Experimental and Numerical Analysis on Noise Characteristics of Parallel Multiple Jets Obliquely Impinging on a Flat Surface in the Steel Slab Scarfing

Abstract

Scarfing applications cause severe noise pollution in metallurgical engineering. To determine the noise characteristics generated by parallel multiple impinging jets in the slab scarfing process, a physical experiment is performed, and a 3D mathematical model is established. Mutual attraction of the parallel multiple jets is recorded, and its influence on the acoustic properties is revealed. The effects of impact height, impact angle, and Reynolds number on the multi‐jet impingement are analyzed. The results indicate that the parallel multiple jets combine in pairs in the upstream. The multi‐jet impingement increases the magnitude of dipole acoustic source, and the noise directivity presents two peaks above the impacted surface. As the impact height increases, the noise intensity first increases to later decrease, and the noise propagation is deflected along the axial direction. As the impact angle decreases, the noise intensity gradually increases, and the spectrum shifts toward higher frequencies. The jet Reynolds number only affects the noise intensity, but has little influence on the spectrum and directivity. The results of this research may provide a theoretical basis for the formulation of guidelines to reduce noise pollution in slab scarfing processes.