Experimental study on spray characteristics of octanol biodiesel and modification of spray tip penetration model

In this paper, the effects of octanol on the spray characteristics of biodiesel are investigated. Four kinds of blends fuel are used to explore the variation of spray tip penetration, spray cone angle, spray area, and spray tip velocity under different injection pressure and environmental pressure conditions. In addition, this article also uses the experimental data to verify the model of Hiroyasu and Arai. The results showed that with the increase in octanol proportion, the spray tip penetration decreased at first and then increased while the spray cone angle and the peak tip velocity increased at first and then decreased. Only the spray area increased gradually. Among various fuels, the blended fuel with 30% octanol has the longest spray tip penetration and the largest spray area, while the blended fuel with 20% octanol has the largest spray cone angle. The prediction data of the Hiroyasu and Arai model is greater than the experimental data. Therefore, this article revises the model by introducing the density term, viscosity term, and the correction factor. Compared with the Hiroyasu and Arai model, the modified spray model is in good agreement with the experimental data and is more suitable for predicting the macroscopic spray characteristics of the blended fuel under high injection pressure.