Influence of surface waviness for laminar flow nacelle applications

H. Medina, J. M. Early, D. Riordan

    Research output: Contribution to journalArticlepeer-review

    3 Citations (Scopus)


    Transition onset over an engine nacelle is inuenced by a large number of factors (for instance, surface roughness, steps, gaps and damage), many of which can be introduced as a result of the manufacturing process. Rivetting processes can lead to the introduction of surface deviations, which can be represented as either a bump or depression wave function. Previous work on the inuence of leading edge roughness has demonstrated that such surface deviations can either promote or delay transition onset. The current work at Queen's University Belfast seeks to conduct a comprehensive investigation into the consequences of a depression-type surface irregularity on the transitional characteristics exhibited by a laminar flow nacelle, with specific attention paid to both the depression amplitude and streamwise location. Intial work has indicated that careful positioning of the streamwise location of the depression relative to the leading edge is critical in the selection of appropriate manufacturing tolerances, as even milliscale depressions, which have no appreciable inuence on the transitional characteristics of the boundary layer, can have a significant affect on the downstream growth of the turbulent boundary layer. There is also some evidence to suggest that small depressions placed close to the leading edge can have a stabilising effect on the laminar boundary layer, leading to a delay in the transitional Reynolds number in a manner similar to that observed for subcritical protrusions.

    Original languageEnglish
    JournalCollection of Technical Papers - AIAA Applied Aerodynamics Conference
    Publication statusPublished - 2009
    Event27th AIAA Applied Aerodynamics Conference, AIAA-2009-4106 - San Antonio, United States
    Duration: 22 Jun 200925 Jun 2009


    • Depression waves
    • Engine nacelle
    • Leading edge
    • Manufacturing process
    • Manufacturing tolerances
    • Streamwise locations
    • Surface irregularities
    • Surface waviness
    • Turbulent boundary layers

    ASJC Scopus subject areas

    • Aerospace Engineering
    • Mechanical Engineering


    Dive into the research topics of 'Influence of surface waviness for laminar flow nacelle applications'. Together they form a unique fingerprint.

    Cite this