Experimental study on steady spray characteristics of diesel fuels containing dissolved CH₄

Investigation on steady spray characteristics of diesel fuels containing dissolved CH₄ was carried out. Spray characteristics and pattern were recorded by the particle size analyzer (LDSA1300A) and digital camera, respectively. Six straight-rounded-hole nozzles with different length/diameter ratio (L/D) were employed. The dissolving pressure was set from 0.1 MPa to 10 MPa, and the injection pressure was from 5 MPa to 10 MPa. The effects of the concentration of dissolved CH₄ in fuel, the measurement position, the injection pressure, and the nozzle parameter on the spray characteristics were investigated. The results show that, in the presence of dissolved CH₄ in diesel fuel, flashing injection phenomenon appears, and spray pattern and spray angle are changed remarkably compared with those of pure diesel fuel. Discharge coefficient decreases with the increase of CH₄ dissolved in diesel fuel and L/D value. Both positive and negative effects on atomization are observed due to the combined influence of the concentration of CH₄ and L/D value.