Biomass cookstoves remain a major source of household air pollution in many developing regions, where traditional designs often exhibit inefficient heat utilization and high emissions of PM, CO₂, and CO due to incomplete combustion. Despite extensive prior research, the novelty of this study lies in its systematic CFD-based comparison of different combustion chamber geometries under identical operating conditions to identify an optimized improved cook stove design. This study applies computational fluid dynamics (CFD) to optimize the geometry of combustion chambers in improved cookstoves, targeting enhanced energy efficiency and reduced pollutant formation. Using ANSYS Fluent, three-chamber configurations were evaluated through their temperature, velocity, and species distributions. The comparative analysis of temperature distribution and flow characteristics across the three geometries reveals that the cylindrical chamber shows the weakest performance, marked by steep thermal gradients, limited flow acceleration, and elevated concentrations of volatiles, soot, and NO. The cone-type combustion chamber offers balanced performance by harmonizing temperature distribution, flow velocity, and effective heat transfer within the combustion zone. Unlike the cylindrical chamber, it minimizes wall losses and dead zones and avoids excessive gas acceleration, which can reduce effective heat utilization. This geometry also provides steady heat transfer and moderate acceleration while maintaining a stable and uniform thermal field, making it well-suited for applications that prioritize consistent combustion and controlled temperature distribution. The converging nozzle type chamber produced a stable high-temperature core, a strong attached flow, and substantially cleaner combustion. These outcomes underscore the pivotal role of chamber geometry in determining oxidation completeness, heat transfer effectiveness, and emission performance. CFD results indicate that the converging-nozzle design enhances combustion by increasing flame temperature (15–25%) and flow velocity (30–40%), while reducing NO, soot, and volatiles by up to 50% compared with the conventional cylindrical chamber. Hence, the optimized converging-nozzle design demonstrates clear potential for next-generation improved cookstoves by enabling enhanced heat transfer and lower environmental impact.
Feto et al. (Mon,) studied this question.