## 1 Introduction  
Coal mining is one of the important industries and plays a significant role in the national economy of Vietnam. According to the development plan for the coal industry, coal production is projected to be 51-54 million tons by 2025 and 55-57 million tons by 2030. Consequently, increasing coal production has led to significant challenges in environmental and occupational health aspects due to the expansion of large-scale mining operations. Vietnamese underground coal mines commonly employ the drilling and blasting method for roadway construction as this approach is well-suited to geological conditions and offers cost savings. However, a high concentration of dust is generated during the blasting process. The high concentration of coal dust is the primary cause that not only affects the progress of tunnel construction and safety but also poses a serious threat to the workforce. Coal dust arises during the drilling, blasting, and transportation phases in the construction of tunnels. The majority of dust emissions result from the blasting process, with dust particle sizes varying widely and differently, leading to air pollution within the mining environment and posing a significant impact on the health of the workers. Furthermore, coal dust also exists in the form of suspended particulates in the mine air, comprisingfine particles, especially those with sizes smaller than 10 \(\upmu\)m. These particles have the potential to penetrate deep into the respiratory tract and come into contact with the lungs, leading to respiratory issues and other health-related concerns. Workers operating in prolonged mining environments are at risk of contracting respiratory diseases, such as lung inflammation, due to exposure to dust. Currently, the cases of pneumoconiosis among underground coal miners in the Quang Ninh region comprise 1228 individuals, and it is projected to rise to over 1400 individuals in the future without effective dust control measures. Hence, researching the ventilation parameters that influence the dispersion pattern of dust during blasting in tunnels and controlling the elimination of coal dust is highly essential. In Vietnam, several studies have been conducted: The authors in [1,2] conducted research and designed a dust control system using an air and water mixing box to generate fine water droplets. In [3], the authors proposed a solution involving mist spraying to protect laborers. However, the dust dispersion pattern in tunnels has not been determined; thus, the effectiveness of the dust reduction solution has not been high. In recent years, Computational Fluid Dynamics (CFD) has become a pivotal technology in simulating and analyzing dust dispersion in mining environments. CFD modeling allows for the detailed study of air and dust particle movements within tunnels. Notable international research includes analyses of dust concentration distribution and particle sizes at mechanized coal mining faces, numerical simulations of airflow patterns, and the dust distribution in tunnel excavations using solid-gas flow equations such as those in Geng [4]. Using Computational Fluid Dynamics (CFD) to study the movement patterns of dust in coal mines, the authors in [5] analyzed particle sizes and the distribution of dust concentration at the fully mechanized longwall. [PERSON] conducted numerical simulations on airflow patterns and the distribution of dust concentration within constructed tunnels [6]. [PERSON] conducted simulations of airflow patterns within tunnels with long blind headings using three-dimensional (3D) numerical simulation technology, obtaining a preliminary correlation between airflow patterns and dust movement [7]. [PERSON] simplified the similarity criteria in the simulated tunnel excavation process using an approximate modeling method employing the two-phase solid-gas flow equations and subsequently determined the dust distribution pattern during excavation through experiments [8].