4.1.2 RME25 with PE
Even though there is a big reduction on the viscosity of the mixtures in comparison with the one of base oil itself, there is no difference on all items, i.e. the ignition delay, the maximum pressure, and the time to Pmax. But, the precision index is rather slightly larger than that of base oil, which means the mixtures are less stable conditions during combustion.
4.2 Mixture with PP
4.2.1 DMA with PP
Regarding the ignition delay of the mixture of DMA and PP, it shows a remarkable change, approximately 20 percent shorter at 5 percent mixture with PP, then approx. 17 percent shorter at other mixing ratio. On the other hand, there are no significant differences between the base oil and the mixtures on the maximum pressure and the time to Pmax.
4.2.2 RME25 with PP
Those mixtures did not show any affection on the three items, i.e. the ignition delay, the maximum pressure, and the time to Pmax., even though the viscosity showed the great changes, i.e. significant reductions, which means the less heating temperature of fuel required before injection. Regarding the precision index, there is no remarkable difference except for at the time to Pmax.
4.3 Ignition Delay and Ratio of LWP
The relationships between the ignition delay of the mixtures and the ratio of LWP are shown in Figure 2 and Figure 3, respectively. Regarding the DMA class fuel oils, only 5 percent addition of LWP into base oil made the ignition delay change, but it seems that the magnitude of the change does not depend on the volume (5-20 %) of LWP, in other word, the LWP makes the ignition delay change comparing to that of base oil, but the affection of the ratio of LWP is small.
Fig. 2 Ignition Delay vs. Ratio of LWP
Fig. 3 Ignition Delay vs. Ratio of LWP
