A two-phase flow mixture of air and silicone (Dow Corning 200® Fluid, 5 cs) is being transported in an 11.7-mmdiameter thin-walled horizontal tube. The liquid phase consists of liquid silicone with surface tension (σ) of 19.7 × 10^-3 N/m, dynamic viscosity (μ_l) of 45.7 × 10^-4 kg/m · s, density (ρ_l) of 913 kg/m³, thermal conductivity (k_l) of 0.117 W/m · K, and Prandtl number (Prl) of 64. The dynamic viscosity of the liquid silicone evaluated at the tube surface temperature (μ_s) is 39.8 × 10^-4 kg/m·s. The gas phase consists of air with dynamic viscosity (mg) of 18.4 × 10^-6 kg/m · s, density (ρ_g) of 1.19 kg/m³, and Prandtl number (Pr_g) of 0.71.The two-phase flow has flow quality (x) of 2.08 × 10^-5, void fraction (α) of 0.011, gas velocity (V_g) of 13.5 m/s, liquid velocity (V_l) of 9.34 m/s, and liquid mass flow rate (ṁ_l) of 0.907 kg/s. Moist air at a saturation temperature of 40°C condenses on the outer surface of the tube. The tube has a uniform surface temperature of 20°C. Determine the overall convection heat transfer coefficient (inside and outside) of the tube.

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Air-silicone mixture Moist air, 40°C 20°C