Unsteady flows are an inherent part of vehicle aerodynamics, affecting the stability, the comfort and the safety of the vehicle. Unsteadiness arises in some regions due to flow separation, in other Instances it is due to changing boundary conditions such as natural wind gusts, static structures such as buildings or road-side obstacles, or when overtaking other vehicles. To study the effect of flow unsteadiness on the overall vehicle aerodynamics, it is necessary to first mathematically describe the flow fluctuations, and the present manuscript introduces the basic statistical quantities used to due this. The equations of fluid motion are first examined and the important length and time scales of velocity fluctuations are identified. Then the statistical description of velocity fluctuations in amplitude and spectral domain is given. Finally, parameters introduced to capture especially the nature of time-dependent boundary conditions and their effect on vehicles are discussed.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Characterisation of unsteady flows


    Additional title:

    Kennzeichen instationärer Strömungen


    Contributors:


    Publication date :

    2004


    Size :

    26 Seiten, 21 Bilder, 1 Tabelle, 24 Quellen



    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Characterisation of unsteady flows

    Tropea,C. / Tech.Univ.Darmstadt,DE | Automotive engineering | 2004



    Swirl characterisation in steady and unsteady flows with PIV measurements

    Chaillou,C. / Roy,R. / Druault,P. et al. | Automotive engineering | 2005


    Bifurcations In Unsteady Flows

    Chapman, Gary T. / Tobak, Murray | NTRS | 1992


    Simulation of unsteady flows

    Islam,M. / Audi,Ingolstadt,DE | Automotive engineering | 2004