Fluid Mechanics and Fluid Machinery Laboratory. Assignment Submitted to Mr.A.M.Sreenath

2012

Paul Alex B090541ME Rasheek M P B100598ME Ratan Sadanand O M B100453ME Raushan Kumar B100543ME Razal Faizal B100040ME Rituraj B100346ME

1.List of Hydroelectric Power Plants in India which uses

a)Pelton Turbine

S No Scheme Source of Water

Manufacturer No. Turbines

Power HP (each)

1 Mandi Hydroelectic Scheme

Uhl river Boving & Co. 4 17,250

2 Shimla Hydroelectric Scheme

Nauti River Boving & Co 3 380

3 Sharavati Hydroelectric Project

Sharavati River

Neyrpic 8 125,000

4 Pallivasal Project

Mudhirapuzha Escher Wyss 3 6000

5 Koyna Hydroelectric Project

Koyna River Neyrpic 4 +4 +2 87,500+ 100,000+ 27,000

b)Francis Turbine

S No Scheme Source of Water

Manufacturer No. Turbines

Power HP (each)

1 Bhakra Dam Project

Sutlej River Hitachi, USSR

5 +5 1,50,000 + 1,70,000

2 Damodar Valley Corp.

Barakar River

- 2 2,500

3 Periyar Hydroelectric Scheme

Periyar River

Voith 3 50,000

4 Chambal Hydroelectric Scheme

Chambal Voith 3 34,000

5 Hirakud Dam Project

Mahanadi River

Voith 2 32,000

C) Kaplan Turbines

S No Scheme Source of Water

Manufacturer No. Turbines

Power HP (each)

1 Tungabhadra Hydroelectric Scheme

Tunghabhadra Dam

Hitachi 2 13,800

2 Nangal Bhakra Project

Nangal Hydel Channel

Hitachi 2 34,000

3 Ganga Hydroelectric Scheme

Ganga Canal Voith , English Electric

3 +3 4000 +4300

4 Nizamsagar Project

Nanjira River - 3 7050

5 Hirakud Project

Mahanadi River

Voith 4 52,000

List Practical applications where the following devices are used:

a) Notches

1.To measure flow rates in open channel flow.

2. Flow measurement in gates and canals.

b) Gear Pump : They are used in the following applications :

1. Internal gear pumps are greatly used in food industry for pumping things like

chocolate, fillers and cacao butter.

2. Metering molten plastics in forming synthetic fibers, filaments, films and pipes.

3. Used for hydraulic transmission system.

4. Chemical metering.

5. Metering fuels and chemical additives

c) Reciprocating Pumps : Their main uses are as follows:

1. Reciprocating pumps are used in High performance liquid chromatography(HPLC).

2. Wind pumps used to pump water in farms/ semi arid area are basically

reciprocating pumps driven by wind power

3. Hand pumps are manually operated reciprocating pumps; they use human power

and mechanical advantage to move fluids or air from one place to another.

They are widely used in every country in the world for a variety of industrial,

marine, irrigation and leisure activities.

4. Radial Piston pumps are reciprocating pumps with hydrostatically balanced parts

and are used in machine tools (e. g. displace of cutting emulsion, supply for

hydraulic equipment like cylinders) , automotive sector (e. g. automatic

transmission, hydraulic suspension control in upper-class cars) and high

pressure units (HPU) (e. g. for overload protection of presses)

5. Axial Piston pumps type of pump can contain most of the necessary circuit

controls integrally (the swash-plate angle control) to regulate flow and pressure,

be very reliable and allow the rest of the hydraulic system to be very simple and

inexpensive)

d) Venturimeter/Nozzlemeter/Orificemeter.

1.Used in industries to measure the flow rate of gases and liquids.

2.Used in measurement of volume flow of blood through vessels. One method is by

inserting an accurately calibrated Venturi meter made of glass into the circulation.

3. Venturi meters are used in pipelines at wastewater collection systems and

treatment plants. They are used in wastewater pipes because their overall design

structure allows for solids to pass through it instead of collecting in front of it.

4. The venturi in carburetors is used to measure airflow in a car engine and to

ensure that a correct amount of fuel is fed to the gas combustion engine when

needed during driving.

5. The temperatures and pressures of chemicals in a pipeline do not affect the

accuracy of a Venturi flowmeter and because of this they are used in crude oil

pipelines.

3A - Measurement of Petrol in Petrol Pumps

As the gasoline travels upward into the dispenser, it passes through a flow control valve that regulates the gasoline's flow speed. It does this via a plastic diaphragm that gets squeezed more and more tightly into the pipe as the flow of gas increases, always leaving just enough room for the proper amount of gasoline to get through. If you've set a predetermined amount of gas to be pumped, the flow of gas will slow down as you approach the limit.

This pipe also contains the flow meter, which is a cast iron or aluminium chamber containing a series of gears or a simple rotor that ticks off units of gas as they pass through. Information about the gas flow is passed on to a computer located in the dispenser, which displays the metered amount of gas in tenths of a gallon. As the temperature of the gas changes -- on particularly hot and cold days, for instance -- the density of the gas may change, causing an error in the amount of fluid measured by the flow meter. The computer compensates this error by taking the gas temperature into account as it records the flow and adjusts the price accordingly.

Wear and tear on the meter may degrade its accuracy over time, which is why periodic inspections are necessary. Typically, inspectors will use a container of a certain volume, pump gas into it and compare the amount in the container with the amount metered on the dispenser. If the amounts don't match, the flow meter will need to be recalibrated and possibly refurbished or replaced.

3B –Torque Convertor

Torque converter elements

A fluid coupling is a two element drive that is incapable of multiplying torque, while a torque converter has at least one extra element—

the stator—which alters the drive's characteristics during periods of high slippage, producing an increase in output torque.

In a torque converter there are at least three rotating elements: the impeller, which is mechanically driven by the prime mover; the

turbine, which drives the load; and the stator, which is interposed between the impeller and turbine so that it can alter oil flow returning

from the turbine to the impeller. The classic torque converter design dictates that the stator be prevented from rotating under any

condition, hence the term stator. In practice, however, the stator is mounted on an overrunning clutch, which prevents the stator from

counter-rotating with respect to the prime mover but allows forward rotation.

Modifications to the basic three element design have been periodically incorporated, especially in applications where higher than normal

torque multiplication is required. Most commonly, these have taken the form of multiple turbines and stators, each set being designed to

produce differing amounts of torque multiplication. For example, the Buick Dynaflow automatic transmission was a non-shifting design

and, under normal conditions, relied solely upon the converter to multiply torque. The Dynaflow used a five element converter to

produce the wide range of torque multiplication needed to propel a heavy vehicle.

Although not strictly a part of classic torque converter design, many automotive converters include a lock-up clutch to improve cruising

power transmission efficiency and reduce heat. The application of the clutch locks the turbine to the impeller, causing all power

transmission to be mechanical, thus eliminating losses associated with fluid drive.

Operational phases

A torque converter has three stages of operation:

Stall. The prime mover is applying power to the impeller but the turbine cannot rotate. For example, in an automobile, this stage of

operation would occur when the driver has placed the transmission in gear but is preventing the vehicle from moving by continuing

to apply the brakes. At stall, the torque converter can produce maximum torque multiplication if sufficient input power is applied

(the resulting multiplication is called the stall ratio). The stall phase actually lasts for a brief period when the load (e.g., vehicle)

initially starts to move, as there will be a very large difference between pump and turbine speed.

Acceleration. The load is accelerating but there still is a relatively large difference between impeller and turbine speed. Under this

condition, the converter will produce torque multiplication that is less than what could be achieved under stall conditions. The

amount of multiplication will depend upon the actual difference between pump and turbine speed, as well as various other design

factors.

Coupling. The turbine has reached approximately 90 percent of the speed of the impeller. Torque multiplication has essentially

ceased and the torque converter is behaving in a manner similar to a simple fluid coupling. In modern automotive applications, it is

usually at this stage of operation where the lock-up clutch is applied, a procedure that tends to improve fuel efficiency.

The key to the torque converter's ability to multiply torque lies in the stator. In the classic fluid coupling design, periods of high slippage

cause the fluid flow returning from the turbine to the impellor to oppose the direction of impeller rotation, leading to a significant loss of

efficiency and the generation of considerable waste heat. Under the same condition in a torque converter, the returning fluid will be

redirected by the stator so that it aids the rotation of the impeller, instead of impeding it. The result is that much of the energy in the

returning fluid is recovered and added to the energy being applied to the impeller by the prime mover. This action causes a substantial

increase in the mass of fluid being directed to the turbine, producing an increase in output torque. Since the returning fluid is initially

travelling in a direction opposite to impeller rotation, the stator will likewise attempt to counter-rotate as it forces the fluid to change

direction, an effect that is prevented by the one-way stator clutch.

Unlike the radially straight blades used in a plain fluid coupling, a torque converter's turbine and stator use angled and curved blades.

The blade shape of the stator is what alters the path of the fluid, forcing it to coincide with the impeller rotation. The matching curve of

the turbine blades helps to correctly direct the returning fluid to the stator so the latter can do its job. The shape of the blades is

important as minor variations can result in significant changes to the converter's performance.

During the stall and acceleration phases, in which torque multiplication occurs, the stator remains stationary due to the action of its one-

way clutch. However, as the torque converter approaches the coupling phase, the energy and volume of the fluid returning from the

turbine will gradually decrease, causing pressure on the stator to likewise decrease. Once in the coupling phase, the returning fluid will

reverse direction and now rotate in the direction of the impellor and turbine, an effect which will attempt to forward-rotate the stator. At

this point, the stator clutch will release and the impeller, turbine and stator will all (more or less) turn as a unit.

Unavoidably, some of the fluid's kinetic energy will be lost due to friction and turbulence, causing the converter to generate waste heat

(dissipated in many applications by water cooling). This effect, often referred to as pumping loss, will be most pronounced at or near

stall conditions. In modern designs, the blade geometry minimizes oil velocity at low impeller speeds, which allows the turbine to be

stalled for long periods with little danger of overheating.

3C – Mechanical Water Meter

Types of meters

There are two major methods of flow measurement in use, displacement and velocity, with sub-technologies within each of them. Common displacement designs include oscillating piston and nutating disk meters. Velocity-based designs include single- and multi-jet meters and turbine meters. There are also non-mechanical designs, for example electromagnetic and ultrasonic meters.

In addition to the more common types of meter, there are meters designed for special uses. Most meters in a typical water distribution system are designed for cold potable water only. There are specialty water meters manufactured for specific other uses. Hot water meters are designed with special materials that can withstand higher temperatures. Meters for reclaimed water have special lavender register covers to signify that the water is non-potable and should not be used for drinking. Water meters are generally owned, read, and maintained by a public water provider such as a city, rural water association, or private water company. In some cases an owner of a mobile home park, apartment complex or commercial building may be billed by a utility on one meter, and want to share the cost of the bill among the tenants. In this case, private meters may be purchased to separately track usage of each unit in what is called sub metering.

Displacement water meters

This type of water meter is most often used in residential and small commercial applications. Displacement meters are commonly referred to as Positive Displacement, or "PD" meters. Two common methods of positive displacement measuring are Oscillating Piston meters and Nutating Disk meters. Either method relies on the water to physically displace the moving measuring element in direct relation to the amount of water that passes through the meter. The piston or disk moves a magnet that drives the register.

PD meters are generally very accurate at low to moderate flow rates typical of residential and small commercial users, and are common in sizes from 5/8" to 2". Because displacement meters rely on all water flowing through the meter to "push" the measuring element, they generally are not practical in large commercial applications requiring high flow rates or low pressure loss. PD meters normally have a built-in strainer to protect the measuring element from rocks or other debris that could stop or break the measuring element. PD meters normally have bronze, brass or plastic bodies with internal measuring chambers made from molded plastics and stainless steel.

Velocity water meters

A velocity-type meter measures the velocity of flow through a meter of a known internal capacity. The speed of the flow can then be converted into volume of flow for usage. There are several types of meters that measure water flow velocity to determine totality usage. They include jet meters (single-jet and multi-jet), turbine meters, propeller meters, and mag meters. Most velocity-based meters have an adjustment vane for calibration of the meter to required accuracy.

3 D: Electromagnetic Flow Meter

Magnetic flow meters, commonly referred to as "mag meters", are technically a velocity-type water meter,

except that they use electromagnetic properties to determine the water flow velocity, rather than mechanical

means which jet and turbine meters use. Mag meters use the physics principle of Faraday's law of

induction for measurement, and require AC or DC electricity from line or battery to operate

the electromagnets. Since mag meters have no mechanical measuring element, they normally have the

advantage of being able to measure flow in either direction, or use electronics for measuring and totalizing the

flow. Mag meters can also be useful for measuring untreated water, raw (untreated/unfiltered) water, and

wastewater, since there is no mechanical measuring element to get clogged or damaged by debris flowing

through the meter. Strainers are not required with mag meters, since there is no measuring element in the

stream of flow that could be damaged. Stray electrical energy flowing through the flow tube can cause

inaccurate readings, therefore most mag meters are installed with either grounding rings or

grounding electrodes to divert stray electricity away from the electrodes inside the flow tube which are used

to measure the flow.

3 E : MECHANICAL PRESSURE GAUGES

Hydrostatic

Hydrostatic gauges (such as the mercury column manometer) compare pressure to the hydrostatic force per

unit area at the base of a column of fluid. Hydrostatic gauge measurements are independent of the type of gas

being measured, and can be designed to have a very linear calibration. They have poor dynamic response.

Piston

Piston-type gauges counterbalance the pressure of a fluid with a spring (for example tire-pressure gauges of

comparatively low accuracy) or a solid weight, in which case it is known as a deadweight tester and may be

used for calibration of other gauges.

Liquid Column

Liquid column gauges consist of a vertical column of liquid in a tube that has ends which are exposed to

different pressures. The column will rise or fall until its weight is in equilibrium with the pressure differential

between the two ends of the tube. A very simple version is a U-shaped tube half-full of liquid, one side of

which is connected to the region of interest while the reference pressure (which might be the atmospheric

pressure or a vacuum) is applied to the other. The difference in liquid level represents the applied pressure.

The pressure exerted by a column of fluid of height h and density ρ is given by the hydrostatic pressure

equation, P = hgρ. Therefore the pressure difference between the applied pressure Pa and the reference

pressure P0 in a U-tube manometer can be found by solving Pa − P0 = hgρ. In other words, the pressure on

either end of the liquid (shown in blue in the figure to the right) must be balanced (since the liquid is static)

and so Pa = P0 + hgρ. If the fluid being measured is significantly dense, hydrostatic corrections may have to be

made for the height between the moving surface of the manometer working fluid and the location where the

pressure measurement is desired except when measuring differential pressure of a fluid (for example across

an orifice plate or venturi), in which case the density ρ should be corrected by subtracting the density of the

fluid being measured.

McLeod Gauge A McLeod gauge isolates a sample of gas and compresses it in a modified mercury manometer until the pressure is a few mmHg. The gas must be well-behaved during its compression (it must not condense, for example). The technique is slow and unsuited to continual monitoring, but is capable of good accuracy

Bourdon Gauge

In practice, a flattened thin-wall, closed-end tube is connected at the hollow end to a fixed pipe containing the

fluid pressure to be measured. As the pressure increases, the closed end moves in an arc, and this motion is

converted into the rotation of a (segment of a) gear by a connecting link that is usually adjustable. A small-

diameter pinion gear is on the pointer shaft, so the motion is magnified further by the gear ratio. The

positioning of the indicator card behind the pointer, the initial pointer shaft position, the linkage length and

initial position, all provide means to calibrate the pointer to indicate the desired range of pressure for

variations in the behaviour of the Bourdon tube itself. Differential pressure can be measured by gauges

containing two different Bourdon tubes, with connecting linkages.