Engineering Sciences
GATE XE External Flows PYQs
Build your understanding with focused practice from past exam papers.
Questions 11–20 of 31. Imported answers require independent review unless marked reviewed.
Question 24
Open questionXE-BMCQ1 markNeeds review
For an incompressible boundary layer flow over a flat plate shown in the figure, the momentum thickness is expressed as
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Open questionXE-BMCQ1 markNeeds review
Consider steady incompressible flow over a flat plate, where the dashed line represents the edge of the boundary layer, as shown in the figure. Which one among the following statements is true?
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Open questionXE-BMCQ2 marksNeeds review
Consider steady incompressible flow of a Newtonian fluid over a horizontal flat plate, as shown in the figure. The boundary layer thickness is proportional to
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Open questionXE-BNAT2 marksNeeds review
Water flows around a thin flat plate (0.25 m long, 2 m wide) with a free stream velocity (
) of 1 m/s, as shown in the figure. Consider linear velocity profile
for which the laminar boundary layer thickness is expressed as
. For water, density = 1000 kg/m
and dynamic viscosity = 0.001 kg/m.s. Net drag force (in N, rounded off to two decimal places) acting on the plate, neglecting the end effects, is ______. 
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You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 29
Open questionXE-BMSQ1 markNeeds review
A boundary layer develops due to a two-dimensional steady flow over a horizontal flat plate. Consider a vertical line away from the leading edge which extends from the wall to the edge of the boundary layer. Which of the following quantity/quantities is/are not constant along the vertical line?
and
represent the components of velocity in the direction along the plate and normal to it, respectively and
is taken along the length of the plate while
is the pressure. Neglect body forces.Your answerSelect all correct options. You can choose more than one.
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Open questionXE-BMCQ2 marksNeeds review
A typical boundary layer over a flat plate has a linear velocity profile with zero velocity at the wall and freestream velocity,
, at the outer edge of the boundary layer. What is the ratio of the momentum thickness to the thickness of the boundary layer?Your answerChoose one option.
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Open questionXE-BMSQ2 marksNeeds review
Identify the configuration(s) in which steady two-dimensional internal flow may show boundary layer separation if the flow direction is left to right.
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Open questionXE-BNAT2 marksNeeds review
Consider two-dimensional turbulent flow of air over a horizontal flat plate of length 1 m. Skin friction coefficient at a length
from the leading edge of the plate is obtained as:
where,
is the local Reynolds number.
Find out the drag force per unit width (in N/m
) on the plate if the free stream air velocity is 10 m/s.
Density and dynamic viscosity of air are given as 1.2 kg/m
and
N-s/m
, respectively.
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Open questionXE-BMCQ1 markNeeds review
The form and friction drags together contribute to the total drag when flow of air occurs past any object. Two orientations of a finite flat plate are shown in the figure. In Orientation-1, the plate is placed perpendicular to the flow while in Orientation-2 the plate is placed parallel to the flow. If the velocity (V) of air in both orientations is the same, which one of the following options is TRUE?
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Open questionXE-BMCQ2 marksNeeds review
The incompressible flow of air over a curved surface having possible flow separation is schematically shown in the figure. Two zones P and Q are indicated in the figure. Which one of the following combinations is TRUE for zones P and Q?
(a) Acceleration of flow, (b) Deceleration of flow, (c) Adverse pressure gradient, (d) Favorable pressure gradient, (e) No flow separation (f) Possible flow separation.
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