An Investigation on Characteristics of Spray Combustion Under GCI Engine Conditions Using Gasoline–Biodiesel Blends

In this study, mixtures of high-octane gasoline–biodiesel (GB) rating from 0% to 20%, denoted as GB00-GB10-GB20, were chosen to be experimented under simulated gasoline compression ignition (GCI) engine inside a constant volume combustion chamber (CVCC) before making comparisons about spray and combustion characteristics. While typical data of the nonvaporization spray characteristics: spray penetration length, spray cone angle, and spray evolution were collected by varying 40–90 MPa of injection pressure at 15 kg/m³ ambient gas density, data representing combustion characteristics, namely the ignition delay, flame development, and heat release rate (HRR) were illustrated under 90 MPa injection pressure, same ambient gas density, and temperature variation of 900–1000 K. Although the fuel mixture spray development trends followed a similar pattern, GB10 and GB20 had an averagely 6.25%–7.7% faster impingement velocity than that of GB00 except for the lowest considered injection pressure. Additionally, the ignition delay reductions were recognized for both GB10 and GB20, with the duration dropping from 1.09 to 1.06 ms and 0.96 to 0.79 ms, respectively. The results for spray and combustion characteristics under GCI engine condition-like showed a close relationship, offering valuable insights for simulation, spray, combustion, and ANN modeling, thereby supporting the development and application of GCI engines.