OCR Text |
Show Injection Properties The injection volumes per 1000 strokes in 0.95 minutes were approximately the same for all fuels tested (Table 4) when the rail pressure was 120 psig, so viscosity did not affect the volume injected. Since the HHV, density, and volume injected were approximately the same, the energy content per injection was not changed appreciably. The significant parameters for DF2 are reported in Table 5. It was determined that it was not possible to obtain one INOP that r e would yield equivalent atomization parameters for the test fuels. Therefore, a coefficient,£ , that incorporated the parameters was developed by the author and used to obtain INOP for the test fuels. e The spray pattern curves obtained by varying the INOP are for a given fuel, plots of c as a function of INOP with a computer-applied fourth order least squares fit (Figures 5-10). Figure 5 is the curve for DF2; the degree and type fit were obtained by trial and error for a variety of curves and degrees. It was observed that the fourth order least squares fit more closely represented the data. The corresponding equivalent coefficient for INOP=2750 psig for DF2 obtained from the spray pattern curve was 15.4. For 10% Dioxalane, the range of INOP was not large enough to indicate the minimum, but INOP was obtained from the curve to be 2825 psig. The minimum was not obtained for 10% MEK either, while the INOP was 2720 psig. This pressure was so close to the manufacturer's specification for INOP (2750 psig) that it could not be justifiably set. Curves for 25% SFO and 10% Dioxalane/5% SFO did not reach either a maximum or a minimum. The INOP for 25% SFO was 3230 psig, and 2650 psig for 10% Dioxalane/5% SFO. The curve for 10% MEK/15% SFO obtained both a maximum and a minimum, while the INOP was 3190 psig. A summary of the INOP 's for the test fuels is shown in Table 6. e -31- |