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M.L.Institute of Diploma Studies,Bhandu A Project Report On DESI! O" #$DRA%LI& 'A&( ) A!AL$SIS Su*mitted +o ujarat +echnoloical +echnoloical %ni-ersit
Su*mitted B RA!A #I+E!DRASI!# (. PA+EL SA+IS# #.
/0123/2404/5 /0123/240/67
8A!9ARA RA!&##OD M.
/0123/24044:
RA+#OD #I+ES# M.
/0123/240/1/
uided B "acult !ame ; Mr.M. (. PA+EL Mechanical Enineerin Department
UNDEFINED PROBLEM The student information
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Name of student
(In Capital
Letters)
urname Father!s Name
Name
Enro""ment Num#er $ontact Num#ers Mo#%
Land"ine%
Emai" ID $o""ege Name
$o""ege $ode%
Branch
emester%
tudent Team
Name%
Enro""ment Num#ers
&. '. (. ).
tudent ignature
%'ARA+ +E&#!OLOI&AL %!I8ERSI+$ Page no:2
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Name of student
(In Capital
Letters)
urname Father!s Name
Name
Enro""ment Num#er $ontact Num#ers Mo#%
Land"ine%
Emai" ID $o""ege Name
$o""ege $ode%
Branch
emester%
tudent Team
Name%
Enro""ment Num#ers
&. '. (. ).
tudent ignature
%'ARA+ +E&#!OLOI&AL %!I8ERSI+$ Page no:2
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M.L. I!S+I+%+E O" DIPLOMA DIPLOM A S+%DIES B#A!D%
$ERTIFI$*TE This is to certify that Mr./Ms from
College having Enrolment No:
has completed UDP/ Semester Pro!ect "eport
having title
#n a gro$p consisting of
persons $nder the g$idance of the %ac$lty &$ide
#nstit$te &$ide'UDP
(ead of Department
*$+NO,LED-EMENT
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I am deeply indebted to my revered supervisor M.. P!"#L $or inspiring% en&ouraging and guiding me in my pro'e&t or it*out *is suggestion timely guidan&e and &o+operation. I &on$ess% I ould not *ave &ompleted my Pro'e& o'e&tt ,or or *e *as *as been been &ons &onsta tant ntly ly a sour sour&e &e o$ motivation $or &omplete t*is t*esis and model. I am very mu&* t*an$ul to -. . /0,!MI% *ead o$ Me&* Me&*an ani& i&al al depa depart rtme ment nt M.L. M.L.I. I.. .. . !4 !45 5 6 ..-. P!"#L I-% $or providing me all t*e ne&essary $a&ility $or my pro'e&t or. I oe a orld o$ gratitude to t*e aut*orities o$ M.L.I... !45 t*ey granted me permission *enever I re7uested not only t*at t*ey also provided me e8&ellent $a&ility o$ my or. I ould lie to e8press my t*ans to my pro$. -. M. /0/# 6 pro$. -. M. P!"#L *o *ave assisted me at various stages o$ my ,or. I is* to e8press my *eart le$t gratitude to my $rie $riend nds. s. 9or t*ei t*eirr &eas &easel eles ess s *elp *elp and and &o+op &o+oper erat atio ion n all all t*roug*out t*is onerous tas. Last but not list I oe *ave a ord o$ gratitude to t*e almig*ty $or providing me *idden strengt* and inspiration. I also t*an all *o *ave supported me a lot in my pro'e&t or. Page no:
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!"-!C": Now a day, infrastructure development is very fast growing, for that the use of R.C.C construction machinery is very widely used, but in any R.C.C construction machinery proper Mixing of raw material for Concrete is major problem. Proper mixing of raw material is important tas in any construction, for that we are use latest e!uipments which are mechanically and hydraulically combined operated mostly. DEI-N OF OPEN /DR*ULI$ 0*$+ 1 *N*L/E is one of them which are operated by two prime movers one prime mover is use for hydraulic system operation for operating the hoper and other for operating drum for proper mixing of concret"he wor presented herein is mainly divided into the three chapters. "he first chapter introduces the concrete benching mixing machine with problem formulation and provides motivation for the project. "he second chapter presents the current state of mixing machine research as presented in the form of scientific literature review.
P-0;#C" #9I4!"I04: # hydraulic jac is a device used to lift heavy loads. "he device itself is light, compact and portable, but is capable of exerting great force. "he device pushes li!uid against a piston$ pressure is built in the jac%s container. "he jac is based on Pascal%s law that the pressure of a li!uid in a container is the same at all point
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TABLE OF CONTENTS No.
Titles
Page no.
#cnowledgement
1
#bstract
8
"ables &f Contents
9
'ist &f (igure Nomenclature
Introduction
)*
).)
+efinition &f ydraulic -ac
)
).*
/ntroduction
)
).
Pascal0s 'aw
)
).1
istory
)1
).2
(eatures
)1
).3
Classification &f -ac
)1
).3.)
Mechanical -ac
)2
).3.*
ydraulic -ac
)2
).3.
Pneumatic -ac
)3
).3.1
4trand -ac
)5
).5
6oring Principal78
)9
).9
6oring &f ydraulic -ac
)9
).:
#dvantages
*)
Ch.1
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` ).);
#pplications
*
Design O !"draulic S"ste#
*1
*.)
ydraulic
*2
*.).)
Pressure #nd (orce
*2
*.*
*5
*.
Parts &f ydraulic -ac
*:
*..)
Parts &f Cylinder
*:
*..).)
C='/N+>R <#RR>'
*:
*..).*
C='/N+>R <#4> &R C#P
*:
*..).
C='/N+>R >#+78
;
*..*
Piston Rod78
;
*..*.)
Piston Rod Construction
;
*..*.).)
8Metallic Coatings78
;
*..*.).*
C>R#M/C C&#"/N?478
)
*..*.).
'ength78
)
*..*.
?land @>nd CapA78
)
Ch.$
C#'CB'#"/&N (&R +>4/?N
*
Ch.%
'/"R>#C>R R//>6
5
Ch.&
R>(>R>NC>4
19
Ch.2
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C*apter 1
Introdu&tion
Cha'ter 1
Introduction
1.1(Deination O !"draulic )ac*+( # hydraulic jac is a device used to lift heavy loads. "he device itself is light, compact and portable, but is capable of exerting great force. "he device pushes li!uid against a piston$ pressure is built in the jac%s container. "he jac is based on Pascal%s law that the pressure of a li!uid in a container is the same at all points. Page no:@
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1.2(Introduction+( # hydraulic jac is a jac that uses a li!uid to push against a piston. "his is based on Pascal0s Principle. "he principle states that pressure in a closed container is the same at all points. /f there are two cylinders connected, applying force to the smaller cylinder will result in the same amount of pressure in the larger cylinder. owever, since the larger cylinder has more area, the resulting force will be greater. /n other words, an increase in area leads to an increase in force. "he greater the difference in siDe between the two cylinders, the greater the increase in the force will be. # hydraulic jac operates based on this two cylinder system.
1.$(Pascal,s la- +( Pressure on a confined fluid is transmitted undiminished and acts with e!ual force on e!ual areas and at :; degrees to the container wall.
# fluid, such as oil, is displaced when either piston is pushed inward. "he small piston, for a given distance of movement, displaces a smaller amount of volume than the large piston, which is proportional to the ratio of areas of the heads of the pistons. "herefore, the small piston must be moved a large distance to get the large piston to move significantly. "he distance the large piston will move is the distance that the small piston is moved divided by the ratio of the areas of the heads of the pistons. "his is how energy, in the form of wor in this case, is conserved and the 'aw of Conservation of >nergy is satisfied. 6or is force times distance, and since the force is increased on the larger piston, the distance the force is applied over must be decreased.
1.%(!istor"+( "he &rigin &f ydraulic -acs Can
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+rove (rom is #bode "o is Place &f 6or /n # 4team Carriage. /t Produced # ery 6eird Noise "hat +isturbed "he orses #nd 4o /ts Bsage 6as 'imited "o # 4ingle 4treet. Richard Made # Claim "hat is /nvention ad "he Power "o Carry Near #bout ); People &n # 4ingle xpanders, (ilter Press -acs, Pulling -acs, eavy Plate ydraulic ole Punches #nd arious Einds &f 'ifting -acs.
1.&(Features+( "he jac uses compressible fluid, which is forced into a cylinder by a plunger. &il is usually used for the li!uid because it is self8lubricating and has stability compared with other li!uids. 6hen the plunger comes up, it pulls the li!uid through a chec valve suction pump. 6hen the plunger is lowered again, it sends li!uid through another valve into a cylinder. # ball used for suction in the cylinder shuts the cylinder and pressure builds up in the cylinder. "he suction valve present in the jac opens at each draw of the plunger. "he discharge valve, which is outside the jac, opens when oil is pushed into the cylinder. "he pressure of the li!uid enables the device to lift heavy loads.
1.(Classiication O )ac*+(
1..1(/echanical 0ac*+(
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www.mechengg.net Fig 1.1 /echanical 0ac*
-acscrews are integral to the 4cissor -ac, one of the simplest inds of car jacs still used. # mechanical jac is a device which lifts heavy e!uipment. "he most common form is a car jac, floor jac or garage jac which lifts vehicles so that maintenance can be performed. Car jacs usually use Mechanical advantage to allow a human to lift a vehicle by manual force alone. More powerful jacs use hydraulic power to provide more lift over greater distances. Mechanical jacs are usually rated for a maximum lifting capacity @for example, ).2 tons or tonsA. "he jac shown at the right is made for a modern vehicle and the notch fits into a hard point on a unibody. >arlier versions have a platform to lift on the vehicles% frame or axle.
1..2(!"draulic 0ac*+( ydraulic jacs are typically used for shop wor, rather than as an emergency jac to be carried with the vehicle. Bse of jacs not designed for a specific vehicle re!uires more than the usual care in selecting ground conditions, the jacing point on the vehicle, and to ensure stability when the jac is extended. ydraulic jacs are often used to lift elevators in low and medium rise buildings. # hydraulic jac uses a fluid, which is incompressible, that is forced into a cylinder by a pump plunger. &il is used since it is self lubricating and stable. 6hen the plunger pulls bac, it draws oil out of the reservoir through a suction chec valve into the pump chamber. 6hen the plunger moves forward, it pushes the oil through a discharge chec valve into the cylinder. "he suction valve ball is within the chamber and opens with each draw of the plunger. "he discharge valve ball is outside the chamber and opens when the oil is pushed into the cylinder. #t this point the suction ball within the chamber is forced shut and oil pressure builds in the cylinder. /n a bottle jac the piston is vertical and directly supports a bearing pad that contacts the object being lifted. 6ith a single action piston the lift is somewhat less than twice the collapsed height of the jac, maing it suitable only for vehicles with a relatively high clearance. (or lifting structures such as houses the hydraulic interconnection of multiple vertical jacs through valves enables the even distribution of forces while enabling close control of the lift. Page no:12
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/n a floor jac @aa %trolley jac%A a horiDontal piston pushes on the short end of a bellcran with the long arm providing the vertical motion to a lifting pad, ept horiDontal with a horiDontal linage. (loor jacs usually include castors and wheels, allowing compensation for the arc taen by the lifting pad. "his mechanism provide a low profile when collapsed, for easy maneuvering underneath the vehicle, while allowing considerable extension.
1..$( Pneu#atic 0ac*+( # pneumatic jac is a hydraulic jac that is actuated by compressed air 8 for example, air from a compressor instead of human wor. "his eliminates the need for the user to actuate the hydraulic mechanism, saving effort and potentially increasing speed. 4ometimes, such jacs are also able to be operated by the normal hydraulic actuation method, thereby retaining functionality, even if a source of compressed air is not available.
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1..$( Pneu#atic 0ac*+(
Fig 1.2 Threaded rod ull" e3tended
Fig 1.$ 2.& ton house 0ac* that stands 2% inches ro# to' to 4otto# ull" threaded out.
# house jac, also called a screw jac is a mechanical device primarily used to lift houses from their foundation. # series of jacs are used and then wood cribbing temporarily supports the structure. "his process is repeated until the desired height is reached. "he house jac can be used for jacing carrying beams that have settled or for installing new structural beams. &n the top of the jac is a cast iron circular pad that the 1F G 1F post is resting on. "his pad moves independently of the house jac so that it does not turn as the acme8 threaded rod is turned up with a metal rod. "his piece tilts very slightly but not enough to render the post dangerously out of plumb
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1..%8 Strand 0ac*+( # strand jac is a specialiDed hydraulic jac that grips steel cables often used in concert, strand jacs can lift hundreds of tons and are used in engineering and construction.
1.(5or*ing Princi'al+( "he hydraulic jac is a device used for lifting heavy loads by the application of much smaller force. /t is based on Pascal0s law, which states that intensity of pressure is transmitted e!ually in all directions through a mass of fluid at rest. "he woring principle of a hydraulic jac may be explained with the help of (ig. Consider a ram and plunger, operating in two cylinders of different diameters, which are interconnected at the bottom, through a chamber, which is filled with some li!uid.
Fig 1.% Consider a ra# and 'lunger6 1.7(5or*ing O !"draulic )ac*+( ydraulic jacs and many other technological advancements such as automobile braes and dental chairs wor on the basis of Pascal%s Principle, named for
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cylinders connected together, a small one and a large one, and apply a small (orce to the small cylinder, this would result in a given pressure.
#n enclosed fluid under pressure exerts that pressure throughout its volume and against any surface containing it. "hat%s called %Pascal%s Principle%, and allows a hydraulic lift to generate large amounts of force from the application of a small #ssume a small piston @one s!uare inch areaA applies a weight of ) lbs. to a confined hydraulic fluid. "hat provides a pressure of ) lbs. per s!uare inch throughout the fluid. /f another larger piston with an area of ); s!uare inches is in contact with the fluid, that piston will feel a force of ) lbsIs!uare inch x ); s!uare inches H ); lbs
Fig 1.& 5or*ing O !"draulic )ac*+(
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4o we can apply ) lbs. to the small piston and get ); lbs. of force to lift a heavy object with the large piston. /s this %getting something for nothing%J Bnfortunately, no. -ust as a lever provides more force near the fulcrum in exchange for more distance further away, the hydraulic lift merely converts wor @force x distanceA at the smaller piston for the 4#M> wor at the larger one. /n the example, when the smaller piston moves a distance of ); inches it displaces ); cubic inch of fluid. "hat ); cubic inch displaced at the ); s!uare inch piston moves it only ) inch, so a small force and larger distance has been exchanged for a large force through a smaller distance. ydraulic jacs have six main parts. "hese are the reservoir, pump, chec valve, main cylinder, piston, and release valve. "he reservoir holds hydraulic fluid. # pump will draw the fluid up and then create pressure on the down stroe as it pushes the fluid through the chec valve. "his valve allows the fluid to leave the reservoir and enter the main cylinder. /n the main cylinder, the piston is forced up as the cylinder is filled with the fluid. 6hen it is time to release the pressure and allow the piston to return to its starting position, the release valve is opened. "his allows the fluid to return to the reservoir.
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Sho- In Figure8(
1.9(Ad:antages+( Saet" First+( ydraulic jacing 4ystem is one of the most safest mode to erect storage tan, complete wor is executed on ground level preventing riss of accidents. (or decades, there has been not a single report that proves its credibility in being the safest and most liely method for the storage tan construction. "he Page no:1?
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hydraulic jac systems has now gained a lot of popularity.
Easier Ins'ection+(
&ur efficient hydraulic jacing systems needs various scaffolding and attachments to offer comfortable access for welding heights.
No Scaolding ;e
Faster Erection+( "he shell plates are erected at ground level in place of being installed at the height of about ; feet or more, in order to save construction time re!uired for the alignment of plates. "he time and manpower needed for lifting the plates to the height is amputated. Construction wor remains unaffected by snow or rain.
Tan* Erection To' Do-n-ards Cuts Construction Ti#e And Cost Considera4l" +( New shell plates are developed at the ground level in place of being hauled up to about ; feet heights or more, saving considerable time desired for alignment of plates. "he cumulative time needed for lifting of men and material to the heights that is eliminated. "an construction wor stays practically unaffected from rain or snow, hence most wor is performed under the protection of the tan itself.
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1.1=(A''lications+( •
+ismantling of old tans
•
Repair to tan foundation
•
•
Repair or replacement of tan bottom plate
•
/ncreasing tan capacity by adding shell rings or courses
•
>rection of other circular structures such as reactor shields in nuclear power stations, etc.
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Chapter *
+esign of ydraulic -ac
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Cha'ter 2
Design o !"draulic )ac*
2.1 !"draulic Basics+ ydraulics is the science of transmitting force andIor motion through the medium of a confined li!uid. /n a hydraulic device, power is transmitted by pushing on a confined li!uid.(igure )8) shows a simple hydraulic device. "he transfer of energy taes place because !uantity of li!uid is subject to pressure. "o operate li!uid8powered systems, the operator should have a nowledge of the basic nature of li!uids. "his chapter covers the properties of li!uids and how they act under different conditions.
2.1.1+( Pressure and Force.+( Pressure is force exerted against a specific area @force per unit areaA expressed in pounds per s!uare inch @psiA. Pressure can cause an expansion, or resistance to compression, of a fluid that is being s!ueeDed. # fluid is any li!uid or gas @vaporA. (orce is anything that tends to produce or modify @push or pullA motion and is expressed in pounds a. Pressure. #n example of pressure is the air @gasA that fills an automobile tire. #s a tire is inflated, more air is s!ueeDed into it than it can hold. "he air inside a tire resists the s!ueeDing by pushing outward on the casing of the tire. "he outward push of the air is pressure. >!ual pressure throughout a confined area is a characteristic of any pressuriDed fluid.
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ConBned li7uid is sub'e&t to pressure
Figure 2.1 Basic h"draulic de:ices
(or example, in an inflated tire, the outward push of the air is uniform throughout. /f it were not, a tire would be pushed into odd shapes because of its elasticity. "here is a major difference between a gas and a li!uid. 'i!uids are slightly compressible @(igure *.)A. 6hen a confined li!uid is pushed on, pressure builds up. "he pressure is still transmitted e!ually throughout the container. "he fluid%s behavior maes it possible to transmit a push through pipes, around corners, and up and down.
+*H()K+)I(* 6here () H force of the small piston, in pounds +) H distance the small piston moves, in inches +* H distance the larger piston moves, in inches (* H force of the larger piston, in pounds
2.2(Basic S"ste#s+( Page no:23
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"he advantages of hydraulic systems over other methods of power transmission are L 4impler design. /n most cases, a few pre8engineered components will replace complicated mechanical linages. L (lexibility. ydraulic components can be located with considerable flexibility. Pipes and hoses in place of mechanical elements virtually eliminate location problems. L 4moothness. ydraulic systems are smooth and !uiet in operation. ibration is ept to a minimum. L Control. Control of a wide range of speed and forces is easily possible. L Cost. igh efficiency with minimum friction loss eeps the cost of a power transmission at a minimum. L &verload protection. #utomatic valves guard the system against a breadown from overloading. "he main disadvantage of a hydraulic system is maintaining the precision parts when they are exposed to bad climates and dirty atmospheres. Protection against rust, corrosion, dirt, oil deterioration, and other adverse environment is very important. "he following paragraphs discuss several basic hydraulic systems.
A8 !"draulic )ac*+( /n this system a reservoir and a system of valves has been added to Pascal%s hydraulic lever to stroe a small cylinder or pump continuously and raise a large piston or an actuator a notch with each stroe. +iagram # shows an intae stroe. #n outlet chec valve closes by pressure under a load, and an inlet chec valve opens so that li!uid from the reservoir fills the pumping chamber. +iagram < shows the pump stroing downward. #n inlet chec valve closes by pressure and an outlet valve opens. More li!uid is pumped under a large piston to raise it. "o lower a load, a third valve @needle valveA opens, which opens an area under a large piston to the reservoir. "he load then pushes the piston down and forces the li!uid into the reservoir.
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Figure 2(2. !"draulic 0ac*
B8 /otor(;e:ersing S"ste#+( (igure *8*, shows a power8driven pump operating a reversible rotary motor. # reversing valve directs fluid to either side of the motor and bac to the reservoir. # relief valve protects the system against excess pressure and can bypass pump output to the reservoir, if pressure rises too high.
C8O'en(Center S"ste#+( /n this system, a control8valve spool must be open in the center to allow pump flow to pass through the valve and return to the reservoir. Page no:2<
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this system in the neutral position. "o operate several functions simultaneously, an open8center system must have the correct connections, which are discussed below. #n open8center system is efficient on single functions but is limited with multiple functions. "he return from the first valve is routed to the inlet of the second, and so on. /n neutral, the oil passes through the valves in series and returns to the reservoir, as the arrows indicate. 6hen a control valve is operated, the incoming oil is diverted to the cylinder that the valve serves. Return li!uid from the cylinder is directed through the return line and on to the next valve. "his system is satisfactory as long as only one valve is operating at a time. 6hen this happens, the full output of the pump at full system pressure is available to that function. owever, if more than one valve is operating, the total of the pressures re!uired for each function cannot exceed the system0s relief setting.
2.$(Parts O !"draulic )ac*+(
?land @>nd CapA Piston Road Cylinder
2.$.1(Parts O C"linder+( 2.$.1.1(C"linder Barrel+( "he cylinder barrel is mostly a seamless thic walled forged pipe that must be machined internally. "he cylinder barrel is ground andIor honed internally.
2.$.1.2(C"linder Base Or Ca'+( /n most hydraulic cylinders, the barrel and the bottom portion are welded together. "his can damage the inside of the barrel if done poorly. "herefore, some cylinder designs have a screwed or flanged connection from the cylinder end cap to the barrel. /n this type the barrel can be disassembled and repaired. Page no:2=
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2.$.1.$(C"linder !ead+( "he cylinder head is sometimes connected to the barrel with a sort of a simple loc. /n general, however, the connection is screwed or flanged. (lange connections are the best, but also the most expensive. # flange has to be welded to the pipe before machining. "he advantage is that the connection is bolted and always simple to remove. (or larger cylinder siDes, the disconnection of a screw with a diameter of ;; to 3;; mm is a huge problem as well as the alignment during mounting.
2.$.2(Piston ;od+( "he piston rod is typically a hard chrome8plated piece of cold8 rolled steel which attaches to the piston and extends from the cylinder through the rod8end head. /n double rod8end cylinders, the actuator has a rod extending from both sides of the piston and out both ends of the barrel. "he piston rod connects the hydraulic actuator to the machine component doing the wor. "his connection can be in the form of a machine thread or a mounting attachment, such as a rod8clevis or rod8eye. "hese mounting attachments can be threaded or welded to the piston rod or, in some cases, they are a machined part of the rod8end.
2.$.2.1+(Piston ;od Construction+( "he piston rod of an hydraulic cylinder operates both inside and outside the barrel, and conse!uently both in and out of the hydraulic fluid and surrounding atmosphere. 2.$.2.1.1+(/etallic Coatings+(
4mooth and hard surfaces are desirable on the outer diameter of the piston rod and slide rings for proper sealing. Corrosion resistance is also advantageous. # chromium layer may often be applied on the outer surfaces of these parts. owever, chromium layers may be porous, thereby attracting moisture and eventually causing oxidation. /n harsh marine environments, the steel is often treated with both a nicel layer and a chromium layer. &ften 1; to )2; micrometer thic layers are applied. 4ometimes solid stainless steel rods are used. igh !uality stainless steel such as #/4/ )3 may be used for low stress applications. &ther stainless steels such as #/4/ 1) may also be used where there are higher stresses, but lower corrosion concerns. Page no:2>
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2.$.2.1.2+(Cera#ic Coatings+(
+ue to shortcomings of metallic materials, ceramic coatings were developed. /nitially ceramic protection schemes seemed ideal, but porosity was higher than projected. Recently the corrosion resistant semi ceramic 'unac* coatings were introduced. "hese hard coatings are non porous and do not suffer from high brittleness. 2.$.2.1.$+(Length+(
Piston rods are generally available in lengths which are cut to suit the application. #s the common rods have a soft or mild steel core, their ends can be welded or machined for a screw thread.
2.$.2.$+(>land ?End Ca'@+( "he cylinder head is fitted with seals to prevent the pressuriDed oil from leaing past the interface between the rod and the head. "his area is called the rod gland. /t often has another seal called a rod wiper which prevents contaminants from entering the cylinder when the extended rod retracts bac into the cylinder. "he rod gland also has a rod wear ring. "his wear ring acts as a liner bearing to support the weight of the piston rod and guides it as it passes bac and forth through the rod gland. /n some cases, especially in small hydraulic cylinders, the rod gland and the rod wear ring are made from a single integral machined part.
C*apter 3 Page no:2?
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Cal&ulation 9or design Page no:2@
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CALCLATIONS+( +istance the larger piston moves +*H()K+)I(* 6here () H force of the small piston, in pounds +) H distance the small piston moves, in inches +* H distance the larger piston moves, in inches (* H force of the larger piston, in pounds
"he definition of fluid pressure is a force per unit area, or in e!uation form, PH(I A where P H pressure @NIm*, psiA, ( H force @N, lbf A, and # H area @m*, in*A.
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T) %#ND #NNE" D#*METE" )% C+,#NDE" TU-E:'
p
here P 0 total press$re D 0 #nner diameter p 0 or1ing press$re
2 34555 0 5.678 9 D 9 255
02555/5.6783255
D
D
0 4.6;
0 ;CM 0 ;5MM.
T) %#ND )UTE" D#*METE" )% C+,#NDE" TU-E:'
?e have already a e@$ation 0 ?here
0 or1ing stress P 0 or1ing press$re
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0 o$ter diameter of cylinder t$=e 0 inner diameter of cylinder t$=e 0 ?or1ing stress 0 A55/A0 4585 B&/CM
1050 = 300 ×
1A?AAAA3AAdo D1A?AAAA >AAAAA do 2>AAAAAE>3mm
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Chapter 1
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/f the word hydraulics is understood to mean the use of water for the benefit of manind, then its practice must be considered to be even older than recorded history itself. "races of irrigation canals from prehistoric times still exist in >gypt and Mesopotamia$ the Nile is nown to have been dammed at Memphis some six thousand years ago to provide the necessary water supply, and the >uphrates River was diverted into the "igris even earlier for the same purpose. #ncient wells still in existence reach to surprisingly great depths$ and underground a!ueducts were bored considerable distances, even through bedroc. /n what is now Paistan, houses were provided with ceramic conduits for water supply and drainage some five thousand years ago$ and legend tells of vast flood8control projects in China barely a millenium later. #ll of this clearly demonstrates that men must have begun to deal with the flow of water countless millenia before these times. "hough both the art and the science of hydraulics treat of such flows, they obviously differ significantly in time and substance. ydraulic practice necessarily originated as an art, for the principles involved could be formulated only after long experience with science in general and water in particular. owever necessary the conduct of the art thus was to the eventual development of the science, it is almost exclusively with the science of hydraulics that the present article will deal. #s a matter of fact, the subiect matter of the traditional college course in hydraulics 88 particularly as it was taught in the not8too8recent past 88 provides a framewor on which the history of the science can conveniently be based. 4uch a course usually began with the topic of hydrostatics 88 the characteristics of li!uids at rest. /nstructors then proceeded to the principle of continuity @the conservation of fluid massA and a form of the wor8energy principle nown as the
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fact that many such principles were first clarified by men lie /saac Newton whose interests extended far beyond hydraulics itself. "his scienceactually had its origins some two millenia ago in the course of ?ree civiliDation. /t must be granted, however, that ?ree physics was of such a hypothetical nature that with one exception it had little positive influence in the millenia to follow. "he part that concerns us here is the then8prevailing belief that the universe consists of four elements @fire, air, water, and earthA, that each is displaced by the next in order of increasing weight, and that the space around us must be occupied by one element or another. FNature,F in other words, Fabhors a vacuum.F /n due time the concept of a fifth element, ether, came into being, for want of something to fill outer space. "o the ?rees, the abhorrence of a vacuum served to explain free flight, a body in motion presumedly being driven by the fluid closing in behind. Enown as the medium theory of motion, this was one of the teachings of #ristotle @918** <.C.A, who wrote on a wide variety of subjects ranging from physics to metaphysics. "he so8called impetus theory of motion was proposed nearly a thousand years after #ristotle%s time$ however, because impetus could not be seen, the concept was not generally accepted, and the medium theory remained in favor for at least another millenium. "he ?reewho made the most lasting contribution to hydraulics was the 4icilian mathematician #rchimedes @*958*)* <.C.A, who reasoned that a floating or immersed body must be acted upon an upward force e!ual to the weight of the li!uid that it displaces. "his is the basis of hydrostatics and also of the apocryphal story that #rchimedes made this discovery in his bath and forthwith ran un clothed through the streets crying F>ureaF Nevertheless, even though #rchimedes% writings, lie those of his fellow ?rees, were faithfully transmitted to the 6est by #rabian scientists, further progress in hydrostatics was not to be made for another )9 centuries. /n the course of the millenium following the time of #rchimedes, the science of hydraulics retrogressed rather than advaneed. "rue, though the Romans developed extensive water8supply and drainage systems, and windmills and water wheels appeared on the scene in increasing numbers, these represented the art rather than the science. Paradoxically, although #ristotle taught that nowledge Page no:3=
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must progress, his teachings eventually came to be crystalliDed, so to spea, and in the time of 4aint "homas #!uinas @)**2851A, they were even adopted as gospel truth by the church. /n the same period, on the other hand, researchers in the early universities particularly Paris, &xford, and Cambridge gradually began to establish simple mechanical relationships such as that between velocity and acceleration. 6hereas the ?rees tended to reason without recourse to observation, it was the /talian genius 'eonardo da inci @)12*8)2):A who first emphasiDed the direct study of nature in its many aspects. 'eonardo%s hydraulic observations extended to the detailed characteristics of jets, waves, aud eddies, not to mention the flight of birds and comparable facets of essential/y every other field of nowledge. /n particular, it was 'eonardo who first correctly formulated the basic principle of hvdraulics nown as continuity7 the velocity of flow varies inversely with the cross8sectional area of a stream. Bnfortunately, not only were his copious notes writteu in mirror image @probably for reasons of secrecyA, but, in addition, most of them were lost for several centuries after his death. "hus his discoveries had little effect on the growth of the science. "he second essential coutribution to hydrostatics was made by the +utch hydraulic engineer 4imon 4tevin @)2198)3*;A in )293, nearly two millenia after the time of #rchimedes. 4tevin showed that the force exerted by a li!uid on the base of a vessel is e!ual to the weight of a li!uid column extending from the base to the free surface. "hat this force does not depend on the shape of the vessel became nown as the hydrostatic paradox. /f 'eonardo was the first scientific observer of note, it was ?alileo @)2318)31*A who added experimentation to observation, thereby throwing initial light on the problem of gravitational acceleration. /n his study of the phenomenon, he noted that a body sliding freely down an inclined plane attained a certain speed after a certain vertical descent regardless of the slope$ it is said that he hence advised an engineer that there was no point in eliminating river bends, as the resulting increase in slope would have no effect 6hereas 'eonardo was a loner, ?allleo gathered a small school around him. &ne of his students, the #bbe
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younger colleague >vangelista "orricelli @)3;9815A applied his mentor%s analysis of parabolic free8fall trajectories to the geometry of li!uid jets. "orricelli also experimented with the li!uid barometer, the vacuum above the li!uid column being comparable to the void that ?alileo found to develop in a pump whose suction pipe exceeded a certain length$ in other words, nature abhorred a vacuum only up to a certain point "he (rench scientist >dme Mariotte @)3*;891A is often called the father of (rench hydraulics because of the breadth of his experimentation$ this included such matters as wind and water pressure and the elasticity of the air, a !uality which we usually associate with the name of the >nglishman Robert nglish contemporary /saac Newton @)31*8)5*5A, who correctly used the principle of momentum to evaluate the orbits, held that if there were vortex material in space, the motion of the planets would be retarded. Newton Page no:3?
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even conducted a variety of experiments on the resistance @due to fluid tenacity, elasticity, want of lubricity, and inertiaA encountered by bodies in motion to prove that nothing of the sort occurred in space. /n the course of these studies, he formulated the speed of sound in air @except for the adiabatic constantA, the basis of viscous shear, and the e!uation of what we now call form drag @except that he mistaenly considered shape itself to be of no importanceA. e also invented what he termed the theory of fluxions, now nown as the calculus. Newton%s ?erman contemporary ?ottfried 6ilhelm von 'eibniD @)3138)5)3A conceived the principle of energy, though without the fraction one8 half in the inetic8energy term, and as a result his principle gave different results from Newton%s momentum principle when used to describe the same phenomenon. 'eibniD also developed a form of the calculus, and his colleagues and Newton%s soon began to accuse the other of plagiarism, a dispute which, though largely unjustified, produced a considerable rift between the >nglish and the ?erman scientists. &ne of the earliest mathematicians to apply 'eibniD%s calculus @and even to contribute some of the nomenclature still used todayA was the 4wiss -ohann uler @)5;589A. -ohann thereafter went to Paris to collaborate with the (rench nobleman the Mar!uis de l%opital$ +aniel became a member of the Russian academy at 4t. Petersburg, where he was later joined bv >uler. '%opital eventually published his and -ohann%s @largely the latter%sA joint findings without due credit to his collaborator, much to -ohann%s chagrin. 6hen +aniel published in )59 the original treatise ydrodynamica, -ohann proceeded to write a boo that he called ydraulica, which 88 whether through envy or bitterness over l%opital%s failure to acnowledge his contribution 88 he purposely predated a full ten years +aniel%s wor contained much that was new for example, the use of manometers, the inetic theory of gases, and iet propulsion but nowhere in the boo @or in his father%s eitherA can one find what is nown as the
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and inetic terms, so too did the uler, an outstanding mathematician, from his e!uations of acceleration for the conditions of steady, irrotational flow under gravitational action. >uler also deserved credit for a number of e!uations of hydraulics and for inventing at least on paper a worable hydraulic turbine. 6orthy of mention in the same breath as >uler and the ven (ranlin was not the first to conduct scale8model tests, credit for which is due -ohn 4meaton @)5*18:*A, an >nglish engineer who was one of the very few practical people in his country to become a member of the Royal 4ociety in the course of the next century or so. /n his priDe8winning paper of )52:, F#n experimental /n!uiry concerning the Natural Powers of 6ater and 6ind to turn Mills, and other Machines, depending on a Circular MotionF, 4meaton described experiments on models of undershot wheels, overshot wheels, and windmills, evaluating there from the general power relationships. "wo essential measuring instruments came into being at this time, the Pitot tube and the rotating arm. "he first still bears the name of its inventor, the (renchman enri de Pitot @)3:28)55)A, who called it a FmachineF for determining the speed of flowing water. /t consisted of two vertical glass tubes connected at their top by a valve, one tube simply being open at the bottom and the other '8 shaped with its open end pointing upstream$ the difference in water level between the two tubes after closure of the valve and their withdrawal from the flow permitted the velocity to be computed. Bse of a rotating arm to propel a body
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through air for its drag determination was developed bv the >nglishman nglish made notable contributions in the course of the eighteenth and nineteenth centuries, the leadership was definitely (rench, mainly through the influence of the Corps des Ponts et Chaussees, which had been functioning effectively since its founding in )5):. (or example, in )9** 'ouis Marie enri Navier @)5928)93A, a bridge engineer, was the first to attempt the extension of the >uler e!uations of acceleration to include the flow of a viscous fluid. "hough he did not comprehend the essential mechanism of viscous action, his results were mathematically correct. "he same e!uations were developed with groater comprehension somewhat later by the mathematician
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not only to the laminar phase of viscous flow bnt also to that nown as fluid turbulence /n the first half of the nineteenth century, the ?erman ?otthilf 'udwig agen @)5:58)991A condncted in )9: some very meticu lous measurements of the flow of water in small8diameter tubes, utiliDing the water temperature instead of the viscosity as one of the parameters. # few years later the (rench physician -ean 'ouis Poiseuille @)5::8)93:A repeated the experiments independently using even liner tubes to simulate blood vessels, and oil and mercury in addition to water. >xcept in ?ermany, the phenomenon is nown as Poiseuille flow, even though neither Poiseuille nor agen really understood the mathematics of the phenomenon. agen, however, had remared in an )921 paper that the flow was not always laminar, the efflux jet sometimes being clear and sometimes frosty$ similarly, sawdust suspended in the water sometimes moved in straight lines and sometimes very irregularly$ in the latter instances he noted that his resistance e!uation no longer applied. "hough countless contributors to hydraulic science of this period are to be found in the ever8growing literature, only a few can be mentioned at this point. "hese include the /talian ?iovanni ytelwein @)5318)919A and -ulius 6eisbach @)9;385)A./n addition to nglishmen who lived in the latter part of the last century. &ne was the Manchester professor &sborne Reynolds @)91*8):)*A, who in )95 also experimented with flow through tubes, introducing the viscosity to form a parameter maring the borderline between laminar and turbulent flow. now nown as the Reynolds number. Reynolds also showed bv the injection of dye the difference be tween the two states of motion, for which he is given the credit really due agen for his wor *; years earlier. 6illiam (roude @)9);85:A was a somewhat older contemporary of Reynolds whose interests lay in the field of naval architecture. (roude built himself a towing tan on his own property and in part with his own funds, for the operation of which he had formulated a similarity law for flows under the influence of gravity. "his law has come to be nown under (roude%s name, although it had actually been Page no:2
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announced at least *; years earlier by (erdinand Reech @)9;2 9;A, an #lsatian teaching in a naval college at Paris. uler and d%#lembert, the practice was continued by such e!ually famous men as 'agrange @)538)9)A, 'aplace @)51:8)9*5A, elmholtD @)9*)8:1A, Eelvin @)9*18):;5A, and Rayleigh @)91*8):):A, as recorded in the many editions of the treatise ydrodymimic by the Manchester professor orace 'amb @)91:8):1A. owever, although presumably dealing with the same fluids, the two subjects were far apart, for hydraulics still laced mathematical rigor, and hydrodynamics, sufficient contact with reality. "hus, when human flight became a lielihood, neither hydraulics nor hydrodynamics could provide a useful scientific basis for the understanding of aerodynamic lift if not of drag. (ortunately, a new science, the mechanics of fluids, came into being at the hands of 'udwig Prandtl @)9528):2A, a ?erman mechanical engineer teaching at the Bniversity of ?ottingen. e reasoned as early as ):;1 that relative motion between a fluid and a streamlined boundary could be analyDed in two parts7 a thin layer at the boundary providing the viscous resistance to motion, and the fluid outside the boundary layer providing, in accordance with the principles of irrotational flow, the normal forces producing lift. Prandtl, and the many students who passed through his hands, proceeded to formulate the essential principles of airfoil and propeller operation. #t the same time, the general principles of fluid mechanics became the basis of related fields, including hydraulics. /n fact, Paul Richard einrich
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Niuradse @)9:18):5:A experimented extensively on the resistance of rough pipes as well as smooth. >xcept for uropeans. #s recounted elsewhere , #merican hydraulicians gradually became aware of >nglish, (rench, and eventually ?erman discoveries, utiliDing their coefficients and later repeating and extending their experiments. urope under (reeman%s auspices were in positions of responsibility. "heir experiments ranged from torpedo cavitation to ship drag, from the diffusion of smoe and gas by wind to fog dispersal over airplane landing fields, from the throw of fire streams to atmospheric turbulence. (reeman%s indirectrole in advancing the science in #merica was directly abetted by the influence of two naturaliDed immigrants, ngineering 4ocieties Monograph Page no:
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an extended translation of his 4t. Petersburg dissertation on open8channel flow. # native ungarian, von Earmfin was one of Prandtl%s earliest doctoral students and later a very productive professor at #achen, ?ermany$ with the rise of itler, he migrated to Cal "eeh at Pasadena, and then to 6ashington as air force consultant during the war$ he was the first to receive from President Eennedy the new National Medal of 4cience, and his autobiography "he 6ind and nd of the >ighteenth Century.F 'ater that year / received an appointment as (ulbright research scholar at ?renoble, (rance, where Pierre +anel, director of the hydraulics laboratory at the >tablissements Neyrpic, had developed a magnificent library that included many of the historical wors mentioned herein. 6ith such material at hand, / rewrote and greatly expanded /nce%s dissertation, bringing it up to the middle of the present century. "his was published as a bilingual supplement to 'a ouille ssentially all of the boos cited in these pages are included therein. /n fact, some 2; individual items are now at hand the finest collection that / now to exist on the history of hydraulics.
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Chapter 2
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;E FE;ENCES
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are t*e sour&es 7uoted or parap*rased in t*is publi&ation. 4onmilitary Publi&ations ydrauli&s. eere and Company ervi&e Publi&ations% Moline% Illinois. 1@@>. Industrial ydrauli&s Manual. Fi&ers "raining Center% -o&*ester ills% Mi&*igan. 1@@3. 0C5M#4" 4### "*ese do&uments must be available to t*e users o$ t*is publi&ationG epartment o$ t*e !rmy 9orms ! 9orm 2A2?. -e&ommended C*anges to Publi&ations and lan 9orms. 9ebruary 1@>
*ttp:HH.mar&ur.&omHydrauli&s2APd$H?A+??2Aydrauli&2A;a&s
2AMar&ur2Aydrauli&s.pd$ *ttp:HH.deri'&e.&omHdlHmanual.pd$ *ttp:HH.google.&o.inHJ7*ydrauli&D'a&Dpd$DBle6*len6sa$ea&tive6pr mdimvns6eigK#">7sM$,rKeIa3K6start2A6sa46bavon.2%or.r g&.rp.%&$.osb6$pA$A$A&@>1<@=26bi11<26bi*>>36sa$ea&tive
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