Transport Processes I: Heat and Mass Transfer

3) Consider the flow of water of 1 point density 103 kg/m3 and viscosity 10 3 kg/m/s in a tube of length 2 m. The average flow velocity is 1 m/s, and the applied pressure difference between the ends is 3.1 kPa. 5 questions are being asked as follows: What is the Reynolds number? 1) For a vertical downward flow of a liquid 1 point in a pipe in absence of any applied pressure gradient, the hydrostatic head provides the pressure gradient. Instead of the pressure gradient term in the momentum equation, the flow is driven by the body force per unit volume, (Pg), where p is the liquid density and g is the gravitational acceleration. If the pipe diameter is d, the average fluid velocity is and the viscosity is p.2 questions are related to this description as follows: 0 102 O 103 0 104 O 10- is friction factor related to the Froude number based on the mean velocity and pipe diameter, (/vgd) 4) What is the friction factor ? 1 point 0.03875 O f = (Fr/2) 0.00775 0.003875 O f = (Fr2/2) 0.00125 Of= (1/(2Fr)) O f= (1/(2F-?)) 5) What is the approximate ratio of the 1 point actual friction factor and the friction factor for a laminar flow at the same Reynolds number 01 1 point O2 2) For Laminar flow, what is the relation between the Froude number and the Reynolds number? 05 Re x Fr 010 Re Fp2 6) What is the friction velocity? 1 point 0.01 Re x Fr.-1 O 0.024 Re Fr-2 O 0.031 O 0.062