mechanical science and engineering pdf

Mechanical Science And Engineering Pdf

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Save extra with 2 Offers. About The Book Mechanical Sciences Book Summary: Primarily intended for the first-year undergraduate students of various engineering disciplines, this comprehensive and up-to-date text also serves the needs of second-year undergraduate students Mechanical, Civil, Aeronautical, Chemical, Production and Marine Engineering studying Engineering Thermodynamics and Fluid Mechanics. The whole text is divided into two parts and gives a detailed description of the theory along with the systematic applications of laws of Thermodynamics and Fluid Mechanics to engineering problems. Part I Chapters deals with the energy interaction between system and surroundings, while Part II Chapters covers the fluid flow phenomena. This accessible and comprehensive text is designed to take the student from an elementary level to a level of sophistication required for the analysis of practical problems.

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Log In Sign Up. Download Free PDF. Mechanical science. Anton Fitriyadi. Download PDF. A short summary of this paper. Although several types of prime movers are available gasoline engines, steam and gas turbines , the diesel engine is the most commonly used. Diesel engines provide a self-reliant energy source that is available in sizes from a few horsepower to 10, hp. Figure 1 provides an illustration of a common skid-mounted, diesel-driven generator. Relatively speaking, diesel engines are small, inexpensive, powerful, fuel efficient, and extremely reliable if maintained properly.

Because of the widespread use of diesel engines at DOE facilities, a basic understanding of the operation of a diesel engine will help ensure they are operated and maintained properly.

Due to the large variety of sizes, brands, and types of engines in service, this module is intended to provide the fundamentals and theory of operation of a diesel engine.

Specific information on a particular engine should be obtained from the vendor's manual. Rev The modern diesel engine came about as the result of the internal combustion principles first proposed by Sadi Carnot in the early 19th century.

Rudolf Diesel applied Sadi Carnot's principles into a patented cycle or method of combustion that has become known as the "diesel" cycle. His patented engine operated when the heat generated during the compression of the air fuel charge caused ignition of the mixture, which then expanded at a constant pressure during the full power stroke of the engine.

Diesel's first engine ran on coal dust and used a compression pressure of psi to increase its theoretical efficiency. Also, his first engine did not have provisions for any type of cooling system. Consequently, between the extreme pressure and the lack of cooling, the engine exploded and almost killed its inventor.

After recovering from his injuries, Diesel tried again using oil as the fuel, adding a cooling water jacket around the cylinder, and lowering the compression pressure to approximately psi. This combination eventually proved successful. Production rights to the engine were sold to Adolphus Bush, who built the first diesel engines for commercial use, installing them in his St.

Louis brewery to drive various pumps. Diesel EnginesA diesel engine is similar to the gasoline engine used in most cars. Both engines are internal combustion engines, meaning they burn the fuel-air mixture within the cylinders.

Both are reciprocating engines, being driven by pistons moving laterally in two directions. The majority of their parts are similar. Although a diesel engine and gasoline engine operate with similar components, a diesel engine, when compared to a gasoline engine of equal horsepower, is heavier due to stronger, heavier materials used to withstand the greater dynamic forces from the higher combustion pressures present in the diesel engine.

The greater combustion pressure is the result of the higher compression ratio used by diesel engines. The compression ratio is a measure of how much the engine compresses the gasses in the engine's cylinder.

In a gasoline engine the compression ratio which controls the compression temperature is limited by the air-fuel mixture entering the cylinders. The lower ignition temperature of gasoline will cause it to ignite burn at a compression ratio of less than The average car has a compression ratio.

In a diesel engine, compression ratios ranging from to as high as are commonly used. The higher compression ratios are possible because only air is compressed, and then the fuel is injected.

This is one of the factors that allows the diesel engine to be so efficient. Compression ratio will be discussed in greater detail later in this module. Another difference between a gasoline engine and a diesel engine is the manner in which engine speed is controlled. In any engine, speed or power is a direct function of the amount of fuel burned in the cylinders.

Gasoline engines are self-speed-limiting, due to the method the engine uses to control the amount of air entering the engine. Engine speed is indirectly controlled by the butterfly valve in the carburetor. The butterfly valve in a carburetor limits the amount of air entering the engine.

In a carburetor, the rate of air flow dictates the amount of gasoline that will be mixed with the air. Limiting the amount of air entering the engine limits the amount of fuel entering the engine, and, therefore, limits the speed of the engine. Diesel engines are not self-speed-limiting because the air oxygen entering the engine is always the maximum amount. Therefore, the engine speed is limited solely by the amount of fuel injected into the engine cylinders.

Therefore, the engine always has sufficient oxygen to burn and the engine will attempt to accelerate to meet the new fuel injection rate. Because of this, a manual fuel control is not possible because these engines, in an unloaded condition, can accelerate at a rate of more than revolutions per second. Diesel engines require a speed limiter, commonly called the governor, to control the amount of fuel being injected into the engine.

Unlike a gasoline engine, a diesel engine does not require an ignition system because in a diesel engine the fuel is injected into the cylinder as the piston comes to the top of its compression stroke. When fuel is injected, it vaporizes and ignites due to the heat created by the compression of the air in the cylinder.

Major Components of a Diesel EngineTo understand how a diesel engine operates, an understanding of the major components and how they work together is necessary. Figure 2 is an example of a medium-sized, four-stroke, supercharged, diesel engine with inlet ports and exhaust valves. Figure 3 provides a cross section of a similarly sized V-type diesel engine. In a liquid-cooled diesel, the block also provides the structure and rigid frame for the engine's cylinders, water coolant and oil passages, and support for the crankshaft and camshaft bearings.

The crankcase is defined as the area around the crankshaft and crankshaft bearings. This area encloses the rotating crankshaft and crankshaft counter weights and directs returning oil into the oil pan. The oil pan is located at the bottom of the crankcase as shown in Figure 2 and Figure 3. The oil pan collects and stores the engine's supply of lubricating oil. Large diesel engines may have the oil pan divided into several separate pans.

Cylinder Sleeve or BoreDiesel engines use one of two types of cylinders. In one type, each cylinder is simply machined or bored into the block casting, making the block and cylinders an integral part. In the second type, a machined steel sleeve is pressed into the block casting to form the cylinder. Figure 2 and Figure 3 provide examples of sleeved diesel engines. With either method, the cylinder sleeve or bore provides the engine with the cylindrical structure needed to confine the combustion gasses and to act as a guide for the engine's pistons.

Figure 5 provides an example of a wet sleeve. The volume enclosed by the sleeve or bore is called the combustion chamber and is the space where the fuel is burned. In either type of cylinder, sleeved or bored, the diameter of the cylinder is called the bore of the engine and is stated in inches. For example, the bore of a cubic inch Chevrolet gasoline engine is 4 inches. Most diesel engines are multi-cylinder engines and typically have their cylinders arranged in one of two ways, an in-line or a "V", although other combinations exits.

In an in-line engine, as the name indicates, all the cylinders are in a row. In a "V" type engine the cylinders are arranged in two rows of cylinders set at an angle to each other that align to a common crankshaft.

Each group of cylinders making up one side of the "V" is referred to as a bank of cylinders. The piston rides in the cylinder liner or sleeve as shown in Figure 2 and Figure 3.

Pistons are commonly made of aluminum or cast iron alloys. To prevent the combustion gasses from bypassing the piston and to keep friction to a minimum, each piston has several metal rings around it, as illustrated by Figure 6.

The rings are usually made of cast iron and coated with chrome or molybdenum. Most diesel engine pistons have several rings, usually 2 to 5, with each ring performing a distinct function. The top ring s acts primarily as the pressure seal. The intermediate ring s acts as a wiper ring to remove and control the amount of oil film on the cylinder walls. The bottom ring s is an oiler ring and ensures that a supply of lubricating oil is evenly deposited on the cylinder walls.

Connecting RodThe connecting rod connects the piston to the crankshaft. See Figure 2 and Figure 3 for the location of the connecting rods in an engine. The rods are made from drop-forged, heat-treated steel to provide the required strength. Each end of the rod is bored, with the smaller top bore connecting to the piston pin wrist pin in the piston as shown in Figure 6. The large bore end of the rod is split in half and bolted to allow the rod to be attached to the crankshaft.

Some diesel engine connecting rods are drilled down the center to allow oil to travel up from the crankshaft and into the piston pin and piston for lubrication.

A variation found in V-type engines that affects the connecting rods is to position the cylinders in the left and right banks directly opposite each other instead of staggered most common configuration. This arrangement requires that the connecting rods of two opposing cylinders share the same main journal bearing on the crankshaft. To allow this configuration, one of the connecting rods must be split or forked around the other. CrankshaftThe crankshaft transforms the linear motion of the pistons into a rotational motion that is transmited to the load.

Crankshafts are made of forged steel. The forged crankshaft is machined to produce the crankshaft bearing and connecting rod bearing surfaces. The rod bearings are eccentric, or offset, from the center of the crankshaft as illustrated in Figure 7. This offset converts the reciprocating up and down motion of the piston into the rotary motion of the crankshaft.

Mechanical engineering books

Not a MyNAP member yet? Register for a free account to start saving and receiving special member only perks. Mechanical engineering is critical to the design, manufacture, and operation of small and large mechanical systems throughout the U. It is often called upon to provide scientific and technological solutions for national problems, playing a key role in the transportation, power generation, advanced manufacturing, and aviation industries, to mention a few. These technologies include: micro- and nano-technologies, cellular and molecular biomechanics, information technology, and energy and environment issues.


Purchase Mechanical Engineering Science - 1st Edition. Print Book & E-Book. ISBN ,


Springer Handbook of Mechanical Engineering

Mechanical Engineering is a professional engineering discipline which involves the application of principles of physics, design, manufacturing and maintenance of mechanical systems. It requires a solid understanding of the key concepts including mechanics, kinematics, thermodynamics and energy. Mechanical engineers use these principles and others in the design and analysis of automobiles, aircrafts, heating and cooling systems, industrial equipment and machinery. In addition to these main areas, specialized fields are necessary to prepare future engineers for their positions in industry, such as mechatronics and robotics, transportation and logistics, fuel technology, automotive engineering, biomechanics, vibration, optics and others. Accordingly, the Springer Handbook of Mechanical Engineering devotes its contents to all areas of interest for the practicing engineer as well as for the student at various levels and educational institutions.

Mechanical engineering is a diverse and flexible engineering discipline. Mechanical engineers work in number of fields including design of machinery, controls, vibrations and acoustics, power generation, renewable energy, energy conservation, fluid flow and heat transfer applications, and air-conditioning. The program synthesizes math, science, engineering science, and engineering design. The program provides electives in several general areas, including thermal-sciences, mechanical design and manufacturing, robotics and automation, mechanical and environmental systems, nuclear engineering, aerospace engineering, and bioengineering. Students begin the practice of design in their freshman year and integrate it throughout their programs which culminate in a team-oriented capstone design project in the senior year.

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