(Solved):   Air at \( 110 \mathrm{kPa} \) and \( 50^{\circ} \mathrm{C} \) flows upward through a \( 60 ...

 

Air at \( 110 \mathrm{kPa} \) and \( 50^{\circ} \mathrm{C} \) flows upward through a \( 60 \mathrm{~mm} \)-diameter inclined duct at a rate of \( 45 \mathrm{l} / \mathrm{s} \) (Figure 1). The duct diameter is then reduced to \( 40 \mathrm{~mm} \). The pressure change across the reducer is measured by a water manometer. The elevation difference between the two points on the pipe where the two arms of the manometer are attached is \( 0.2 \mathrm{~m} \). The density of water is \( \rho_{\text {water }}= \) \( 1000 \mathrm{~kg} / \mathrm{m}^{3} \), the density of air is \( \rho_{\text {air }}=1.19 \mathrm{~kg} / \mathrm{m}^{3} \). a) Determine the pressure difference between points 1 and 2 . (6 marks) b) Determine the differential height \( h \) between the fluid levels of the two arms of the manometer. (6 marks) Figure 1