The planar laser induced exciplex fluorescence(PLIEF)technique was used to quantitatively study the fuel distribution of diesel spray flat wall impingements in a constant volume combustion vessel. In the experiment, the impinging distance was changed from 12.5 mm to 32.5 mm. It is found that the impinging distance have an important impact on the fuel distribution. With an increase in impinging distance, the mass fraction of liquid phase fuel increases, while the mass fraction of vapor phase fuel decreases in the excessively rich mixture area of φ>2. In the richer mixture area of 1<φ≤2, the mass fraction of vapor phase fuel still increases with the increase of impinging distance until to a certain value and then keep unchanged. In the lean mixture area of 0<φ≤1, it still gradually increase with the increases of the impinging distance. In addition, the transient maximum equivalent ratio(φmax)decreases and the transient minimum temperature(Tmin)increases. The wall jet radius and height of the vapor-liquid phase spray decreases, or even does not impinge on the wall. © 2019, Editorial Office of the Transaction of CSICE. All right reserved.
