This study investigates the phase change phenomena of cyclopentane fuel sprays under subcritical and transcritical conditions in a high-pressure, high-temperature chamber using optical diagnostics. Three optical techniques were employed to analyze the spray characteristics: shadowgraphy (SH), Mie scattering (MS), and infrared radiation (IR) measurements. SH and MS techniques revealed how quickly the phase transition from liquid to gas or supercritical fluid happens. MS results presented step-like transition behavior for subcritical sprays and smooth changes for transcritical sprays. IR measurements showed bimodal radial signal intensity distributions of transcritical sprays at downstream the liquid phase. Large signals at the spray boundary may indicate the onset of supercritical conditions. The findings in this study will support the development of computational models for phase transitions in fuel sprays. The results offer valuable data for optimizing combustion efficiency and reducing emissions in advanced combustion systems.     «

This study investigates the phase change phenomena of cyclopentane fuel sprays under subcritical and transcritical conditions in a high-pressure, high-temperature chamber using optical diagnostics. Three optical techniques were employed to analyze the spray characteristics: shadowgraphy (SH), Mie scattering (MS), and infrared radiation (IR) measurements. SH and MS techniques revealed how quickly the phase transition from liquid to gas or supercritical fluid happens. MS results presented step-lik...     »