Hydrodynamic And Thermal Boundary Layers MCQs

Welcome to our comprehensive collection of Multiple Choice Questions (MCQs) on Hydrodynamic And Thermal Boundary Layers, a fundamental topic in the field of Heat Transfer. Whether you're preparing for competitive exams, honing your problem-solving skills, or simply looking to enhance your abilities in this field, our Hydrodynamic And Thermal Boundary Layers MCQs are designed to help you grasp the core concepts and excel in solving problems.

In this section, you'll find a wide range of Hydrodynamic And Thermal Boundary Layers mcq questions that explore various aspects of Hydrodynamic And Thermal Boundary Layers problems. Each MCQ is crafted to challenge your understanding of Hydrodynamic And Thermal Boundary Layers principles, enabling you to refine your problem-solving techniques. Whether you're a student aiming to ace Heat Transfer tests, a job seeker preparing for interviews, or someone simply interested in sharpening their skills, our Hydrodynamic And Thermal Boundary Layers MCQs are your pathway to success in mastering this essential Heat Transfer topic.

Note: Each of the following question comes with multiple answer choices. Select the most appropriate option and test your understanding of Hydrodynamic And Thermal Boundary Layers. You can click on an option to test your knowledge before viewing the solution for a MCQ. Happy learning!

So, are you ready to put your Hydrodynamic And Thermal Boundary Layers knowledge to the test? Let's get started with our carefully curated MCQs!

Hydrodynamic And Thermal Boundary Layers MCQs | Page 3 of 5

Discover more Topics under Heat Transfer

Q21.
During test-run, air flows at 215 m/s velocity and 25 degree Celsius temperature past a smooth thin model airfoil which can be idealized as a flat plate. If the chord length of the airfoil is 15 cm, find drag per unit width. The relevant physical properties of air are

p = 1.82 kg/m³
v = 15.53 * 10¯⁶ m²/s

a.

25.42 N per unit width

b.

35.42 N per unit width

c.

45.42 N per unit width

d.

55.42 N per unit width

Discuss
Answer: (a).25.42 N per unit width
Q22.
A flat plate was positioned at zero incidence in a uniform flow stream of air. Assuming boundary layer to be turbulent over the entire plate, workout the ratio of skin-friction forces on the front and rear half part of the plate

a.

1.557

b.

1.447

c.

1.347

d.

1.247

Discuss
Answer: (c).1.347
Q23.
For a particular engine, the underside of the crankcase can be idealized as a flat plate measuring 80 cm by 20 cm. The engine runs at 80 km/hr and the crankcase is cooled by the air flowing past it at the same speed. Find loss of the heat from the crank case surface (t S = 25 degree Celsius). Assume the boundary layer to be turbulent

a.

465.04 W

b.

565.04 W

c.

665.04 W

d.

765.04 W

Discuss
Answer: (b).565.04 W
Q24.
A flat plate 1 m by 1 m is placed in a wind tunnel. The velocity and temperature of free stream air are 80 m/s and 10 degree Celsius. The flow over the whole length of the plate is made turbulent by turbulizing grid placed upstream of the plate. Find the thickness of hydrodynamic boundary layer at trailing edge of the plate

a.

19.55 mm

b.

18.55 mm

c.

17.55 mm

d.

16.55 mm

Discuss
Answer: (d).16.55 mm
Q25.
A flat plate 1 m by 1 m is placed in a wind tunnel. The velocity and temperature of free stream air are 80 m/s and 10 degree Celsius. The flow over the whole length of the plate is made turbulent by turbulizing grid placed upstream of the plate. Find the heat flow from the surface of the plate

a.

9424.5 W

b.

8424.5 W

c.

7424.5 W

d.

6424.5 W

Discuss
Answer: (c).7424.5 W
Q26.
The concept of hydrodynamic boundary layer was first suggested by

a.

Isaac Newton

b.

Ludwig Prandtl

c.

Rodridge

d.

Fourier

Discuss
Answer: (b).Ludwig Prandtl
Q27.
The free stream undisturbed flow has a uniform velocity U INFINITY in the

a.

X-direction

b.

Y-direction

c.

Z-direction

d.

Any direction

Discuss
Answer: (a).X-direction
Q28.
The thin layer where velocity changes continuously is called

a.

Differential layer

b.

Thermal boundary layer

c.

Hydrodynamic boundary layer

d.

Velocity distribution layer

Discuss
Answer: (c).Hydrodynamic boundary layer
Q29.
The conditions for flow beyond the boundary layer and its outer edge are

a.

d u/d y = 0 and u = U 0

b.

d u/d y = Infinity and u = U INFINITY

c.

d u/d y = 1 and u = U 0

d.

d u/d y = 0 and u = U INFINITY

Discuss
Answer: (d).d u/d y = 0 and u = U INFINITY
Q30.
The pattern of flow in the boundary layer is judged by the

a.

Reynolds number

b.

Fourier number

c.

Peclet number

d.

Grashof number

Discuss
Answer: (a).Reynolds number
Page 3 of 5