FLYING MACHINES_ CONSTRUCTION and OPERATION(飞行器：结构和原理)
VIP免费
2024-12-26
0
0
540.17KB
153 页
5.9玖币
侵权投诉
FLYING MACHINES: CONSTRUCTION and OPERATION
1
FLYING MACHINES:
CONSTRUCTION and
OPERATION
By W.J. Jackman, M.E.
AND THOS. H. RUSSELL, A.M., M.E. 1912
FLYING MACHINES: CONSTRUCTION and OPERATION
2
CHAPTER I.
EVOLUTION OF TWO-SURFACE FLYING MACHINE.
By Octave Chanute.
I am asked to set forth the development of the "two- surface" type of
flying machine which is now used with modifications by Wright Brothers,
Farman, [1]Delagrange, Herring and others.
[1] Now dead.
This type originated with Mr. F. H. Wenham, who patented it in
England in 1866 (No. 1571), taking out provisional papers only. In the
abridgment of British patent Aeronautical Specifications (1893) it is
described as follows:
"Two or more aeroplanes are arranged one above the other, and
support a framework or car containing the motive power. The aeroplanes
are made of silk or canvas stretched on a frame by wooden rods or steel
ribs. When manual power is employed the body is placed horizontally, and
oars or propellers are actuated by the arms or legs.
"A start may be obtained by lowering the legs and running down hill
or the machine may be started from a moving carriage. One or more screw
propellers may be applied for propelling when steam power is employed.
On June 27, 1866, Mr. Wenham read before the "Aeronautical Society
of Great Britain," then recently organized, the ablest paper ever presented
to that society, and thereby breathed into it a spirit which has continued to
this day. In this paper he described his observations of birds, discussed the
laws governing flight as to the surfaces and power required both with
wings and screws, and he then gave an account of his own experiments
with models and with aeroplanes of sufficient size to carry the weight of a
man.
Second Wenham Aeroplane.
His second aeroplane was sixteen feet from tip to tip. A trussed spar at
the bottom carried six superposed bands of thin holland fabric fifteen
inches wide, connected with vertical webs of holland two feet apart, thus
FLYING MACHINES: CONSTRUCTION and OPERATION
3
virtually giving a length of wing of ninety-six feet and one hundred and
twenty square feet of supporting surface. The man was placed horizontally
on a base board beneath the spar. This apparatus when tried in the wind
was found to be unmanageable by reason of the fluttering motions of the
fabric, which was insufficiently stiffened with crinoline steel, but Mr.
Wenham pointed out that this in no way invalidated the principle of the
apparatus, which was to obtain large supporting surfaces without
increasing unduly the leverage and consequent weight of spar required, by
simply superposing the surfaces.
This principle is entirely sound and it is surprising that it is, to this day,
not realized by those aviators who are hankering for monoplanes.
Experiments by Stringfellow.
The next man to test an apparatus with superposed surfaces was Mr.
Stringfellow, who, becoming much impressed with Mr. Wenham's
proposal, produced a largish model at the exhibition of the Aeronautical
Society in 1868. It consisted of three superposed surfaces aggregating 28
square feet and a tail of 8 square feet more. The weight was under 12
pounds and it was driven by a central propeller actuated by a steam engine
overestimated at one-third of a horsepower. It ran suspended to a wire on
its trials but failed of free flight, in consequence of defective equilibrium.
This apparatus has since been rebuilt and is now in the National Museum
of the Smithsonian Institution at Washington. Linfield's Unsuccessful
Efforts.
In 1878 Mr. Linfield tested an apparatus in England consisting of a
cigar-shaped car, to which was attached on each side frames five feet
square, containing each twenty-five superposed planes of stretched and
varnished linen eighteen inches wide, and only two inches apart, thus
reminding one of a Spanish donkey with panniers. The whole weighed two
hundred and forty pounds. This was tested by being mounted on a flat car
behind a locomotive going 40 miles an hour. When towed by a line fifteen
feet long the apparatus rose only a little from the car and exhibited such
unstable equilibrium that the experiment was not renewed. The lift was
only about one- third of what it would have been had the planes been
FLYING MACHINES: CONSTRUCTION and OPERATION
4
properly spaced, say their full width apart, instead of one-ninth as
erroneously devised.
Renard's "Dirigible Parachute."
In 1889 Commandant Renard, the eminent superintendent of the
French Aeronautical Department, exhibited at the Paris Exposition of that
year, an apparatus experimented with some years before, which he termed
a "dirigible parachute." It consisted of an oviform body to which were
pivoted two upright slats carrying above the body nine long superposed
flat blades spaced about one-third of their width apart. When this
apparatus was properly set at an angle to the longitudinal axis of the body
and dropped from a balloon, it travelled back against the wind for a
considerable distance before alighting. The course could be varied by a
rudder. No practical application seems to have been made of this device by
the French War Department, but Mr. J. P. Holland, the inventor of the
submarine boat which bears his name, proposed in 1893 an arrangement of
pivoted framework attached to the body of a flying machine which
combines the principle of Commandant Renard with the curved blades
experimented with by Mr. Phillips, now to be noticed, with the addition of
lifting screws inserted among the blades.
Phillips Fails on Stability Problem.
In 1893 Mr. Horatio Phillips, of England, after some very interesting
experiments with various wing sections, from which he deduced
conclusions as to the shape of maximum lift, tested an apparatus
resembling a Venetian blind which consisted of fifty wooden slats of
peculiar shape, 22 feet long, one and a half inches wide, and two inches
apart, set in ten vertical upright boards. All this was carried upon a body
provided with three wheels. It weighed 420 pounds and was driven at 40
miles an hour on a wooden sidewalk by a steam engine of nine
horsepower which actuated a two-bladed screw. The lift was satisfactory,
being perhaps 70 pounds per horsepower, but the equilibrium was quite
bad and the experiments were discontinued. They were taken up again in
1904 with a similar apparatus large enough to carry a passenger, but the
longitudinal equilibrium was found to be defective. Then in 1907 a new
FLYING MACHINES: CONSTRUCTION and OPERATION
5
machine was tested, in which four sets of frames, carrying similar sets of
slat "sustainers" were inserted, and with this arrangement the longitudinal
stability was found to be very satisfactory. The whole apparatus, with the
operator, weighed 650 pounds. It flew about 200 yards when driven by a
motor of 20 to 22 h.p. at 30 miles an hour, thus exhibiting a lift of about
32 pounds per h.p., while it will be remembered that the aeroplane of
Wright Brothers exhibits a lifting capacity of 50 pounds to the h.p.
Hargrave's Kite Experiments.
After experimenting with very many models and building no less than
eighteen monoplane flying model machines, actuated by rubber, by
compressed air and by steam, Mr. Lawrence Hargrave, of Sydney, New
South Wales, invented the cellular kite which bears his name and made it
known in a paper contributed to the Chicago Conference on Aerial
Navigation in 1893, describing several varieties. The modern construction
is well known, and consists of two cells, each of superposed surfaces with
vertical side fins, placed one behind the other and connected by a rod or
frame. This flies with great steadiness without a tail. Mr. Hargrave's idea
was to use a team of these kites, below which he proposed to suspend a
motor and propeller from which a line would be carried to an anchor in the
ground. Then by actuating the propeller the whole apparatus would move
forward, pick up the anchor and fly away. He said: "The next step is clear
enough, namely, that a flying machine with acres of surface can be safely
got under way or anchored and hauled to the ground by means of the
string of kites."
The first tentative experiments did not result well and emphasized the
necessity for a light motor, so that Mr. Hargrave has since been engaged in
developing one, not having convenient access to those which have been
produced by the automobile designers and builders.
Experiments With Glider Model.
And here a curious reminiscence may be indulged in. In 1888 the
present writer experimented with a two-cell gliding model, precisely
similar to a Hargrave kite, as will be confirmed by Mr. Herring. It was
frequently tested by launching from the top of a three-story house and
FLYING MACHINES: CONSTRUCTION and OPERATION
6
glided downward very steadily in all sorts of breezes, but the angle of
descent was much steeper than that of birds, and the weight sustained per
square foot was less than with single cells, in consequence of the lesser
support afforded by the rear cell, which operated upon air already set in
motion downward by the front cell, so nothing more was done with it, for
it never occurred to the writer to try it as a kite and he thus missed the
distinction which attaches to Hargrave's name.
Sir Hiram Maxim also introduced fore and aft superposed surfaces in
his wondrous flying machine of 1893, but he relied chiefly for the lift
upon his main large surface and this necessitated so many guys, to prevent
distortion, as greatly to increase the head resistance and this, together with
the unstable equilibrium, made it evident that the design of the machine
would have to be changed.
How Lilienthal Was Killed.
In 1895, Otto Lilienthal, the father of modern aviation, the man to
whose method of experimenting almost all present successes are due, after
making something like two thousand glides with monoplanes, added a
superposed surface to his apparatus and found the control of it much
improved. The two surfaces were kept apart by two struts or vertical posts
with a few guy wires, but the connecting joints were weak and there was
nothing like trussing. This eventually cost his most useful life. Two weeks
before that distressing loss to science, Herr Wilhelm Kress, the
distinguished and veteran aviator of Vienna, witnessed a number of glides
by Lilienthal with his double-decked apparatus. He noticed that it was
much wracked and wobbly and wrote to me after the accident: "The
connection of the wings and the steering arrangement were very bad and
unreliable. I warned Herr Lilienthal very seriously. He promised me that
he would soon put it in order, but I fear that he did not attend to it
immediately."
In point of fact, Lilienthal had built a new machine, upon a different
principle, from which he expected great results, and intended to make but
very few more flights with the old apparatus. He unwisely made one too
many and, like Pilcher, was the victim of a distorted apparatus. Probably
FLYING MACHINES: CONSTRUCTION and OPERATION
7
one of the joints of the struts gave way, the upper surface blew back and
Lilienthal, who was well forward on the lower surface, was pitched
headlong to destruction.
Experiments by the Writer.
In 1896, assisted by Mr. Herring and Mr. Avery, I experimented with
several full sized gliding machines, carrying a man. The first was a
Lilienthal monoplane which was deemed so cranky that it was discarded
after making about one hundred glides, six weeks before Lilienthal's
accident. The second was known as the multiple winged machine and
finally developed into five pairs of pivoted wings, trussed together at the
front and one pair in the rear. It glided at angles of descent of 10 or 11
degrees or of one in five, and this was deemed too steep. Then Mr. Herring
and myself made computations to analyze the resistances. We attributed
much of them to the five front spars of the wings and on a sheet of cross-
barred paper I at once drew the design for a new three-decked machine to
be built by Mr. Herring.
Being a builder of bridges, I trussed these surfaces together, in order to
obtain strength and stiffness. When tested in gliding flight the lower
surface was found too near the ground. It was taken off and the remaining
apparatus now consisted of two surfaces connected together by a girder
composed of vertical posts and diagonal ties, specifically known as a
"Pratt truss." Then Mr. Herring and Mr. Avery together devised and put on
an elastic attachment to the tail. This machine proved a success, it being
safe and manageable. Over 700 glides were made with it at angles of
descent of 8 to 10 degrees, or one in six to one in seven.
First Proposed by Wenham.
The elastic tail attachment and the trussing of the connecting frame of
the superposed wings were the only novelties in this machine, for the
superposing of the surfaces had first been proposed by Wenham, but in
accordance with the popular perception, which bestows all the credit upon
the man who adds the last touch making for success to the labors of his
predecessors, the machine has since been known by many persons as the
"Chanute type" of gliders, much to my personal gratification.
FLYING MACHINES: CONSTRUCTION and OPERATION
8
It has since been improved in many ways. Wright Brothers,
disregarding the fashion which prevails among birds, have placed the tail
in front of their apparatus and called it a front rudder, besides placing the
operator in horizontal position instead of upright, as I did; and also
providing a method of warping the wings to preserve equilibrium. Farman
and Delagrange, under the very able guidance and constructive work of
Voisin brothers, then substituted many details, including a box tail for the
dart-like tail which I used. This may have increased the resistance, but it
adds to the steadiness. Now the tendency in France seems to be to go back
to the monoplane.
Monoplane Idea Wrong.
The advocates of the single supporting surface are probably mistaken.
It is true that a single surface shows a greater lift per square foot than
superposed surfaces for a given speed, but the increased weight due to
leverage more than counterbalances this advantage by requiring heavy
spars and some guys. I believe that the future aeroplane dynamic flier will
consist of superposed surfaces, and, now that it has been found that by
imbedding suitably shaped spars in the cloth the head resistance may be
much diminished, I see few objections to superposing three, four or even
five surfaces properly trussed, and thus obtaining a compact, handy,
manageable and comparatively light apparatus.[2]
[2] Aeronautics.
FLYING MACHINES: CONSTRUCTION and OPERATION
9
CHAPTER II.
THEORY, DEVELOPMENT, AND USE.
While every craft that navigates the air is an airship, all airships are
not flying machines. The balloon, for instance, is an airship, but it is not
what is known among aviators as a flying machine. This latter term is
properly used only in referring to heavier-than-air machines which have
no gas-bag lifting devices, and are made to really fly by the application of
engine propulsion.
Mechanical Birds.
All successful flying machines--and there are a number of them--are
based on bird action. The various designers have studied bird flight and
soaring, mastered its technique as devised by Nature, and the modern
flying machine is the result. On an exaggerated, enlarged scale the
machines which are now navigating the air are nothing more nor less than
mechanical birds.
Origin of the Aeroplane.
Octave Chanute, of Chicago, may well be called "the developer of the
flying machine." Leaving balloons and various forms of gas-bags out of
consideration, other experimenters, notably Langley and Lilienthal,
antedated him in attempting the navigation of the air on aeroplanes, or
flying machines, but none of them were wholly successful, and it
remained for Chanute to demonstrate the practicability of what was then
called the gliding machine. This term was adopted because the apparatus
was, as the name implies, simply a gliding machine, being without motor
propulsion, and intended solely to solve the problem of the best form of
construction. The biplane, used by Chanute in 1896, is still the basis of
most successful flying machines, the only radical difference being that
motors, rudders, etc., have been added.
Character of Chanute's Experiments.
It was the privilege of the author of this book to be Mr. Chanute's
guest at Millers, Indiana, in 1896, when, in collaboration with Messrs.
FLYING MACHINES: CONSTRUCTION and OPERATION
10
Herring and Avery, he was conducting the series of experiments which
have since made possible the construction of the modern flying machine
which such successful aviators as the Wright brothers and others are now
using. It was a wild country, much frequented by eagles, hawks, and
similar birds. The enthusiastic trio, Chanute, Herring and Avery, would
watch for hours the evolutions of some big bird in the air, agreeing in the
end on the verdict, "When we master the principle of that bird's soaring
without wing action, we will have come close to solving the problem of
the flying machine."
Aeroplanes of various forms were constructed by Mr. Chanute with the
assistance of Messrs. Herring and Avery until, at the time of the writer's
visit, they had settled upon the biplane, or two-surface machine. Mr.
Herring later equipped this with a rudder, and made other additions, but
the general idea is still the basis of the Wright, Curtiss, and other machines
in which, by the aid of gasolene motors, long flights have been made.
Developments by the Wrights.
In 1900 the Wright brothers, William and Orville, who were then in
the bicycle business in Dayton, Ohio, became interested in Chanute's
experiments and communicated with him. The result was that the Wrights
took up Chanute's ideas and developed them further, making many
additions of their own, one of which was the placing of a rudder in front,
and the location of the operator horizontally on the machine, thus
diminishing by four-fifths the wind resistance of the man's body. For three
years the Wrights experimented with the glider before venturing to add a
motor, which was not done until they had thoroughly mastered the control
of their movements in the air.
Limits of the Flying Machine.
In the opinion of competent experts it is idle to look for a commercial
future for the flying machine. There is, and always will be, a limit to its
carrying capacity which will prohibit its employment for passenger or
freight purposes in a wholesale or general way. There are some, of course,
who will argue that because a machine will carry two people another may
be constructed that will carry a dozen, but those who make this contention
摘要：
展开>>
收起<<
FLYINGMACHINES:CONSTRUCTIONandOPERATION1FLYINGMACHINES:CONSTRUCTIONandOPERATIONByW.J.Jackman,M.E.ANDTHOS.H.RUSSELL,A.M.,M.E.1912FLYINGMACHINES:CONSTRUCTIONandOPERATION2CHAPTERI.EVOLUTIONOFTWO-SURFACEFLYINGMACHINE.ByOctaveChanute.Iamaskedtosetforththedevelopmentofthe"two-surface"typeofflyingmachinewh...
声明：本站为文档C2C交易模式，即用户上传的文档直接被用户下载，本站只是中间服务平台，本站所有文档下载所得的收益归上传人(含作者)所有。玖贝云文库仅提供信息存储空间，仅对用户上传内容的表现方式做保护处理，对上载内容本身不做任何修改或编辑。若文档所含内容侵犯了您的版权或隐私，请立即通知玖贝云文库，我们立即给予删除！
相关推荐
-
【词汇变形总汇】2025高考词汇变形总汇 - 教师版VIP免费
2024-12-06 3 -
【超简37页】新课标高考英语考纲3500词汇VIP免费
2024-12-06 4 -
《高考英语3500词详解》（WORD版）VIP免费
2024-12-06 13 -
《高考英语3500词详解》VIP免费
2024-12-06 11 -
高中英语-[教师版]80天通关高考3500词汇VIP免费
2024-12-06 12 -
高中人教选修7课文逐句翻译VIP免费
2024-12-06 7 -
高中人教选修7课文原文及翻译VIP免费
2024-12-06 13 -
高中人教必修4课文逐句翻译VIP免费
2024-12-06 7 -
高中人教必修4课文原文及翻译VIP免费
2024-12-06 13 -
高考英语核心高频688词汇VIP免费
2024-12-06 10
分类：外语学习
价格：5.9玖币
属性：153 页
大小：540.17KB
格式：PDF
时间：2024-12-26
相关内容
-
3-专题三 牛顿运动定律 2-教师专用试题
分类：中学教育
时间：2025-04-07
标签：无
格式：DOCX
价格：5.9 玖币
-
2-专题二 相互作用 2-教师专用试题
分类：中学教育
时间：2025-04-07
标签：无
格式：DOCX
价格：5.9 玖币
-
6-专题六 机械能 2-教师专用试题
分类：中学教育
时间：2025-04-07
标签：无
格式：DOCX
价格：5.9 玖币
-
4-专题四 曲线运动 2-教师专用试题
分类：中学教育
时间：2025-04-08
标签：无
格式：DOCX
价格：5.9 玖币
-
5-专题五 万有引力与航天 2-教师专用试题
分类：中学教育
时间：2025-04-08
标签：无
格式：DOCX
价格：5.9 玖币
渝公网安备50010702506394
