Hydraulic Fluid Mechanics
Hydraulics is the branch of science that deals with the practical applications of fluids, especially fluids in motion. It is largely related to fluid mechanics, which provides its theoretical basis. Hydraulics deals with issues such as the flow of liquids in pipes, rivers and canals and their confinement by dams and tanks. Some of its principles also apply to gases, usually where changes in density are relatively small. As a result, the scope of hydraulics extends to mechanical devices such as fans and gas turbines, as well as pneumatic control systems.
What is hydraulics?
Hydraulics is a mechanical function that works with the force of fluid pressure.
In hydraulic-based systems, mechanical motion is produced by pumped fluid, typically maintained through hydraulic cylinders that move pistons.
Hydraulics is a component of mechatronics, which combines mechanical, electronic and software engineering to design and manufacture products and processes.
Who invented hydraulics?
It is difficult to determine exactly who invented hydraulics. However, traces of the use of hydraulic-based systems can be traced back to the 1st century.
French physicist, mathematician, inventor, philosopher and theologian Blaise Pascal made notable achievements in the fields of hydrostatics and hydrodynamics and is known for the invention of the first hydraulic press to use hydraulic pressure to multiply forces.
Additionally, he invented Pascal's law, or Pascal's principle of hydrostatics, which states that a liquid at rest in a closed container can cause a high change of pressure in every part of the liquid and on the walls of the container without loss.
How do hydraulic systems work?
Today's systems include hydraulic components such as actuators, hoses, aqueducts, and irrigation systems that distribute water using gravity to create water pressure. These systems essentially use the properties of water to make the water deliver itself.
Force multiplication can be created by using a smaller diameter cylinder to push a larger piston into a larger cylinder. Often there will be many pistons.
All types of hydraulic pumps apply pressure to fluids (typically hydraulic oils) by moving a piston through the cylinder and controlling valves to control the fluid flow rate of the oil.
What are the applications of hydraulic systems?
There are numerous applications for hydraulic systems.
Hydraulics are widely used in the automotive industry in everything from braking systems to power steering. However, they are also used in construction equipment, manufacturing machines and aircraft.
Hydraulics are so common that you probably interact with hydraulic-based systems many times throughout the day without even realizing it.
Fluids in motion or under pressure performed useful work for humanity for centuries before French scientist-philosopher Blaise Pascal and Swiss physicist Daniel Bernoulli formulated the laws on which modern hydraulic power technology is based. Pascal's principle, formulated in about 1650, states that pressure in a liquid is transmitted equally in all directions; that is, when water fills a closed container, pressure applied at any point will be transmitted throughout the container. Pascal's principle is used to increase force in the hydraulic press; A small force applied to a small piston in a small cylinder is transmitted through a tube to a large cylinder, where pressure is exerted equally on all sides of the cylinder, including the large piston.
Bernoulli's theorem, formulated about a century later, states that the energy in a fluid arises from height, motion and pressure, and that the sum of the energies remains constant if there are no losses due to friction and no work done. Thus, the kinetic energy resulting from the motion can be partially converted into pressure energy by widening the cross-section of the pipe, which slows the flow but increases the area over which the liquid presses.
It was not until the 19th century that it was possible to develop speeds and pressures much higher than those provided by nature, but the invention of pumps brought great potential for the application of the discoveries of Pascal and Bernoulli. In 1882 the City of London built a hydraulic system that supplied pressurized water from the street mains to power machinery in factories. A significant advance in hydraulic techniques was made in 1906 when the oil hydraulic system was installed to lift and control the guns of the USS Virginia. In the 1920s, self-contained hydraulic units consisting of pump, controls and motor were developed.
It paves the way for applications in machine tools, automobiles, agricultural equipment, earthmovers, locomotives, ships, aircraft and spacecraft.
There are five elements in hydraulic power systems: drive, pump, control valves, motor and load. The drive can be an electric motor or any type of motor. The pump essentially tries to increase the pressure. The motor may be a counterpart to the pump that converts hydraulic input into mechanical output. Motors can produce rotation or reciprocating motion in the load.
Fluid power can compete successfully with mechanical and electrical systems in the operation and control of machine tools, agricultural machinery, construction machinery, and mining machinery (see fluids). Its main advantages are flexibility and the ability to multiply forces efficiently; It also ensures fast and accurate response to controls.
log dividers
A log splitter is a single-piston hydraulic machine that uses a valve at each end of the cylinder to move pistons with pressurized fluid, moving a wedge to split the wood into smaller pieces and return to the starting position.
diggers
Industrial equipment such as a backhoe often uses several rollers to move different parts. Electronic controls are often used for these more complex installations on large, powerful equipment.
The digger's hydraulic system operates the bucket, bucket arm and extendable boom.
bucket trucks
Bucket trucks, also known as cherry pickers, use hydraulics to lift and lower the operator in the bucket for work on elevated lines or other elevated areas. The hydraulic system can also be used to rotate the bucket.
As you can see, hydraulic systems have a wide range of applications in many different industries.
Hydraulic and pneumatic systems
Hydraulics are functionally similar to pneumatic systems. Both systems use pressurized fluid power, but hydraulics, unlike pneumatics, use liquids instead of gases.
Hydraulic systems can withstand more significant pressures: up to 10,000 pounds per square inch (psi), compared to about 100 psi in pneumatic systems.
This pressure is due to the incompressibility of fluids and allows for more significant power transfer with increased efficiency, as no energy is lost due to compression, except when air enters the hydraulic lines. Hydraulic fluids can also lubricate, cool and transmit hydraulic power.
Because pneumatics are less versatile, they require separate oil lubrication, which can cause confusion with air pressure.
Pneumatics are simpler in design and control and safer with less risk of fire, partly because the compressibility of the gas-absorbing shock can protect the mechanism.
Hydraulic power systems have become one of the major energy transmission technologies used in all stages of industrial, agricultural and defense activities. For example, modern aircraft use hydraulic systems to activate their controls and operate the landing gear and brakes. Almost all missiles and ground support equipment use smooth power. Hydraulic power systems are used in automobile transmissions, brakes and steering mechanisms. The foundations of mass production and its product automation in many industries are based on the use of fluid power systems. Fracking, more commonly known as hydraulic fracturing, has enabled the extraction of natural gas and oil from previously inaccessible deposits.