The molar mass transfer rate from a 20 mm diameter naphthalene sphere placed in stagnant air at 85.8 C and atmospheric pressure is 2.5x10^-7 kmol/s. If air starts flowing across the surface of naphthalene with a velocity of 3 m/s, by what factor will the mass transfer rate increase, all other conditions remaining the same? At 85.8 C vapor pressure of naphthalene is 13.3 mbar, the viscosity and density of air are 2.1x10^-5 kg/m.s and 0.974 kg/m³. Assume that bulk concentration of naphthalene in air is negligible.