Droplet vaporization models that are currently employed in simulating diesel engine sprays are based on a quasi-steady, low-pressure formulation. This formulation does not adequately represent many high-pressure effects, such as non-ideal gas behavior, solubility of gases into liquid, pressure dependence of liquid- and gas-phase thermophysical properties, and transient liquid transport in the droplet interior. More importantly, the quasi-steady assumption becomes increasingly questionable as the ambient pressure approaches and /or exceeds the fuel critical pressure. In the present study, a high-pressure, quasi-steady vaporization model is developed. Except for the quasi-steady assumption that is retained in the model, it incorporates all the other high-pressure effects. The applicability of this model for predicting droplet vaporization under diesel-like environment is evaluated by comparing its predictions with those from a more comprehensive transient model, which is first validated by using the available experimental data. Results indicate a fairly good agreement between the quasi-steady and transient models for pressure upto the fuel critical pressure. At pressures above this value, the quasi-steady model underpredicts the vaporization rate compared to that predicted by the transient model, and the amount of underprediction becomes increasingly more significant at higher pressures. The differences can be attributed to the quasi-steady gas-phase assumption that leads to larger gas film thickness and, therefore, reduced gas-phase heat and mass fluxes at the droplet surface for the quasi-steady model. Another factor contributing to the reduced vaporization rate for the quasi-steady model is the relatively larger droplet heatup time.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Quasi-Steady High-Pressure Droplet Model for Diesel Sprays


    Weitere Titelangaben:

    Sae Technical Papers


    Beteiligte:

    Kongress:

    SAE 2000 World Congress ; 2000



    Erscheinungsdatum :

    2000-03-06




    Medientyp :

    Aufsatz (Konferenz)


    Format :

    Print


    Sprache :

    Englisch


    Schlagwörter :


    Quasi-steady high-pressure droplet model for diesel sprays

    Aggarwal,S.K. / Zhu,G.S. / Reitz,R.D. et al. | Kraftfahrwesen | 2000


    Quasi-Steady High-Pressure Droplet Model for Diesel Sprays

    Aggarwal, S. K. / Zhu, G.-S. / Reitz, R. D. et al. | British Library Conference Proceedings | 2000


    Number-Based Droplet Velocity Distribution in High Pressure Diesel Fuel Sprays

    Li, Xianguo / Bai, Xingyan / Gong, Yunyi et al. | SAE Technical Papers | 1994


    Number-based droplet velocity distribution in high pressure diesel fuel sprays

    Gong,Y. / Li,X. / Peng,Z. et al. | Kraftfahrwesen | 1994


    Injection Pressure Effects Upon Droplet Behavior in Transient Diesel Sprays

    Hung, Calvin C. / Koo, Ja-Ye / Martin, Jay K. | SAE Technical Papers | 1997