Regular formulae for lateral aerodynamic force cannot give precise prediction under unsteady crosswind. By generalizing potential flow theory and taking the aerodynamic derivative into consideration, the semi-empirical expression for lateral aerodynamic force is derived. In order to determine the coefficients in the semi-empirical formula, the model of a typical double-deck coach is investigated in a sequence of numerical simulations under pure crosswind condition (i.e. linear crosswind, pseudo-step crosswind, sinusoidal crosswind). Moreover, advantages of the semi-empirical formula over the regular one are revealed. Further inspections into the flow field derived from the theory of vortex motion indicate that the deviation between the prediction given by semi-empirical formulae and that by numerical simulation is caused by the non-viscous assumption in potential flow theory. The lateral aerodynamic force depends linearly on the crosswind aerodynamic derivative. Situations in which the coach is moving in the direction perpendicular to the wind velocity are also studied to find the cause of the error in semi-empirical formula. Furthermore, the semi-empirical formula is revised by introducing the “damping model method”. A relatively complete system of prediction for lateral aerodynamic force on a coach, which is of practical engineering significance, has been constructed.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Study on the Aerodynamics Mechanism of Passenger Car under Unsteady Crosswind


    Contributors:
    Shen, Chen (author) / Zhu, Hui (author) / Yang, Zhi-Gang (author)


    Publication date :

    2013


    Size :

    8 Seiten




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English







    Large-Eddy Simulation for vehicle aerodynamics in unsteady crosswind condition

    Nakashima, T. / Tsubokura, M. / Kitoh, K. et al. | British Library Conference Proceedings | 2009


    Detached-Eddy Simulations Applied to Unsteady Crosswind Aerodynamics of Ground Vehicles

    Favre, T. / Diedrichs, B. / Efraimsson, G. | Tema Archive | 2010