Analysis of Gas Flow Dynamics in Thermal Cut Kerf Using a Numerical and Experimental Approach for Nozzle Selection

• Published in: Processes Vol. 10; no. 10; p. 1951
• Main Authors: Tuladhar, Upendra, Ahn, Sang-Hyun, Cho, Dae-Won, Kim, Dae-Hwan, Ahn, Seokyoung, Kim, Seonmin, Bae, Seung-Hoon, Park, Tae-Kook
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.10.2022
• Subjects: Consistency; Cutting; Design and construction; Flow distribution; Gas flow; Image processing; K-omega turbulence model; Kerf; Lasers; Mathematical models; Methods; Nozzle geometry; Nozzles; Nuclear energy; Nuclear power plants; Pressure distribution; Radiation; Turbulent flow; Velocity; Visualization; South Korea
• ISSN: 2227-9717; 2227-9717
• DOI: 10.3390/pr10101951

Consistency in gas flow behavior under various operating conditions is expected for uniform cutting performance in the thermal cutting process. The slope of the cut front in the kerf slot of a sample cutting material varies with the operating condition which affects the gas flow pattern. Therefore, how the nozzle exit diameter and the slope of the cut front effects gas flow behavior has been studied using the Reynolds averaged Navier–Stokes (RANS) based k–ω turbulence model. Convergent–straight-type nozzles with exit diameters φexit of 1.5 mm, 2 mm and 2.5 mm were used to study the flow patterns through the kerf slots of variable cut front slopes. The numerical simulation results were then compared with the results obtained from the Schlieren experiments. In addition, image processing was performed in the Schlieren images for clear visualization and precise comparison of the numerical and experimental data. The results confirm that a nozzle with an exit diameter of 2 mm shows a higher consistency in flow behavior in variable operating conditions.