def calReNoEq1(GaDe, SuVe, CaPaDi, GaVi):
    """ 
    calculate Reynolds number
    args:
        GaDe: gas density [kg/m^3]
        SuVe: superficial velocity [m/s]
        CaPaDi: catalyst particle diameter [m]
        GaVi: gas viscosity [Pa.s]
    """
    # try/except
    try:
        return SuVe*CaPaDi*GaDe/GaVi
    except Exception as e:
        raise