(1) Describe briefly the definition of fully developed laminar
flow.
(2) From governing laws for fully developed laminar flow, derive
an equation for fully developed laminar flow that shows the
relation between flowrate and pressure gradient.
Convection Heat transfer internal flow
Consider water flowing in a heated tube. The tube is 14 m long
with an inner diameter of 1 cm. The heat
is added at 1500 W/m2 uniformly along the tube. Water flows at 0.3
m/s. Use the following water property
? = 1000 kg/m3, ? = 1.4 × 10?3 kg/m·s, cp =
4.2 kJ/kg·K, k = 0.58 W/m·K, and determine
1. Heat transfer coefficient at the tube exit.
2. Tube surface temperature at the...
Concept 1: Does turbulent flow or laminar flow have a greater
heat transfer coefficient? Why?
Concept 2: For flow over a flat plate, why does the heat
transfer coefficient decrease the greater the distance from the
leading edge? (in answering, ignore the effects of flow regime
transitions. i.e. assume the flow over the plate is all laminar or
all turbulent).
Fully developed (both hydrodynamic and thermal) laminar flow is
pushed through a thin-walled circular pipe of diameter 13 mm. The
fluid flows through the pipe at a velocity of 0.1 m/sec, has a
density of 1000 kg/m^3, a dynamic viscosity of 855 x 10^-6 Pa-sec,
a specific heat of 4000 J/kg-K, a Prandtl number of 8, and a
thermal conductivity of 0.613 W/(m-K).
The outside of the pipe is subjected to uniform cross flow where
the free-stream velocity is 5...
A steady two-dimensional laminar fully-developed flow downward
between
two fixed parallel plates inclined at 50" with horizontal is
shown in figure. The
pressure gradient in the direction of the flow is -3935 N/m' per
m. Note the
space between parallel plates is 5mm.Use the Navier-Stokes
equation in the
flow direction to determine:
a-Velocity distribution of the flow between two plates.
b-Shear stress distribution of the low between two plates.
c- The average velocity of the flow
d- Maxinmum velocity
e-Mininmum...
Heat transfer
In a test in a double tube heat exchanger the following data are
obtained
For hot fluid
Flow = 11.6 gal / sec
Outlet temperature = 30.1 ° C
Inlet temperature = 32 ° C
For cold fluid
Flow 11gal / min
Outlet temperature 25.1 ° C
Inlet temperature 24.2 ° C
For the fluid consider
k = 0.49 w / mK
cp = 3729.95 J / kgK
Prandtl number = 14.29
Density = 1035.02kg / m3
Get:...
Heat transfer
in a test in a double tube heat exchanger the following data are
obtained
For hot fluid
Flow = 11.6 gal / sec
Outlet temperature = 30.1 ° C
Inlet temperature = 32 ° C
For cold fluid
Flow 11gal / min
Outlet temperature 25.1 ° C
Inlet temperature 24.2 ° C
For the fluid consider
k = 0.49 w / mK
cp = 3729.95 J / kgK
Prandtl number = 14.29
Density = 1035.02kg / m3
Get:...
Consider the transient heat transfer of a solid object suddenly
exposed to an unbounded flow at different temperature. Based on the
Lumped-heat capacity model (LHCM), the response time of heat
transfer to the solid can be used to determine the convective heat
transfer coefficient. Assume that the solid initial temperature,
the ambient fluid temperature, and a temperature at the center of
solid at a given time (after the exposure) are measurable. (1)
Ignoring the radiation, derive an equation to correlate...