MECHANICS OF FLUIDS

MODEL EXAMINATION-I

Time: 3.00hrs Max marks: 100

Dae: 11.10.1! "A#T A - $10 !% !0 marks& De': CI(IL

A)s*er ALL +,esi)s:

1. List the types of fluid flow.

2. Compare Laminar and Turbulent flow.

3. State the assumptions used in deriving Bernoulli’s euation

!. "ention the range of #eynold’s number for laminar and turbulent flow in a pipe.$. %efine &mpulse "omentum 'uation

(. Classifi)ation of boundary layer.

*. %efine momentum thi)+ness.,. '-plain minor losses in a pipe.

. /ive an e-pression for loss of head due to an obstru)tion in pipe

10. %efine the terms a ydrauli) gradient line /L4 b Total 'nergy line T'L4

"A#T $/X1%0&

 A)s*er ALL +,esi)s:

11. 5i 5a %erives 'uler’s 'uation of "otion and proves the Bernoulli’s euation. 511  5b %efine the terms6 i 7inemati)s of flow ii 8niform and non9uniform flows iii

#otational and irrotational flows 5$

Or

  5ii 5a : pipe 300m long has a slope of 1 in100 and tapers from 1m diameter at the high end to

0.$m at the low end . The uantity of water flowing is $!00 m3;min. &f the pressure at the high end

is !033 <;m=> find the pressure at the low end. ?hat is the )hange in pressure if the head loss

 between the two se)tions is 0.!$m of water@ 510  5b ?hat are the appli)ation of Bernoulli’s euation and e-plain the Aenturimeter with neat

s+et)h 5(

12. 5i State the momentum euation. ow will you apply momentum euation for determining the

for)e e-erted by a flowing fluid on a pipe bend@ 51(

Or

  5ii ?hat is the appli)ation of dar)y9weisba)h euation@ %erive an e-pression for the same. 512

 ?hat are the maor and minor losses of flow through pipes@ 5!

 

13. 5i btain the agen Dpoiseuille’s euation for pressure differen)e between two se)tions 1 and2in the pipe is given by

  5p1 Dp2E32FGL;%2 with usual notations. 51(

Or

  5ii5a : plate of (00mm length and !00mm wide is immersed in a fluid of spe)ifi) gravity 0.

and +inemati) vis)osity 109! m=;se). The fluid is moving with a velo)ity of ( m;se). %etermine i

 boundary layer thi)+ness ii shear stress at the end of the plate> and iii drag for)e on one side of the plate. 512H!

  5b %efine %ispla)ement thi)+ness. %erive an e-pression for the %ispla)ement thi)+ness.

1!. 5i Iind the displa)ement> momentum and energy thi)+ness for the velo)ity distribution in the

 boundary layer given by>

  u;8E 25y;J95y;J2   51(

Or

 

  5ii 5a: thin plate is moving in still atmospheri) air at a velo)ity of $m;se). The length of the

 plate is 0.(m and width 0.$m. Cal)ulate i the thi)+ness of the boundary layer at the end of the plate

and ii %rag for)e on one side of the plate. Ta+e density of air as 1.2! +g;m3 and +inemati)vis)osity 0.1$ stro+es. 512

  5b ?hat do you understand by the term Boundary layer and Boundary Layer theory@ 5!

1$. 5i 5a %erive an e-pression for head lost due to sudden )ontra)tion of the pipe. 5(  5b : pipe in)reasing in diameter suddenly from 12)m to 22)m .if the dis)harge of water 

through a pipe is 120lit;se). %etermine the loss of head due to sudden enlargement of )ross se)tion

area. :lso determine the pressure differen)e between two se)tions of pipe line. 510

Or

  5ii The differen)e in water level between two tan+s> whi)h are )onne)ted by three pipes in

series> is 1$m. Lengths and diameters of these pipe are 300m> 1$0m> 200m and 30)m> 20)m> and30)m respe)tively. Iind the dis)harge through the pipe line )onsider 5i :ll losses >5ii <egle)ting

minor losses and tabulate all losses if fri)tion fa)tor for three pipes are ta+en as 0.02> 0.02$ and 0.03

. 51(

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