GATE Questions & Answers of Flow Through Pipes, Head Losses in Pipes, Bends and Fittings

What is the Weightage of Flow Through Pipes, Head Losses in Pipes, Bends and Fittings in GATE Exam?

Total 12 Questions have been asked from Flow Through Pipes, Head Losses in Pipes, Bends and Fittings topic of Fluid Mechanics subject in previous GATE papers. Average marks 1.50.

Air flows at the rate of 1.5 m3/s through a horizontal pipe with a gradually reducing crosssection as shown in the figure. The two cross-sections of the pipe have diameters of 400 mm and 200 mm. Take the air density as 1.2 kg/m3 and assume inviscid incompressible flow. The change in pressure $ \left(p_2-p_1\right) $ (in kPa) between sections 1 and 2 is

 

For steady flow of a viscos incompressible fluid through a circular pipe of constant diameter, the averavge velocity in the fully developed region is constant. Which one of the following statements about the average velocity in the developing region is TRUE?

Consider steady flow of an incomressible fluid through two long and straight pipes of diameters $ d_1 $ and $ d_2 $ arranged in series. Both pipes are of equal length and the flow is turbulent in both pipes. The friction factor for turbulent flow though pipes is of the form, $ f=K(Re)^{-n} $, where $ K $ and $ n $ are known positive constants and Re is the Reynolds number. Neglecting minir losses, the ratio of the frictional pressure drop in pipe 1 to that  in pipe 2, $\style{font-family:'Times New Roman'}{\left(\frac{\triangle P_1}{\triangle P_2}\right)}$, is given by

The arrangement shown in the figure measures the velocity V of a gas of density 1 kg/m2 flowing through a pipe. The acceleration due to gravity is 9.81 m/s2. If the manometric fluid is water (density 1000 kg/m3) and the velocity V is 20 m/s, the differential head h (in mm) between the two arms of the manometer is__________

 

A 60 mm-diameter water jet strikes a plate containing a hole of 40 mm diameter as shown in the figure. Part of the jet passes through the hole horizontally, and the remaining is deflected vertically. The density of water is 1000 kg/m3. If velocities are as indicates in the figure, the magnitude of horizontal force (in N) required to hold the plate is_______ 

 

A channel of width 450 mm branches into two sub-channels having width 300 mm and 200 mm as shown in figure. If the volumetric flow rate (taking unit depth) of an incompressible flow through the main channel is $ 0.9\;\mathrm m^3/\mathrm s $ and the velocity in the sub-channel of width 200 mm is 3 m/s, the velocity in the sub-channel of width 300 mm is _____________ m/s.
 
Assume both inlet and outlet to be at the same elevation.
 

 

Consider fully developed flow in a circular pipe with negligible entrance length effects. Assuming the mass flow rate , density and friction factor to be constant, if the length of the pipe is doubled and the diameter is halved, the head loss due to friction will increase by a factor of

Three parallel pipes connected at the two ends have flow-rates Q1, Q2 and Q3 respectively, and the corresponding frictional head losses are hL1, hL2 and hL3 respectively. The correct expressions for total flow rate (Q) and frictional head loss across the two ends (hL) are

For a fully developed flow of water in a pipe having diameter 10 cm, velocity 0.1 m/s and kinematic viscosity 10−5 m2/s, the value of Darcy friction factor is _______

For steady, fully developed flow inside a straight pipe of diameter D, neglecting gravity effects, the pressure drop  Δp over a length L and the wall shear stress τ ω are related by

Oil flows through a 200 mm diameter horizontal cast iron pipe (friction factor, f=0.0225) of length 500 m. The volumetric flow rate is 0.2 m3/s. The head loss (in m) due to friction is (assume g = 9.81 m/s2)

Water at 25 °C is flowing through a 1.0 km long G.I pipe of 200 mm diameter at the rate of 0.07 m3/s. If value of Darcy friction factor for this pipe is 0.02 and density of water is 1000 kg/m3, the pumping power (in kW) required to maintain the flow is