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Internal Flow
Jigsaw
Developed by Dr. Don
Richards, Rose-Hulman Institute of Technology
Internal Flow
Jigsaw Questions
Assignment
for Period 24 (Friday, 18 April 2003)
Explanation
of this assignment:
One way to reduce the work that all of us have to do to
learn new material is to divide up the material, each of us
become an “expert” on a small area, and then share what
we’ve learned with others. This active learning technique is
commonly referred to as a Jigsaw because like a
jigsaw puzzle each of us contributes a small piece of
knowledge that helps everyone understand the big picture. To
get the most benefit with the least amount of effort follow
the instructions below carefully. You can obviously do more,
but each of you must do the minimum so that we all get the
benefit of this tool.
[This
entire assignment should take no longer than 30 to 45
minutes]
1.
Review/skim the material in Sections 8.1-8.4 for pertinent
material on your assigned flow regime. Read Section 8.5
(Laminar Flow) or Section 8.6 (Turbulent Flow) as
assigned.
2. Prepare
answers to the following on your assigned flow regime.
Unless indicated otherwise all questions are
for steady flow in a smooth circular pipe. Read “XXXX” as
either laminar or turbulent.
How do you decide if a flow is XXXX?
Sketch the velocity at a single point in the
XXXX flow as a function of time?
How long is the hydrodynamic entrance
length, i.e. Lh /D, in XXXX
flow?
How long is the thermal entrance length,
i.e. Lt /D, in XXXX flow?
What is the friction factor f (Darcy
friction factor) for fully-developed XXXX flow?
How can you find a value for it?
How does the Darcy friction factor for
fully-developed XXXX flow given here relate to the
values in the Moody friction factor chart?
What is the Nusselt number for
fully-developed, XXXX flow with constant surface heat
flux ( = constant) boundary condition?
What is the Nusselt number for
fully-developed, XXXX flow with constant surface
temperature (Ts=constant; isothermal
wall) boundary condition?
What is the impact of surface roughness on
friction faction and Nusselt number for fully-developed
XXXX flow?
How do you predict friction factor and
Nusselt number for fully-developed XXXX flow
in tubes or ducts with non-circular cross sections?
Internal Forced
Convection in a Duct |
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Laminar Flow |
Turbulent Flow |
How
do you decide if an internal flow is laminar or
turbulent? |
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Sketch the velocity at a single point in a
laminar/turbulent flow as a function of time?
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How
long is the hydrodynamic entrance length measured
in diameters, i.e. Lh /D, in
laminar/turbulent flow? What is its maximum value? |
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How
long is the thermal entrance length measured in
diameters, i.e. Lt /D, in
laminar/turbulent flow? What is its maximum value? |
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What
is the friction factor f (Darcy friction factor)
for fully-developed laminar/turbulent
flow? How can you find a value for it? |
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How
does the friction factor f (Darcy friction
factor) for fully-developed laminar/turbulent flow
given here relate to the values in the Moody friction
factor chart? |
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In
external flow, fluid properties are usually evaluated at
the film temperature Tfilm. In
an internal flow, what temperature is used to evaluate
the fluid properties? |
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What
is the Nusselt number for fully-developed
laminar/turbulent flow with constant
surface heat flux (= constant) boundary condition? Assume
a normal range of Prandtl number. |
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What
is the Nusselt number for fully-developed,
laminar/turbulent flow with constant surface
temperature (Ts=constant;
isothermal wall) boundary condition? Assume a
normal range of Prandtl number. |
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What
is the impact of surface roughness on friction faction
and Nusselt number for fully-developed
laminar/turbulent flow? |
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How
do you predict friction factor and Nusselt number for
fully-developed laminar/turbulent flow in
tubes or ducts with non-circular cross sections? |
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How
do you predict Nusselt number for developing
laminar/turbulent flow in tubes or ducts with
circular cross-sections, i.e for flow in the entrance
region? |
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Instruction
to Students
©2003,Don Richards
These materials may be duplicated for educational purposes
if properly credited. |
