# Analysis of Flame Evolution Generated from Methyl Laurate Droplet Using Deep Learning
## 1 Introduction  
Biodiesel has emerged as a pivotal renewable energy source in the global transition toward carbon neutrality, offering reduced greenhouse gas emissions compared to conventional fossil fuels [1, 2, 3]. Among biodiesel constituents, methyl laurate--a saturated fatty acid methyl ester (FAME)--has garnered significant attention due to its favorable combustion properties, including its high cetane number and low viscosity [4, 5, 6]. Recent studies have highlighted its potential to mitigate soot formation and improve combustion efficiency in FAME [7, 8]. However, challenges relating to physical properties such as inconsistent atomization and incomplete combustion under varying operational conditions remain unresolved [9]. The combustion dynamics of fuel droplets are intrinsically linked to their evaporation, ignition, and flame stabilization processes Previous studies have demonstrated that droplet size and ambient temperature critically influence flame propagation speeds [10, 11]. Another study revealed the role of electric fields in enhancing biodiesel droplet atomization [12]. The evolution of fuel droplets is a critical phase in the combustion process, influencing overall combustion efficiency and emissions characteristics [13]. Within the framework of methyl laurate, the significance of droplet evolution is underscored by the fundamental understanding it imparts regarding the atomization, vaporization, and combustion characteristics inherent to biodiesel fuels. An examination of droplet evolution not only enhancesour comprehension of the biodiesel combustion processes but also provides valuable insights that can inform the engineering of combustion systems for optimal performance [14]. This knowledge is essential for addressing challenges related to fuel atomization, ignition, and combustion stability, contributing to the broader goal of enhancing the environmental sustainability of biodiesel. Studying droplet behavior and the progression of flames in methyl laurate is crucial for understanding the complex combustion processes of biodiesel fuels [7]. The flame evolution process encapsulates phenomena such as ignition, propagation, and extinction, each of which plays a pivotal role in determining combustion efficiency and emission characteristics [15; 16]. Examining the flame evolution of methyl laurate provides crucial insights into the ignition mechanisms specific to biodiesel constituents and the subsequent development of combustion flames. This knowledge is indispensable for optimizing combustion systems, enhancing energy extraction, and reducing pollutant emissions [17; 18]. The combustion characteristics of biodiesel droplets, such as ignition delay time and burning rate, significantly impact the overall combustion process [19]. These characteristics can influence the efficiency and emissions of biodiesel combustion [19]. For instance, studies have shown that blending biodiesel with diesel can lead to increased secondary atomization from the droplet, enhancing evaporation, mixing, and subsequently, combustion [20]. Furthermore, research on methyl laurate, a primary component of biodiesel, has revealed that its droplet combustion characteristics can be influenced by additives like Multi-Walled Carbon Nanotubes (MWCNT), which, due to their high thermal conductivity and good heat absorption ability, can lead to a shorter ignition delay time, higher droplet temperature, and better flame spread [21]. Additionally, the combustion characteristics of biodiesel droplets can also be influenced by the degree of unsaturation in the fuel. Increasing the unsaturation degree has been found to result in shorter ignition delay and burning duration but higher droplet temperature, burning rate constant, specific power output, and flame dimensions [8]. Therefore, understanding the droplet combustion characteristics of biodiesel, particularly methyl laurate, is crucial for optimizing its use as a fuel [8; 21].