircraft—An Overview

“…As the most expensive hydraulic control component, electro-hydraulic servo control valve [50] has an impact on the performance of FCS. Chen et al [51] investigated that the factors influencing the property of FMU were the input current, servo fuel pressure, and direction of movement of fuel metering valve. Meanwhile, the effects of back pressure and other nonlinear factors on pressure difference across metering valve have been researched.…”