Internal Combustion Engines Assignment Help & Online Tutoring

An internal combustion engine burns fuel inside its cylinders, so the hot expanding gases push the pistons and turn the crankshaft. Petrol and diesel engines are the main types studied. They are compared with external combustion engines, such as steam plants, where burning happens outside the working cylinder.

The four strokes are intake, compression, power and exhaust. The piston draws in the mixture, compresses it, is driven down by combustion, then pushes out the burnt gases. The crankshaft turns twice for each power stroke, which is why it is called a four-stroke cycle.

In the ideal Otto cycle, heat is added at constant volume. In the ideal Diesel cycle, heat is added at constant pressure. Both are air-standard models used to analyse real engines, and they have different efficiency formulas, so check which one a question requires.

Compression ratio is the ratio of the cylinder volume when the piston is at the bottom of its stroke to the volume when it is at the top. Higher ratios generally raise efficiency, but in petrol engines they are limited by knock, which depends on fuel quality.

Diesel engines run at higher compression ratios and use lean mixtures, which raises thermal efficiency. They also avoid throttling losses at part load. In exchange, they are heavier, usually noisier, and their emissions of particulates and nitrogen oxides need careful control.

Indicated power is the power developed inside the cylinder, calculated from the pressure-volume diagram. Brake power is measured at the output shaft and is lower, because some power is lost to friction and to driving auxiliaries. Their difference is called friction power.

Mean effective pressure is the constant pressure that would produce the same work in one cycle as the actual varying pressure. It allows engines of different sizes to be compared. Indicated mean effective pressure comes from the indicator diagram, while brake mean effective pressure uses brake power.

Knock is the rapid, uncontrolled burning of unburnt mixture ahead of the flame front in a petrol engine. It causes a sharp noise and can damage the engine. Fuel octane rating, compression ratio, ignition timing and temperature all affect how likely knock is to occur.

Volumetric efficiency compares the actual mass of air drawn into the cylinder with the mass that would fill its swept volume at inlet conditions. Higher values mean better breathing and usually more power. Valve timing, port design and forced induction all affect it.

A two-stroke engine completes its cycle in one crankshaft revolution, so it has a power stroke every revolution. A four-stroke engine takes two revolutions. Two-strokes can give more power for their size, but they generally have higher emissions and worse fuel economy.

Brake specific fuel consumption is the fuel mass used per unit of brake power output per hour, often in g/kWh. A lower value means a more efficient engine. It is widely used to compare engines at different operating points, so it appears in many performance questions.

Ideal cycles assume air as the working fluid, no friction, instant heat addition and no heat loss. Real engines lose energy to friction, heat transfer through cylinder walls, incomplete combustion, pumping losses and exhaust gas energy. State these when a question asks you to compare.

The main regulated emissions are carbon monoxide, unburnt hydrocarbons, nitrogen oxides and particulates. Carbon dioxide is a product of complete combustion. Control methods include catalytic converters, exhaust gas recirculation and particulate filters. Limits vary by country and date, so check the standard in your question.

Include the aim, test setup, instruments, readings and calculations, then plots of power, torque and fuel consumption against speed. Discuss sources of error and compare your results with expected trends. Follow your department's report format and state the units and uncertainty for each measurement.

Yes. A one-to-one tutor can explain the cycles, work through efficiency and power calculations and check your reasoning and units. You complete your own assessed work in line with your university's rules. Lessons take place online and can follow your own course notes.