Design, simulation and experimental validation of a single-shot piston burner for adjustable diesel PM generation toward confined space deposition

Diesel combustion particulate matter (PM) poses severe environmental and health risks, but the laboratory-scale batch-type, quantitative, and stable generation of diesel PM remain challenging due to the lack of dedicated generators. Here a single-shot piston burner was proposed, enabling on-demand batch-type production of diesel PM with adjustable yield. The burner integrates a pressure-atomizing fuel injection unit, a high-voltage arc ignition module, and a ball-screw-driven piston transport assembly within a semi-enclosed cylindrical combustion chamber. A three-dimensional transient combustion model was developed to simulate the coupled effects of injection duration and nozzle geometry on temperature distribution and soot formation. Simulation results reveal that injection duration governs heat accumulation and soot concentration, while nozzle diameter critically affects temperature field uniformity. Based on simulation, the 0.3 mm nozzle achieves the most balanced performance, yielding an average chamber temperature of 971 K and soot concentration of 180 mg/m 3 . Experimental validation was subsequently conducted under selected operating conditions using the 0.3 mm nozzle. Thermal imaging diagnostics reveal a limited overall shell temperature rise and regular fan-shaped exhaust thermal footprint, verifying reasonable heat dissipation and predictable exhaust transport behavior. Experiments demonstrate that total PM yield is positively correlated with injection duration, whereas piston feed speed determines the temporal stability of PM output, with a moderate speed of 1.5 cm/s minimizing concentration fluctuation. The proposed burner enables adjustable PM generation, supporting controlled studies of PM transport, deposition and environmental behavior in confined spaces. Future work will investigate the burner's performance with biodiesel, alcohols, and other liquid fuels, along with comprehensive PM characterization including size distribution, morphology, composition, and repeatability.