PROBLEM 1.62
KNOWN: Elapsed times corresponding to a temperature change from 15 to 14C for a reference
sphere and test sphere of unknown composition suddenly immersed in a stirred water-ice mixture.
Mass and specific heat of reference sphere.
FIND: Specif
PROBLEM 2.1
KNOWN: Steady-state, one-dimensional heat conduction through an axisymmetric shape.
FIND: Sketch temperature distribution and explain shape of curve.
SCHEMATIC:
ASSUMPTIONS: (1) Steady-state, one-dimensional conduction, (2) Constant properties
PROBLEM 2.2
KNOWN: Axisymmetric object with varying cross-sectional area and different temperatures at
its two ends, insulated on its sides.
FIND: Shapes of heat flux distribution and temperature distribution.
SCHEMATIC:
T1
T2
T1 > T2
dx
x
L
ASSUMPTIONS:
PROBLEM 2.3
KNOWN: Hot water pipe covered with thick layer of insulation.
FIND: Sketch temperature distribution and give brief explanation to justify shape.
SCHEMATIC:
ASSUMPTIONS: (1) Steady-state conditions, (2) One-dimensional (radial) conduction, (3)
PROBLEM 2.4
KNOWN: A spherical shell with prescribed geometry and surface temperatures.
FIND: Sketch temperature distribution and explain shape of the curve.
SCHEMATIC:
ASSUMPTIONS: (1) Steady-state conditions, (2) One-dimensional conduction in radial (sp
PROBLEM 2.5
KNOWN: Symmetric shape with prescribed variation in cross-sectional area, temperature
distribution and heat rate.
FIND: Expression for the thermal conductivity, k.
SCHEMATIC:
ASSUMPTIONS: (1) Steady-state conditions, (2) One-dimensional conduc
PROBLEM 2.6
KNOWN: Rod consisting of two materials with same lengths. Ratio of thermal conductivities.
FIND: Sketch temperature and heat flux distributions.
SCHEMATIC:
T1
T2
T1 < T2
A
x
0.5 L
B
L
ASSUMPTIONS: (1) Steady-state conditions, (2) One-dimension
PROBLEM 2.7
KNOWN: End-face temperatures and temperature dependence of k for a truncated cone.
FIND: Variation with axial distance along the cone of q x , q , k, and dT / dx.
x
SCHEMATIC:
r
ASSUMPTIONS: (1) One-dimensional conduction in x (negligible temp
PROBLEM 2.9
KNOWN: Irradiation and absorptivity of aluminum, glass and aerogel.
FIND: Ability of the protective barrier to withstand the irradiation in terms of the temperature
gradients that develop in response to the irradiation.
SCHEMATIC:
G = 10 x 106
PROBLEM 2.12
KNOWN: Plane wall with prescribed thermal conductivity, thickness, and surface temperatures.
FIND: Heat flux, q , and temperature gradient, dT/dx, for the three different coordinate systems
x
shown.
SCHEMATIC:
ASSUMPTIONS: (1) One-dimensional
DESIGN PROJECT
Design Project will be conducted in team, organized by a team leader and conducted with close
communications within the team and with instructor & TA. Each team will select a system/assembly and
related processes and each member of the team
The materials that facemasks are made of are: titanium, stainless steel, and carbon steel. Each
facemask is coated with a powder coating called Polyarmor G17 which is resistant to impact
and corrosion. Football facemask are used protect the players face w
PROBLEM 1.7
KNOWN: Inner and outer surface temperatures of a glass window of prescribed dimensions.
FIND: Heat loss through window.
SCHEMATIC:
ASSUMPTIONS: (1) One-dimensional conduction in the x-direction, (2) Steady-state
conditions, (3) Constant proper
PROBLEM 1.20
KNOWN: Inner and outer surface temperatures of a wall. Inner and outer air temperatures and
convection heat transfer coefficients.
FIND: Heat flux from inner air to wall. Heat flux from wall to outer air. Heat flux from wall to
inner air. Whe
ME 4150, Fall 2013
HW #2 (due on 09/25/13)
Use material properties from Table A-5 to solve following problems.
1. Sketch a free-body diagram of each element in the figure. Compute the magnitude and
direction of each force using an algebraic or vector meth
ME 4210-HEAT TRANSFER LABORATORY #1
Free and Forced Convection Experiments
I. Objectives
To review the following convection heat transfer concepts, practice related measurements and
data analyses, and compare measured results against predictions:
1. Funda
PROBLEM 1.1
KNOWN: Thermal conductivity, thickness and temperature difference across a sheet of rigid
extruded insulation.
FIND: (a) The heat flux through a 2 m 2 m sheet of the insulation, and (b) The heat rate
through the sheet.
SCHEMATIC:
A = 4 m2
k =
PROBLEM 1.2
KNOWN: Thickness and thermal conductivity of a wall. Heat flux applied to one face and
temperatures of both surfaces.
FIND: Whether steady-state conditions exist.
SCHEMATIC:
L = 10 mm
T2 = 30C
q = 20 W/m2
T1 = 50C
qcond
k = 12 W/mK
ASSUMPTIONS
PROBLEM 1.3
KNOWN: Inner surface temperature and thermal conductivity of a concrete wall.
FIND: Heat loss by conduction through the wall as a function of outer surface temperatures ranging from
-15 to 38C.
SCHEMATIC:
ASSUMPTIONS: (1) One-dimensional condu
PROBLEM 1.4
KNOWN: Dimensions, thermal conductivity and surface temperatures of a concrete slab. Efficiency
of gas furnace and cost of natural gas.
FIND: Daily cost of heat loss.
SCHEMATIC:
ASSUMPTIONS: (1) Steady state, (2) One-dimensional conduction, (3
PROBLEM 1.6
KNOWN: Heat flux and surface temperatures associated with a wood slab of prescribed
thickness.
FIND: Thermal conductivity, k, of the wood.
SCHEMATIC:
ASSUMPTIONS: (1) One-dimensional conduction in the x-direction, (2) Steady-state
conditions,
PROBLEM 1.8
KNOWN: Net power output, average compressor and turbine temperatures, shaft dimensions and
thermal conductivity.
FIND: (a) Comparison of the conduction rate through the shaft to the predicted net power output of
the device, (b) Plot of the rat
PROBLEM 1.9
KNOWN: Width, height, thickness and thermal conductivity of a single pane window and
the air space of a double pane window. Representative winter surface temperatures of single
pane and air space.
FIND: Heat loss through single and double pane
PROBLEM 1.11
KNOWN: Heat flux at one face and air temperature and convection coefficient at other face of plane
wall. Temperature of surface exposed to convection.
FIND: If steady-state conditions exist. If not, whether the temperature is increasing or de
Executive Summary
In the course of engaging in various sports around the world, there are various risks that usually
face the players. For this reason, the given players need to be effectively protected from the
dangers and risks that can potentially affe