Flow past a sphere at Mach 1.53: An object moving through a fluid at supersonic speed 1Mach number greater than one2 creates a shock wave 1a discontinuity in flow conditions shown by the dark curved line2, which is heard as a sonic boom as the object pass
Motion of water induced by surface waves: As a wave passes along the surface of the water, the water particles follow elliptical paths. There is no net motion of the water, just a periodic, cyclic trajectory 1neutrally buoyant particles in water2. 1Photog
Impulsive start of flow past an array of cylinders: The complex structure of laminar flow past a relatively simple geometric structure illustrates why it is often difficult to obtain exact analytical results for external flows. 1Dye in water.2 1Photograph
Turbulent jet: The jet of water from the pipe is turbulent. The complex, irregular, unsteady structure typical of turbulent flows is apparent. (Laserinduced fluorescence of dye in water.) (Photography by P. E. Dimotakis, R. C. Lye, and D. Z. Papantoniou.)
Flow past a circular cylinder with Re 2000: The pathlines of flow past any circular cylinder 1regardless of size, velocity, or fluid2 are as shown provided that the dimensionless parameter called the Reynolds number, Re, is equal to 2000. For other values
Flow past an inclined plate: The streamlines of a viscous fluid flowing slowly past a two-dimensional object placed between two closely spaced plates 1a Hele-Shaw cell2 approximate inviscid, irrotational 1potential2 flow. 1Dye in water between glass plate
A jet of water injected into stationary water: Upon emerging from the slit at the left, the jet of fluid loses some of its momentum to the surrounding fluid. This causes the jet to slow down and its width to increase (air bubbles in water). (Photograph co
A vortex ring: The complex, three-dimensional structure of a smoke ring is indicated in this cross-sectional view. 1Smoke in air.2 1Photograph courtesy of R. H. Magarvey and C. S. MacLatchy, Ref. 4.2
Fluid Kinematics
In the previous three chapters we have
An image of hurricane Allen viewed via satellite: Although there is considerable motion and structure to a hurricane, the pressure variation in the vertical direction is approximated by the pressure-depth relationship for a static fluid. 1Visible and infr
The break-up of a fluid jet into drops is a function of fluid properties such as density, viscosity, and surface tension. [Reprinted with permission from American Institute of Physics (Ref. 6) and the American Association for the Advancement of Science (R
Appendices
823
APPENDIX
A
Unit Conversion Tables
1
The following tables express the definitions of miscellaneous units of measure as exact numerical multiples of coherent SI units and provide multiplying factors for converting numbers and miscellaneous un
Answers to Selected Even-Numbered
Homework Problems
*Problems marked with an * are intended to be solved with the aid of a programmable calculator or computer. Chapter 1.4 1.6 1.8 1.10 1.12 1.14 1.16 1 1a2 FL 2; 1b2 FL 3; 1c2 FL 1b2 dimensionless; yes dim
Chapter 9: Phase Diagrams
ISSUES TO ADDRESS.
When we combine two elements.
what equilibrium state do we get?
In particular, if we specify.
-a composition (e.g., wt% Cu - wt% Ni), and -a temperature (T )
then.
How many phases do we get? What is the compo
Professor Mohamad Al-Sheikhly
Department of Materials Science and Engineering and
University of Maryland
College Park, MD
Introduction to Materials Engineering
ENMA 300 and ENME382
Description: Structure of materials, chemical composition, phase transform
Waqaas Ali
ENMA-300
Metallography
Metallography is basically the study of metals often through the methods of
microcopy. Metal surfaces and fractures are examined with the eye or with a magnifying
glass or metallurgical or binocular microscope at magnific
ENMA 300 and ENME 382
Homework 1
Due: Friday, Feb. 4, 2011
1. Predict the type of bonding that holds the atoms/molecules together in the following solid
materials. Explain why you have made the prediction for each material. Where appropriate
include calcu
HW 4
ENME 382
4.3 Below, molecular weight data for a polytetrafluoroethylene material are tabulated. Compute (a) the numberaverage molecular weight, (b) the weight-average molecular weight, and (c) the degree of polymerization.
Molecular Weight
Range (g/m
Department of Materials Science and Engineering
University of Maryland
College Park, MD
ENMA 300: Problem Set #3
SOLUTIONS
1. Lattices (2D and 3D)
Identify the lattices and the unit cell in the following images:
(a)
[Source: M. C. Escher]
The white outlin
ENMA 300
Homework 11
Due: Dec 7, 2010
1. This is a combination of problems 10.5 and 10.8 because as a combination they provide
important practice for interpreting phase diagrams. Remember that while book gives formulas
for converting weight percent to mol
ENMA 300: Problem Set #10
1. Under what conditions can Ficks first law be used to solve diffusion problems?
It can be used to solve diffusion problems provided the concentration gradient does not
change over time.
2. Silica can be either a crystalline sol
HOMEWORK # 9
Name _
ENMA 300
DUE: Thursday, November 11, 2010
1.
A through-thickness crack of length 0.5 mm grows from a 10 mm diameter hole in a 25
mm thick plate of hardened Al that has the properties listed below. The crack is subjected
to a nominal st
ENMA 300
Homework 8
1a) The critical resolved shear stress for copper is 0.48 MPa (70 psi). Determine the minimum possible
yield strength for a single crystal of Cu pulled in tension.
bi) A single crystal of a metal that has the BCC crystal structure is o
Prof. Rabin: [email protected]; X53382; CHE 1110B
ENMA 300: Problem Set #7
Date Posted: Thr 10/21/10
Time Due: Thr 10/28/10 5PM.
Dislocations
1. A metal crystal has a Burgers vector of length 0.272nm. If the lattice parameter a is 0.314, is
the metal crystal s
ENMA 300: Solutions Set #7
Dislocations
1. A metal crystal has a Burgers vector of length 0.272nm. If the lattice parameter a is 0.314, is
the metal crystal structure FCC or BCC?
The Burgers vector is (a/2)*[110] in FCC structures and (a/2)*[111] in BCC s
Department of Materials Science and Engineering
University of Maryland
College Park, MD
ENMA 300: Problem Set #3
1. Lattices (2D and 3D)
Identify the lattices and the unit cell in the following images:
(a)
(b)
[Source: M. C. Escher]
[Source: M.C. Escher]
Homework # 6
5.5: (a) Atomic radius, crystal structure, electronegativity, and the most common valence are tabulated
below, for several elements. Which of these elements would you expect to form a substitutional solid
solution with nickel having complete
Homework # 6
5.5: (a) Atomic radius, crystal structure, electronegativity, and the most common valence are tabulated
below, for several elements. Which of these elements would you expect to form a substitutional solid
solution with nickel having complete
HW 5
ENMA 300
5.1
5.12 Some hypothetical alloy is composed of 25 wt% of metal A and 75 wt% of metal B. If the densities of metals A
and B are 6.17 and 8.00 g/cm3, respectively, whereas their respective atomic weights are 171.3 and 162.0 g/mol,
determine w
HW 5
ENMA 300
5.1 Calculate the fraction of atom sites that are vacant for copper at its melting temperature of 1084degC. Assume
an energy for vacancy formation of 0.90 eV/atom.
5.12 Some hypothetical alloy is composed of 25 wt% of metal A and 75 wt% of m
HOMEWORK # 9
Name _
ENMA 300
DUE: Thursday, November 11, 2010
1. A through-thickness crack of length 0.5 mm grows from a 10 mm diameter hole
in a 25 mm thick plate of hardened Al that has the properties listed below. The
crack is subjected to a nominal st