Drag model for gas-liquid system of Tomiyama et al.

Reference:
    "Drag coefficients of single bubbles under normal and microgravity
     conditions"
    Tomiyama, A., Kataoka, I., Zun, I., Sakaguchi, T.
    JSME International Series B, Fluids and Thermal Engineering,
    Vol. 41, 1998, pp. 472-479

Provided by Alberto Passalacq