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The fuel is injected directly into the combustion chamber, which can be either a segmented combustion chamber or an unsegmented combustion chamber. Grundlagen Fahrzeug- und Motorentechnik. Large ships use extremely efficient, low-speed two-stroke Diesel engines.

For creating the fuel pressure, Diesel engines usually have an injection pump. Diesel's original engine injected fuel with the assistance of compressed air, which atomised the fuel and forced it into the engine through a nozzle a similar principle to an aerosol spray.

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Diesel fuel, compared to petrol is a less difficult to ignite b just about the same difficult to ignite c more difficult to ignite d highly ignitable e none of the above. Also, indirect injection engines generally run more satisfactorily on fuels with a high ignition delay for instance, petrol than direct injection engines.

Diesel engine

Diesel engine

Diesel engines have long been popular in bigger cars and have been used in smaller cars such as superminis in Europe since the s. Fuel oil consumption guarantees for I. Violent sound pulsations within the cylinder of an I. Wikimedia Commons has media related to Diesel engines.

This makes the Diesel engine very economical. The operation of forcing additional air under pressure in the engine cylinder is known as a scavenging b turbulence c supercharging d pre-ignition e dissociation and carburretion of fuel. Direct injection Diesel engines inject fuel directly into the cylinder. Non-road Diesel engines are commonly used for construction equipment.

These engines use injectors that are very precise spring-loaded valves that open and close at a specific fuel pressure. Instead of a full set of valves, two-stroke Diesel engines have simple intake ports, and exhaust ports or exhaust valves. The minimum value occurs in the range of a lean mixture b chemically correct mixture c rich mixture d unpredictable e none of the above. Aspirants will be selected based on the following criteria-. The precess of breaking up or a lipuid into fine droplets by spraying is called a vaporisation b carburetion c ionisation d injection e atomisation.

Critics have claimed that Diesel never invented a new motor and that the invention of the Diesel engine is fraud. Over the years many different injection methods have been used.

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The cam shaft of a four stroke I. So here we have updated the complete subject wise topic details so that it gets easier for the candidates to prepare well for the examination.

Piston rings are usually made of a cast iron b aluminium c phosphor bronze d babbitt e carbon steel. Crossflow scavenging is incomplete and limits the stroke, yet some manufacturers used it. Scavenging is usually done to increase a thermal efficiency b speed c power output d fuel consumption e all of the above. Also, most engines have a spill return system, by which any excess fuel from the injector pump and injectors is returned to the fuel tank.

Diesel engine

The following type of carburettor is preferred a concentric type b eccentric type c horizontal type d vertical type e none of the above. This is achieved by using a very rich air-fuel mixture, resulting in incomplete combustion. Filling the cylinder with air and compressing it takes place in one stroke, and the power and exhaust strokes are combined.

Diesel engines work by compressing only the air. Modern Diesel engines for lorries have to be both extremely reliable and very fuel efficient. Timeline of heat engine technology. Mechanically governed fuel injection systems are driven by the engine's gear train.

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The air standard efficiency of an Otto cycle compared to diesel cycle for the given compression ratio is a same b less c more d more or less depending on power rating e unpredictable. Several German manufacturers produced engines according to this standard. Common-Rail direct injection, turbocharging and four valves per cylinder are standard. Turbocharging can improve the fuel economy of Diesel engines by recovering waste heat from the exhaust, increasing the excess air factor, classroom management problems and solutions pdf and increasing the ratio of engine output to friction losses.

After several years of working on his ideas, Diesel published them in in the essay Theory and Construction of a Rational Heat Motor. The preferred location of an oil cooler is a before the filters b after the filters c between the filters d before and after the filters e any where. At about the top of the compression stroke, fuel is injected directly into the compressed air in the combustion chamber. Wikimedia Commons has media related to Rudolf Diesel.

Leakage past the piston rings and valve seats in I. Polymerisation is a chemical process in which molecules of a compound become a larger b slowed down c smaller d liquid e gaseous. For low load operation, more suitable economical engine is a S. Automobile emissions control Catalytic converter Diesel particulate filter Exhaust manifold Glasspack Muffler.

Combustion occurs at a substantially constant pressure during the initial part of the power stroke. To reduce the possibility of knock in the C.

The Diesel engine fuel auto-ignites due to compression ignition, and then ignites the gaseous fuel. The fuel then ignites due to compression heat. The Definitive Encyclopedia and Document Collection.

Separate high-pressure fuel lines connect the fuel pump with each cylinder. Leave a Reply Cancel reply Your email address will not be published. Therefore, mechanically controlled fuel injection and air-cooling are still very common.

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Normal heptane a accelerates auto-ignition b helps to resist auto-ignition c does not affect auto-ignition d has no relation with auto-ighition e retards auto-ignition. The timing is measured in degrees of crank angle of the piston before top dead centre. Diesel cycle and Reciprocating internal combustion engine. The requirements for marine Diesel engines vary, depending on the application.

Cetane a has zero cetane number b has cetane number c helps detonation d is a straight chain paraffin e determines the efficiency of an I. In order to prevent knock in the S.

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Fuel consumption with increase in back pressure will a increase b decrease c remain unaffected d depend on other factors e none of the above. The first Diesel engines for ships were made by A. Increasing the compression ratio in a spark-ignition engine where fuel and air are mixed before entry to the cylinder is limited by the need to prevent damaging pre-ignition.