THERMAL ENGINEERING LAB. Load Test on 4-Stroke Single cylinder Diesel Engine Test Rig. 3. THEORY: Single cylinder stationary, constant speed diesel. INSTITUTE OF AERONAUTICAL ENGINEERING. MECHANICAL ENGINEERING DEPARTMENT. THERMAL ENGINEERING LAB. LAB MANUAL. Subject Code. THERMAL ENGINEERING LAB MANUAL - Free download as Word Doc .doc /. docx), PDF File .pdf), Text File .txt) or read online for free.
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Aurora's Technological and Research Institute. Thermal Lab. Department of Mechanical. 1. THERMAL ENGINEERING. LAB MANUAL. B. Tech III Year - I. B.P Vs Indicated thermal efficiency. 5. Air fuel Ratio Vs B.P. 6. Air fuel Ratio Vs S.F.C. THEORY: The Test Ring consists of Four-Stroke Diesel Engine, to be tested. THERMAL ENGINEERING LAB MANUAL. goudzwaard.info: MRCET. DEPT. OF MECHANICAL ENGINEERING. Page 7 of Experiment No. 1. I.C. ENGINE.
No: Date: To draw the port timing diagram of given two stroke cycle petrol engine. Apparatus Required: Measuring tape Chalk Theory and Description: In the case of two stroke cycle engines the inlet and exhaust valves are not present.
Instead, the slots are cut on the cylinder itself at different elevation and they are called ports. There are three ports are present in the two stroke cycle engine. Inlet port 2. Transfer port 3. Exhaust port The diagram which shows the position of crank at which the above ports are open and close are called as port timing diagram The extreme position of the piston at the bottom of the cylinder is called Bottom Dead centre [BDC].
The transfer port is opened when the piston is moved from TDC to BDC and the fuel enters into the cylinder through this transport from the crank case of the engine. The transfer port opening and closing are measured with respect to the BDC.
The exhaust port opening and closing are measured with respect to the BDC. Procedure: Remove the ports cover and identify the three ports. To mark this position follow the same procedure as followed in valve timing diagram.
Rotate the flywheel slowly in usual direction usually clockwise and observe the movement of the piston When the piston moves from BDC to TDC observe when the bottom edge of the piston. Just uncover the bottom end of the inlet port. This is the inlet port closing IPC condition. Make the mark on the flywheel and measure the distance from TDC. This is the exhaust port closing condition [EPC]. Make the mark on the flywheel and measure the distance from BDC.
This is the transfer port opening [TPO] condition. This is the transfer port closing [TPC] condition. Note: 1. The inlet port opening distance and closing distance from TDC are equal. The exhaust port opening distance and closing distance from BDC are equal.
The radiant energy per unit time per unit area from the surface of the body is called, as the emissivity of the surface is the ratio of the emissive power of the surface to the emissive power of a black surface at the same temperature. It is noted by E. Emissivity being a property of the surface depends on the nature of the surface and temperature.
To be assumed equal to unity. Test plate made of circular aluminium plate with polished surface, mounted on asbestos cement sheet,diametermm 2. Black body made of circular aluminium plate with surface black Teflon coated, mounted on asbestos cement sheet,diametermm 3. Digital voltmeter and ammeter.
Enclosure size mm x mm x mm approximately with one side Perspex and bottom fitted on cement sheet. Thermocouples — Choromel Alumel — 3Nos. Channel selector and digital temper display. Regulator to vary input power to heaters independently. Gradually increase the input to the heater to black plate and adjust it to some value viz. Check the temperature of the two plates with small time intervals and adjust the input of test plate only, by the dimmerstat so that the two plates will be maintained at the same temperature.
This will required some trial and error and one has to wait sufficiently more than one hour or so to obtain the steady state condition. Lamont Boiler: A forced circulating boiler was first introduced in by Camont. The arrangement is shown in the figure. The most of sensible heat is supplied to the feed water passing through the Economizer.
A centrifugal pump circulates the water equal to 8 to 10 times the weight of steam evaporated tubes and the part of water supplied drum. The large quantity of water circulated prevents the tubes from being overheated. To secure the uniform flow of feed water through each of parallel boilers circuits a choke is fitted all the enhance to each circuits.
The feed water from the hot well is pumped with the help of a feed pump to boiler from the through economy. In boiler drawn the fed water is circulated to number of valves in the furnaces with fuel is burnt.
The feed water is evaporated into wet steam and the wet steam flows back to boiler drawn. In this its supplied to prime mover through steam outlet. Then the blue gases passes through the electrostatic precipitator. Study of steam turbines: A steam turbine is rotary machine which is designed to covert the energy of high temperature steam into mechanical power. In this the steam is first expanded in a set of nozzles or passages up to exit pressure where in the pressure energy of steam is converted into kinetic energy.
Reaction turbine 2. Direction of steam flow a. Axial b. Radial c. Tangential 3.
Number of pressure stages a. Single stage b. Multi stage 4. Method of governing a. Throttle b. Nozzle c. By-pass d. Combination of throttle , nozzle by pass. Impulse Turbine: Velocity compound impulse turbine Curtic Turbine Arrangement of velocity compounded impulse turbine is shown in fig. In this type of turbine steam expands in a set of nozzle from the boiler pressure up to the condenser pressure which converts its pressure energy into kinetic energy.
This high velocity steam is passed over the rings of moving blades, each ring of moving blades being separated by a ring of fixed blades. A part of high velocity steam is absorbed in the first ring of moving blades and remaining in the first ring of moving blades is passed to next ring of fixed blades. The function of fixed blades is to change the direction of flow of steam so that it can guide over the second ring of moving blades. The velocity of steam while passing over the fix blades is particularly constant except last for overcoming the friction losses.
Pressure compounded Impulse Turbine Rateau Turbine Arrangement of velocity compounds impulse turbine is steam is shown in fig. In this type of turbine the total pressure drop does not take place in a single ring of nozzle, but it is divided up in between the set of nozzle ring steam from the boiler is partially expanded in the first ring of nozzle and then it is passed over the ring of moving blades till its velocity is absorbed. Exhaust from blades till its velocity is absorbed.
Pressure Velocity compounded Impulse Turbine: Arrangement of velocity compounded impulse turbine is shown in figure. The total pressure drop of steam is due to expansion in each stage is also compounded. Reaction Turbine: Unlike impulse turbine nozzle are not provided in this turbine and also there is a continuous pressure drop in the rings of fixed and moving blades.
The function of fixed blades, which also get nozzle, is to change the direction of steam. So that it can enter into the ring of moving blades without shock the term reaction is used because the steam expands over the ring of moving blades giving a reaction on moving blades.
Observation and tabulation 1. To determine the kinematic viscosity and absolute viscosity of the given lubricating oil at different temperatures using Redwood Viscometer.
Apparatus required: The redwood viscometer consists of vertical cylindrical oil cup with an orifice in the centre of its base. The orifice can be closed by a ball. A hook pointing upward serves as a guide mark for filling the oil. The cylindrical cup is surrounded by the water bath.
The water bath maintains the temperature of the oil to be tested at constant temperature. The oil is heated by heating the water bath by means of an immersed electric heater in the water bath, The provision is made for stirring the water, to maintain the uniform temperature in the water bath and to place the thermometer ti record the temperature of oil and water bath. The cylinder is The orifice is 1. From the kinematic viscosity the dynamic viscosity is determined.
Theory and Definition: Viscosity is the property of fluid. It is defined as The internal resistance offered by the fluid to the movement of one layer of fluid over an adjacent layer. It is due to the Cohesion between the molecules of the fluid. The fluids which obey the Newton law of Viscosity are called as Newtonian fluid. The dynamic viscosity of fluid is defined as the shear required producing unit rate of angular deformation.
The kinematic viscosity of the fluid is defined as the ratio of the dynamic viscosity toss density of the fluid. Its symbol is r. Clean the cylindrical oil cup and ensure the orifice tube is free from dirt. Close the orifice with ball valve. Place the 50 ml flask below the opening of the Orifice. Fill the oil in the cylindrical oil cup up to the mark in the cup. Fill the water in the water bath. Insert the thermometers in their respective places to measure the oil and water bath temperatures.
Heat the by heating the water bath, Stirred the water bath and maintain the uniform temperature. At particular temperature lift the bal valve and collect the oil in the 50 ml flask and note the time taken in seconds for the collecting 50 ml of oil.
A stop watch is used measure the time taken. This time is called Redwood seconds.
Increase the temperature and repeat the procedure 8 and note down the Redwood seconds for different temperatures. The kinematic and dynamic viscosity of given oil at different temperatures were determined. To determine the flash and fire point temperatures of the given sample of lubricating oil using Cleveland open cup apparatus. Cleveland open cup apparatus 2. Thermometer 3. Splinter sticks 4. Sample of oil. The flash point of the lubricating oil is defined as the lowest temperature at which it forms vapours and produces combustible mixture with air.
The higher flash point temperature is always desirable for any lubricating oil. If the oil has the lower value of flash point temperatures, it will burn easily and forms the carbon deposits on the moving parts. The minimum flash temperature of the oil used in IC engines varies from C to C. When the oil is tested using the open cup apparatus, the temperature is slightly more than the above temperatures. The flash and fire point temperatures may differs by 20C to 60C when it is tested by open cup apparatus.
However, a greater difference may be obtained if some additives are mixed with oil. The flash and fire power point temperatures depends upon the volatility of the oil. The Cleveland open cup apparatus consists of a cylindrical cup of standard size. It is held in position in the metallic holder which is placed on a wire gauge.
It is heated by means of an electric heater housed inside the metallic holder. A provision is made on the top of the cup to hold the thermometer. A standing filling mark is done on the inner side of the cup and the sample of oil is filled up to the mark. This apparatus will give more accurate results than the pensky martins closed cup apparatus.
Clean the cup and fill it with the given sample of oil up to the filling mark.
Insert the thermometer in the holder. Make sure that the thermometer should not touch the metallic cup. Heat the oil by the means of electric heater so that the sample of oil gives out vapour at the rate of 10C per minute. When the oil gives out vapour, introduce the test flame above the oil, without touching the surface of the oil and watch for flash with flickering sound. Introducing the test flame should not continue at regular intervals until the flash is observed with peak flickering sound.
The temperature corresponding to this flickering sound is noticed and it is the flash point temperature of the given sample of oil. Continue the process of heating and introducing the test flame until the oil will begins to burn continuously and observe the temperature.
This is the fire pint temperature of the given sample of oil. Repeat the test twice or thrice with fresh sample of oil and observe the results. The observations are tabulated. The flash and fire point temperatures of the given sample of oil were determined using Cleveland open cup apparatus.
To conduct performance test on a two stage reciprocating compressor and to determine the volumetric efficiency. The test unit consisting of an air reservoir on air intake tank with an orifice and a U tube manometer, the compressor having pressure gauge, energy meter and stop watch.
D - Diameter of piston 0. Close the outlet valve. Fill up the manometer with water up to half level. Start the compressor and observe the pressure developing slowly.
At a particular test, pressure outlet valve is opened slowly and adjuster so that pressure in tank and maintained constant. Observe the following reading time taken for 5 revolution of energy meter disc. Manometer level Speed of the compressor in rpm. Thus performance test on a two stage reciprocating air compressor is conducted and graph is drawn for pressure and.
The test was conducted and the volumetric efficiency of the compressor was determined. Room temperature Barometric pressure Energy meter constant Diameter of Suction pipe: Note down the barometric pressure in mm of Hg and room temperature in C.
Start the blower. Adjust the delivery pressure by adjusting throttle at outlet side. To measure volume of air flow rate, measure velocity of suction air by using anemometer. Measure speed of blower by tachometer. Note the time in sec required for 5 revolutions of energy meter to measure power at inlet. Repeat same procedure 3 to 6 times for different pressure. Flag for inappropriate content. Related titles. Jump to Page. Search inside document.
A College of Engineering and Technology, Pollachi. Internal Examiner Date: External Examiner Date: