During aircraft design and certification, in-flight ice accretions are simulated using ice prediction codes. LEWICE, the ice accretion prediction code developed by NASA, employs a time-stepping procedure coupled with a thermodynamic model to calculate the location, size and shape of an ice accretion. LEWICE has been extensively validated for a wide range of icing conditions. However, continuing improvements to LEWICE predictive capabilities require better understandings of 1) the fundamental physics of turbulent flow generated by ice accretion roughness during an icing event and 2) the mechanisms responsible for convective enhancement of real ice accretion roughness. Recent experiments in the Icing Research Tunnel (IRT) at NASA Glenn Research Center have enabled significant insights into the nature of ice accretion roughness spatial and temporal variations. Other recent investigations have employed scans from the IRT to generate scaled test surfaces to investigate convection enhancement and skin friction interactions of flow over the surfaces with real ice roughness. For this investigation, the measurements of ice roughness characteristics, skin friction, and convection heat transfer enhancement are compared directly to predictions calculated using the LEWICE models. Issues associated with the LEWICE model for predicting laminar-to-turbulent transition are also addressed. The comparisons show that while the LEWICE models significantly overestimate equivalent sand-grain roughness heights and the local skin friction, the resulting LEWICE predictions of convection heat transfer generally agree within 25% of the experimental values for surfaces constructed with low thermal conductivity materials. At each step of the LEWICE model, methods to improve the predictions are provided.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    An Assessment of LEWICE Roughness and Convection Enhancement Models


    Weitere Titelangaben:

    Sae Int. J. Adv. and Curr. Prac. in Mobility


    Beteiligte:

    Kongress:

    International Conference on Icing of Aircraft, Engines, and Structures ; 2019



    Erscheinungsdatum :

    2019-06-10


    Format / Umfang :

    12 pages




    Medientyp :

    Aufsatz (Konferenz)


    Format :

    Print


    Sprache :

    Englisch




    Validation Results for LEWICE 3.0

    Wright, William | AIAA | 2005


    Fortified LEWICE with viscous effects

    CEBECI, TUNCER / CHEN, H. / ALEMDAROGLU, N. | AIAA | 1990


    Validation of LEWICE 2.2 Icing Software Code: Comparison With LEWICE 2.0 and Experimental Data

    Ghenai, C. / Kulkarni, S. / Lin, C. X. et al. | British Library Conference Proceedings | 2005


    Validation Results for LEWICE 3.0

    Wright, W. B. / American Institute of Aeronautics and Astronautics | British Library Conference Proceedings | 2005


    Fortified LEWICE with viscous effects

    Cebeci, Tuncer / Chen, H. H. / Alemdaroglu, N. | NTRS | 1991