OCR Text |
Show center of the spray spot to its discharge hole. The spray angle, G * s was half of the angle formed by the furthermost horizontal points of the spray spot and the discharge hole of the injector (Figure 3.) For each spray, the average L and 9 was used. The fuel properties were used to calculate the theoretical mean drop diameter, d (17). The equation for d was derived from m ** m experimental results. Upon manipulation this equation yields d as a function of Re, We, V, and p. The velocity used in the Re and We was an approximation obtained from the energy equation for flow through an orifice plate. The equation reduces to: V = K 2 AP I P (D The value of the discharge coefficient, K, was obtained from literature to be 0.60 for non-tapered orifices (25, 26). The INOP was used as AP. The theoretical spray angle, 0, , was calculated assuming that a theoretical drop forms a circular spot at a distance L from the discharge hole, and that this circular spot has a diameter equal to d . m Thus 0, was defined as the angle formed by the furthermost m *** horizontal points of the spots and its discharge hole. *The furthermost horizontal points were chosen as opposed to the vertical points because the horizontal points were more indicative of the spray than the vertical points which were affected by the injection angle. **Manipulation of the equation for d is in Appendix B. ^•^Development of equation for G, is in Appendix C. m -23- |