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 | University of Virginia |  |
MECHANICAL ENGINEERING.
The subjects embraced in this course are those which may be considered
as belonging especially or exclusively to the province of the
mechanical engineer. They are treated under the following divisions:
1. Steam Power Plants.
The topics assigned to the first term are such as relate to the general
organization and layout of modern steam power plants. The analysis
of fuels, their heating power, their combustion, and the furnaces in
which they are burned, are first considered. The construction of
boilers is next taken up and the forms of setting, the materials used
in their construction, the design of the joints and attachments, and
the determination of the proportions of the boiler for a given duty
are carefully studied. The principal types of steam engine are then
discussed, the conditions determining the choice of high or low speed,
simple or compound, condensing or non-condensing engines are developed,
and the rules for fixing their general proportions are investigated.
The design of the condenser is next studied, its standard forms
are described and illustrated, its proportion established, and the conditions
of its utility are defined. Finally the methods of testing a
thermometers, gauges, calorimeters, indicators, dynamometers
and so on employed in the tests are discussed, and the methods
of standardizing and using them are established. A complete set of
laboratory exercises in the performance of such tests is given, and the
student is made familiar with the standard methods of testing, and
practised in the reduction and analysis of the results.
2. Steam Engine Design.
The work of the second term consists in a systematic study of the
problem of steam engine design. A type of engine having been
selected from the results reached in the first division of the work,
rules are developed from rational principles and experimental data
for the correct proportions of all its details—cylinders and cylinder
ends, pistons and piston rods, wrist pins, crank pins, connecting rods,
shafts, cranks, cross heads, guides, and so on. The indicated diagram
of the projected engine and the resulting energy curves are next
studied, the weight and proportions of the fly-wheel are determined,
and the inertia strains on the frame and foundations of the engine
are ascertained and allowed for. The laws of construction and operation
of the governor are next developed and rules are worked out
for the design of governors of all the standard types. The problems
of valve gearing are then approached and solved by both analytical
and graphical processes, all the usual forms of gearing being minutely
discussed. In conclusion the internal resistances of the engine are
investigated, together with the methods of lubrication, and the losses
of energy from friction, and the probable brake horse-power is determined
for various steam pressures and speeds. The course in design
is followed by the student not only in the lectures, but in practical
exercises at the drawing board, so arranged as to furnish by their
results a complete set of steam engine details.
3. Transmission of Power.
In the last section of the course are considered the problems connected
with the transmission of power. Shaft transmissions are first
studied, their proportions are determined, the losses of energy to
which they are subjected are estimated, and the methods of testing
these by means of suitable transmission dynamometers are explained.
Like investigations follow for belt, rope and teledynamic transmissions;
for transmission by toothed gear; and for hydraulic and pneumatic
transmissions. Illustrations drawn from current engineering
practice are used to give definiteness to the student's conceptions of
these important applications of engineering theory. The attempt is
of transmission and to fix the economic limits of its application.
| University of Virginia | |