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Hydraulics 2 pdf

Hydraulics is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids or fluids. At a very basic level, hydraulics is the liquid version of pneumatics. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the applied engineering using the properties of fluids.

In fluid power, hydraulics are used for the generation, control, and transmission of power by the use of pressurized liquids. Hydraulic topics range through some parts of science and most of engineering modules, and cover concepts such as pipe flow, dam design, fluidics and fluid control circuitry, pumps.

The principles of hydraulics are in use naturally in the human body within the heart and the male erection. Free surface hydraulics is the branch of hydraulics dealing with free surface flow, such as occurring in rivers, canals, lakes, estuaries and seas. Its sub-field open channel flow studies the flow in open channels.

Hydraulics Lectures and Class Notes Free Download Hydraulics is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids or fluids.

Solved ProblemsHydraulics. Open Channel Hydraulics V. T Chow Solved Example 02 Q. The temperature of the water is taken as F. DefinitionFluid MechanicsTypes ofHydraulics. Turbine - Definition and Types of Turbines It is a device which converts mechanical energy into electrical energy or hydraulic energy into electrical energy.

Turbines can also be termed as machines extracting energy from fluids. Water driven tubes are used primarily for the development of hydro-electric energy. There can be two basic types of hydraulic turbines. In impulse turbines a free jet of water strikes the. To Calibrate a Pressure Gauge Using a Dead Weight Pressure Gauge Calibrator A length of tube was connected to the calibrator drain and laid into the channel to prevent spillage of water on the bench top.

The calibrator was leveled by the adjusting feel whilst observing the spirit level. DefinitionFactors AffectingHydraulics. This effect can be produced in any fluid. When a flow is stopped backwater effect is produced in which a wave of water moves against the flowing water. It is caused by a pressure or a. ExperimentsLab-NotesHydraulics. Experimental study of Laminar, Transitional and Turbulent Flow The type of flow in which the particles move in a straight line in the form of a thin parallel sheets is known as the Laminar flow.

Laminar flow denotes a steady condition where all stream lines follow parallel paths. Under this condition, the dye. In engineering practice, the hydraulic jump frequently appears downstream from overflow structures spillwaysor under flow structures sluice gateswhere velocities are height. A hydraulic jump is formed when liquid at high velocity discharges into. Experiment - Various Parts of Hydraulic Bench Hydraulic bench is a very useful apparatus in hydraulics and fluid mechanics.

It is involved in majority of experiments to be conducted e.Where to Buy Shop Contact. Learn More. Hydraulics Performance Under Any Pressure We have the right filters, contamination control products and capabilities to protect machinery and components in hundreds of applications — in the factory and on heavy-duty equipment. When you need hydraulic filtration, turn to Donaldson.

Table of Contents. Products Your selection did not return any results. Please reset and try a new selection. Replacement Filters We offer a complete line of filters and cartridges for low, medium and high pressure applications. Each is also available in a range of media efficiencies to meet specific application requirements. Assemblies Offering a complete line of low, medium and high-pressure assemblies for use throughout hydraulic circuits.

Accessories Accessories for hydraulic circuits, lines and reservoirs help you maintain proper ISO cleanliness levels. Fluid Analysis Fluid analysis is a snapshot of what's happening inside your equipment. It summarizes the condition of your oil and identifies component wear and contamination in virtually any application. Off-Line Filtration Offline oil filtration systems offer convenient filtration, flushing and fluid transfer for added system cleanliness and acute system clean-up.

Looking for more? Find filters and parts directly online. Shop Now. Have more questions about how our products benefit your business? Contact Us.To browse Academia. Skip to main content. Log In Sign Up. Ahmed Mohamed. Unsteady flow in pipes 1. Water hammer 2. Slow closure: unsteady incompressible pipe flow 3.

Unsteady Flow in Pipes 1. If this were all to be brought to rest simultaneously by the rapid closure of a valve then the pressure rise would be enormous. Such large pressure transients can lead to severe pipe or valve damage, so should be designed against.

Means of achieving a more gradual change in velocity are discussed in Section 3. However, large pressure transients can sometimes be useful. In the ram pump or hydraulic ram the periodic closure of a valve by a relatively low-head flow creates short bursts of high pressure which can deliver water to a much greater height albeit it at a smaller mean flow rate.

Since the device requires only a steady flow of water and not a power supply it is very useful for raising water in remote regions. For incompressible flow all the fluid in the pipe is moving at the same speed u. Moreover, since the velocity is the same anywhere in the pipe, the difference in piezometric head is the same as the difference in total head. For slow changes of velocity, pressure changes are small enough for the incompressible approximation to remain valid, and this equation can be solved to give u as a function of time.

This is the slow-closure problem which will be used to analyse surge tanks and pressure-relief valves in Section 3. In this rapid-closure problem the pressure transient is huge, the incompressibility assumption breaks down and elastic properties of the fluid and the pipe must be considered.

The whole of the fluid in the pipe does not respond to the valve closure simultaneously; instead, a pressure discontinuity shock propagates back along the pipe: the phenomenon of water hammer. Water Hammer The near-instantaneous stopping of all the water in a long pipeline can only be brought about by huge pressures.

In practice, the fluid adjacent to the valve is compressed and a positive pressure pulse propagates back along the pipe at speed c rather akin to the build-up of cars in a motorway pile-up. The propagating front is referred to as a shock, and the phenomenon in pipelines as water hammer. Although the phenomenon is most often associated with valve closure, large negative pressure pulses may occur if the valve is opened rapidly, and may lead to cavitation, which should be avoided at all costs.

Consider a discontinuity propagating at speed c the celerity to the left in response to a valve closure. In front of it is fluid with velocity u which as yet has not felt the effect of the closure. In the first instance we assume that the pipe is rigid — i.

hydraulics 2 pdf

This is effectively the speed of sound in the fluid.The basic idea behind any hydraulic system is very simple: Force that is applied at one point is transmitted to another point using an incompressible fluid. The fluid is almost always an oil of some sort. The force is almost always multiplied in the process. The picture below shows the simplest possible hydraulic system:. A Simple hydraulic system consisting of two pistons and an oil-filled pipe connecting them. Click on the red arrow to see the animation.

In this drawing, two pistons red fit into two glass cylinders filled with oil light blue and connected to one another with an oil-filled pipe. If you apply a downward force to one piston the left one in this drawingthen the force is transmitted to the second piston through the oil in the pipe. Since oil is incompressible, the efficiency is very good -- almost all of the applied force appears at the second piston. The great thing about hydraulic systems is that the pipe connecting the two cylinders can be any length and shape, allowing it to snake through all sorts of things separating the two pistons.

The pipe can also fork, so that one master cylinder can drive more than one slave cylinder if desired. The neat thing about hydraulic systems is that it is very easy to add force multiplication or division to the system. If you have read How a Block and Tackle Works or How Gears Workthen you know that trading force for distance is very common in mechanical systems.

Hydraulics Lectures and Class Notes Free Download

In a hydraulic system, all you do is change the size of one piston and cylinder relative to the other, as shown here:. Hydraulic multiplication. The piston on the right has a surface area nine times greater than the piston on the left. When force is applied to the left piston, it will move nine units for every one unit that the right piston moves, and the force is multiplied by nine on the right-hand piston.

Click the red arrow to see the animation. To determine the multiplication factorstart by looking at the size of the pistons. Assume that the piston on the left is 2 inches in diameter 1-inch radiuswhile the piston on the right is 6 inches in diameter 3-inch radius. The area of the left piston is therefore 3.Hydraulicsbranch of science concerned with the practical applications of fluids, primarily liquids, in motion.

It is related to fluid mechanics q. Hydraulics deals with such matters as the flow of liquids in pipes, rivers, and channels and their confinement by dams and tanks. Some of its principles apply also to gases, usually in cases in which variations in density are relatively small.

Consequently, the scope of hydraulics extends to such mechanical devices as fans and gas turbines and to pneumatic control systems. Liquids in motion or under pressure did useful work for man for many centuries before French scientist-philosopher Blaise Pascal and Swiss physicist Daniel Bernoulli formulated the laws on which modern hydraulic-power technology is based. Thus, velocity energy, deriving from motion, can be partly converted to pressure energy by enlarging the cross section of a pipe, which slows down the flow but increases the area against which the fluid is pressing.

Until the 19th century it was not possible to develop velocities and pressures much greater than those provided by nature, but the invention of pumps brought a vast potential for application of the discoveries of Pascal and Bernoulli. In the city of London built a hydraulic system that delivered pressurized water through street mains to drive machinery in factories. In hydraulic-power systems there are five elements: the driver, the pump, the control valves, the motor, and the load.

The driver may be an electric motor or an engine of any type. The pump acts mainly to increase pressure.

The motor may be a counterpart of the pump, transforming hydraulic input into mechanical output. Motors may produce either rotary or reciprocating motion in the load.

The growth of fluid-power technology since World War II has been phenomenal. In the operation and control of machine tools, farm machineryconstruction machinery, and mining machinery, fluid power can compete successfully with mechanical and electrical systems see fluidics. Its chief advantages are flexibility and the ability to multiply forces efficiently; it also provides fast and accurate response to controls.

Fluid power can provide a force of a few ounces or one of thousands of tons. Hydraulic-power systems have become one of the major energy-transmission technologies utilized by all phases of industrial, agricultural, and defense activity. Modern aircraft, for example, use hydraulic systems to activate their controls and to operate landing gears and brakes. Virtually all missiles, as well as their ground-support equipment, utilize fluid power.


Automobiles use hydraulic-power systems in their transmissions, brakes, and steering mechanisms. Mass production and its offspring, automation, in many industries have their foundations in the utilization of fluid-power systems. Info Print Cite. Submit Feedback. Thank you for your feedback. Hydraulics fluid mechanics. See Article History. Get exclusive access to content from our First Edition with your subscription. Subscribe today.

hydraulics 2 pdf

Learn More in these related Britannica articles:. Fluidicsthe technology of using the flow characteristics of liquid or gas to operate a control system. One of the newest of the control technologies, fluidics has in recent years come to compete with mechanical and electrical systems. Although fluidic principles are fairly old, it was not until about that….

The earliest pumps were devices for raising water, such as the Persian and Roman waterwheels and the more sophisticated Archimedes screw q.For full functionality of this site it is necessary to enable JavaScript.

Here are the instructions how to enable JavaScript in your web browser. The basis for all hydraulic systems is expressed by Pascal's law which states that the pressure exerted anywhere upon an enclosed liquid is transmitted undiminished, in all directions, to the interior of the container.

This principle allows large forces to be generated with relatively little effort. As illustrated, a 5 pound force exerted against a 1 inch square area creates an internal pressure of 5 psi. This pressure, acting against the 10 square inch area develops 50 pounds of force.

In a basic hydraulic circuit, the force exerted by a cylinder is dependent upon the cylinder bore size and the pump pressure. There is no force generated unless there is resistance to the movement of the piston. With psi pump pressure exerted against a 12 square inch piston area approximately 4" dia. The speed at which the piston will move is dependent upon the flow rate gpm from the pump and the cylinder area.

Hence, if pump delivery is 1 gallon per minute cu. The simplest hydraulic circuit consists of a reservoir, pump, relief valve, 3-way directional control valve, single acting cylinder, connectors and lines. This system is used where the cylinder piston is returned by mechanical force.

With the control valve in neutral, pump flow passes through the valve and back to the reservoir. With the valve shifted, oil is directed to the piston side of the cylinder, causing the piston to move, extending the rod. If the valve is returned to neutralthe oil is trapped in the cylinder, holding it in a fixed positionwhile pump flow is returned to the reservoir.

Shifting the valve in the opposite direction permits the oil to pass through the valve back to the reservoir. The relief valve limits the system pressure to a pre-set amount. Relief valves are commonly incorporated into the directional control valve. A hydraulic system using a double acting cylinder and a 4-way valve differs from the single acting cylinder system in that the cylinder can exert force in both directions.

With the control valve in, neutral flow is returned to the reservoir. When shifted in one directionoil is directed to the piston side of the cylinder, causing the cylinder to extend. Oil from the rod side passes through the valve back to the reservoir. If the valve is shifted to neutraloil in the cylinder is trapped, holding it in a fixed position. When the valve is shifted in the opposite position, oil is directed to the rod side of the cylinder, causing the cylinder to retract.

Fluid Mechanics - Open Channel Flow - Lecture 1

Oil from the piston side passes through the valve back to the reservoir. Cylinder extend force is the result of the pressure psi times the piston area minus any force resulting from the pressure acting against the rod side of the piston.

Retract force is a result of the pressure psi times the area difference between the rod and the piston minus any force resulting from pressure acting against the piston side of the cylinder.


Rotary hydraulic motor circuits are basically the same as cylinder circuits. Systems may be uni-directional or bi-directional as shown. The amount of rotary force torque available from the motor is a function of pressure psi and motor size.

hydraulics 2 pdf

Speed is a function of flow and motor size. All of the systems described above are open center systems due to the oil flowing through the control valve back to the tank. Most systems are this type.New approaches to thinking and design make hydraulic power units the key components in the efficient and intelligent factory of the future. Currently we avoid - even if it is very difficult for us - personal contacts. Nevertheless, you do not have to cancel or postpone appointments with our sales staff.

Our employees are perfectly equipped to conduct meetings with you via Skype instead of an on-site appointment - virtually from home office to home office. If you would like to use the coming weeks to refresh and extend your knowledge of hydraulics or to find out about our latest products, we have something for you too!

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