Heat Transfer Questions and Answers – Von- Karmal Equation

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This set of Heat Transfer Multiple Choice Questions & Answers (MCQs) focuses on “Von- Karmal Equation”.

1. Glycerin at 10 degree Celsius flows past a flat plate at 20 m/s. Workout the velocity components at a point P(x, y) in the fluid flow where
x = 2 m from the leading edge of the plate
y = 5 cm from the plate surface
For glycerin at 10 degree Celsius, kinematic viscosity = 2.79 * 10 -3 m2/s
a) 15.92 m/s and 0.0952 m/s
b) 16.92 m/s and 0.0952 m/s
c) 17.92 m/s and 0.0752 m/s
d) 18.92 m/s and 0.0752 m/s
View Answer

Answer: b
Explanation: u/U INFINITY = 0L.846 and v/U INFINITY (Re) ½ = 0.57.
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2. A plate 0.3 m long is placed at zero angle of incidence in a stream of 15 degree Celsius water moving at 1 m/s. Find out the stream wise velocity component at the mid-point of the boundary layer. For water at 15 degree Celsius
p = 998.9 kg /m3
µ = 415.85 * 10 -2 kg/hr m
a) 0.736 m/s
b) 0.636 m/s
c) 0.536 m/s
d) 0.436 m/s
View Answer

Answer: a
Explanation: n = y (U INFINITY/v x) ½ = 2.5.

3. Air at 25 degree Celsius flows over a flat surface with a sharp leading edge at 1.5 m/s. Find the boundary layer thickness at 0.5 from the leading edge. For air at 25 degree Celsius, kinematic viscosity = 15.53* 10n -6 m2/s
a) 4.1376 cm
b) 3.1376 cm
c) 2.1376 cm
d) 1.1376 cm
View Answer

Answer: d
Explanation: δ = 5 x/ (Re) ½ = 1.1376 m.

4. Local skin friction coefficient is given by
a) 0.646/ (Re) 1/2
b) 1.646/ (Re) 1/2
c) 2.646/ (Re) 1/2
d) 3.646/ (Re) 1/2
View Answer

Answer: a
Explanation: It should be 0.646/ (Re) ½.
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5. A plate 0.3 m long is placed at zero angle of incidence in a stream of 15 degree Celsius water moving at 1 m/s. Find out the maximum boundary layer thickness. For water at 15 degree Celsius. For water at 15 degree Celsius
p = 998.9 kg /m3
µ = 415.85 * 10 -2 kg/hr m
a) 4.945 m
b) 3.945 m
c) 2.945 m
d) 1.945 m
View Answer

Answer: c
Explanation: Re = l p U INFINITY/µ.

6. Shear stress at the middle of the plate is given by
a) T W = 0.964 p U INFINITY 2/2 (Re) 1/2
b) T W = 0.864 p U INFINITY 2/2 (Re) 1/2
c) T W = 0.764 p U INFINITY 2/2 (Re) 1/2
d) T W = 0.664 p U INFINITY 2/2 (Re) 1/2.
View Answer

Answer: d
Explanation: T W = 3 µ U INFINITY/2 δ = 0.664 p U INFINITY 2/2 (Re) ½.

7. Boundary layer thickness is given by
a) δ = 5.64 x/ (Re) ½
b) δ = 5.64 x/ (Re) ½
c) δ = 6.64 x/ (Re) ½
d) δ = 7.74 x/ (Re) ½
View Answer

Answer: a
Explanation: δ/x = (140 * 2/13) ½ (µ/x p U INFINITY) ½.
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8. Air at 25 degree Celsius flows over a flat surface with a sharp leading edge at 1.5 m/s. Find the value of Reynolds number. For air at 25 degree Celsius, kinematic viscosity = 15.53* 10n -6 m2/s
a) 38694
b) 12846
c) 48294
d) 76386
View Answer

Answer: c
Explanation: Re = x U INFINITY/v = 48294.

9. A plate 0.3 m long is placed at zero angle of incidence in a stream of 15 degree Celsius water moving at 1 m/s. Find out the maximum value of the normal component of velocity at thr trailing edge of the plate. For water at 15 degree Celsius
p = 998.9 kg /m3
µ = 415.85 * 10 -2 kg/hr m
a) 1.6885 * 10 -2 m/s
b) 1.6885 * 10 -3 m/s
c) 1.6885 * 10 -4 m/s
d) 1.6885 * 10 -5 m/s
View Answer

Answer: b
Explanation: v/U INFINITY (Re) ½ =0.860.

Sanfoundry Global Education & Learning Series – Heat Transfer.

To practice all areas of Heat Transfer, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer & SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage, Advanced C Programming, SAN Storage Technologies, SCSI Internals & Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him @ LinkedIn