def calSpaceVelocity(VoFlRa, ReVo):
    """
        cal: space velocity [1/s]

        args:
            VoFlRa: volumetric flowrate [m^3/s]
            ReVo: reactor volume [m^3]

    """
    # try/except
    try:
        SpVe = VoFlRa/ReVo
        # res
        return SpVe
    except Exception as e:
        print(e)