Combined experimental and numerical study on fuel deposition characteristics of an impinging PFI spray with different impingement geometries

Abstract

This paper presents a combined experimental and numerical study on the fuel deposition characteristics during the Port fuel injection (PFI) spray impingement process. The numerical models mainly consisted of a newly developed atomization model, the Senda spray impingement model, and the Bai-Gosman liquid film model. A group of measurement methods were used to hierarchically calibrate and validate the numerical models. It was found that the calibrated models were able to predict the time-resolved morphology of the impinging spray, as well as the shape, area, and thickness distribution of the deposited fuel film with a good reliability. Then the calibrated models were used to study the effects of impingement distance (L_w) and impingement angle (θ_w) on the fuel film deposition. The results showed that as L_w increases, the film area (A_f) and film mass (m_f) rise faster and reach higher final values. As θ_w increases, A_f and m_f grow slower, and their final values are hugely reduced. Increasing L_w and decreasing θ_w can effectively reduce the average film thickness (h_f,a). A_f is mainly affected by the contact area between the spray plumes and the impinging wall, while m_f is also affected by the dominant droplet-wall interaction regime.