ME 315
Final Exam
Friday, May 3, 2013
This is a closed-book, closed-notes examination. There is a formula sheet
provided at the end of this exam.
You must turn off all communications devices before starting this exam, and
leave them off for the entire e
ME 315
Exam 2
8:00 -9:00 PM
Tuesday, March 10, 2009
This is a closed-book, closed-notes examination. There is a formula sheet at the
back.
You must turn off all communications devices before starting this exam, and
leave them off for the entire exam.
P
Kevin Lohr
Div 17
9/11/2015
ME 315 Laboratory
Summary Report
Experiment 1
Combined Radiation and Free Convection
Kevin Lohr
Div 17
9/11/2015
Introduction
The objective of this experiment was to measure the effects of radiation and free convection on
both
PROBLEM 14.1
KNOWN: Mixture of O2 and N2 with partial pressures in the ratio 0.21 to 0.79. FIND: Mass fraction of each species in the mixture. SCHEMATIC:
pO2 p N2
MO M
=
0.21 0.79
2
= 32 kg/kmol
N2 = 28 kg/kmol
ASSUMPTIONS: (1) Perfect gas behavior. ANALY
ME315 F2015 Quiz # 8 10/30/2015
Number:
Name:
Signature:
Background:
Consider a boundary layer problem. Clean air of temperature T and velocity U flows over a flat plate
wetted by a thin layer of chemical liquid. The plate is heated and kept at a uniform
ME315 F2015 Quiz # 5 09/25/2015
Number:
Name:
Signature:
True or false:
When we solve a steady-state fin heat transfer problem:
(T) The 1D fin heat transfer equation does NOT give the EXACT solution.
(T) The infinitely long fins have zero fin efficiency.
ME315 F2015 Quiz # 3 09/09/2015
Number:
Name:
Signature:
True or false:
When we solve a heat diffusion equation,
(T) Boundary conditions are always needed to solve a heat diffusion equation
(F) Initial condition is always needed to solve a heat diffusion
PROBLEM 3.90
KNOWN: Geometry and boundary conditions of a nuclear fuel element.
FIND: (a) Expression for the temperature distribution in the fuel, (b) Form of temperature
distribution for the entire system.
SCHEMATIC:
ASSUMPTIONS: (1) One-dimensional heat
ME315 F2015 Quiz # 1 08/28/2015
Number:
Name:
Signature:
True or false:
( F ) Heat diffuses along the direction of the temperature increases
( F ) A higher temperature object contains more thermal energy than the lower temperature ones
( F ) Heat cannot b
ME315 F2015 Quiz # 7 10/22/2015
Number:
Name:
Signature:
Draw the Curves
For the isothermal flat plate being heated by a freestream (i.e., Ts < T), sketch the thermal boundary
layer thickness as a function of x from 0 to L, and carefully draw the temperat
ME315 F2015 Quiz # 9 11/04/2015
Number:
Name:
Signature:
Consider an internal flow through a pipe:
The entrance length is short and we can assume the flow is hydrodynamically and thermally fully developed
everywhere. As shown in the graph below, the fluid
ME315 F2015 Quiz # 2 09/02/2015
Number:
Name:
Signature:
Rank their thermal conductivity from high to low: (near room temperature, 1 being the highest)
( 2 ) Silver
(4 or 5) Foams
( 6 ) Air
( 3 ) Glass
( 1 ) Diamond
(5 or 4) Oil and Water
True or false:
(
ME315 F2015 Quiz # 4 09/16/2015
Number:
Name:
Signature:
Draw the circuit: Draw an effective circuit of the composite wall below (no need to label T, Rt and qx).
B
T 1
A
D
T 2
C
True or false: Consider applying a thermal insulation layer around a hot meta
Name:
Problem 1 (20 points)
Consider a micron sized spherical coal particle moving inside a combustor of approximately 5 m in
length as shown in the figure below. (The drawing is not to scale. The reactor walls extend on both
sides in the vertical directi
PROBLEM 2.16
KNOWN: A rod of constant thermal conductivity k and variable cross-sectional area Ax(x) = Aoeax
where Ao and a are constants.
FIND: (a) Expression for the conduction heat rate, qx(x); use this expression to determine the
temperature distribut
(1) Consider steady 1D heat conduction in the trapezoidal domain shown below. The domain
extends infinitely into the page. There is a constant volumetric heat generation rate q in the
domain.
Insulation
dx
q
a
b
x
L
Domain extends
infinitely into the page
ME 315: Heat And Mass Transfer
Fall 2016
Mechanical Engineering
Haorong Chen
Outline
Response to evaluation
Blank handout:
Filled handout:
Examples:
Derivation:
a day before lecture
post on the same day
worked in better format
Lecture outline:
Internal fl
Outline
Announcement:
Homework due next lecture
Homework ready to pick up each Wednesday
Outline:
Finite volume method for transient conduction problem
Introduction to convection
Problem statement
Lumped capacitance model
Analytical solution
Complex geome
ME315 F2015 Quiz # 10 11/18/2015
Number:
Name:
Signature:
As shown in the right figure, a diffuse plate has a spectral emissivity
which is independent on the surface temperature. Recall the Wiens
displacement law:
max T 3000 m K
.
a) Qualitatively draw th
PROBLEM 3.90
KNOWN: Geometry and boundary conditions of a nuclear fuel element.
FIND: (a) Expression for the temperature distribution in the fuel, (b) Form of temperature
distribution for the entire system.
SCHEMATIC:
ASSUMPTIONS: (1) One-dimensional heat
PROBLEM 6.66
KNOWN: Mass transfer experimental results on a half-sized model representing an engine strut.
1/3
FIND: (a) The coefficients C and m of the correlation Sh L = CRe m
for the mass transfer
L Sc
results, (b) Average heat transfer coefficient, h,
PROBLEM 4.31
KNOWN: Dimensions, shape factor, and thermal conductivity of square rod with drilled interior hole.
Interior and exterior convection conditions.
FIND: Heat rate and surface temperatures.
SCHEMATIC:
ASSUMPTIONS: (1) Steady-state, two-dimension
PROBLEM 3.3
KNOWN: Temperatures and convection coefficients associated with air at the inner and outer surfaces
of a rear window.
FIND: (a) Inner and outer window surface temperatures, Ts,i and Ts,o, and (b) Ts,i and Ts,o as a function of
the outside air
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