### Air is injected into a vertical (upward) water flow in a pipe with diameter of ( 150 mathrm{~mm} ). The water flow rate is 180 lit/s and the air flow rate is 55 lit/s. Properties of air and water are: [ begin{array}{l} rho_{text {air }}=1.2 mathrm{~kg} / mathrm{m}^{2} \ mu_{text {air }}=1.9 times 10^{-5} mathrm{Pa.s} \ rho_{text {water

Air is injected into a vertical (upward) water flow in a pipe with diameter of ( 150 mathrm{~mm} ). The water flow rate is 180 lit/s and the air flow rate is 55 lit/s. Properties of air and water are: [ begin{array}{l} rho_{text {air }}=1.2 mathrm{~kg} / mathrm{m}^{2} \ mu_{text {air }}=1.9 times 10^{-5} mathrm{Pa.s} \ rho_{text {water