| Certain exhaust after-treatment devices used in modern diesel engines need an injector to spray a liquid, including a fuel, into the exhaust stream. For optimum performance, it is desired that the liquid must atomize and vaporize before it enters the device. The spray of an after-treatment injector was simulated in a computational fluid dynamics (CFD) suite, and showed that evaporation increased with increase in the gas flow rate and gas temperature.;The results of the calculations were used to design an experimental setup to study a diesel after-treatment injector. Water was injected into air flowing with a speed of 1.4 m/s and at temperature of 423 K. High speed imaging and phase Doppler anemometry (PDA) were used to identify regions of high particle count. In these regions, diameter decreased with increasing vertical and horizontal distance from the injector. The vertical velocity of the particles was found to increase marginally with increasing vertical distance from the injector tip. |
