Engine Parameters Analysis - Lab Report Example

Finally, the volumetric efficiency was found to be 60%. It is important to point out that the torque of the engine is dependent on the speed at which the engine turns and it is normally expressed in revolutions per minute (rpm).

The curve of the power torque graph for the polo engine slopes smoothly and increases steadily as the revolutions per minute increase. The relationship of torque versus the engine is nonlinear. This relationship is provided as a curve as shown on the torque curve. The exact shape and the height of the curve are specific for each engine type and this is normally determined by engine tests. The curve peaks at approximately 4000 rpm with a torque of about 90.3 N/M. The curves can be defined within the range of 1100-5500 rpm since that is the operating range of the polo engine. If the range is made lower than this, the engine is likely to stall while an increase would damage the engine.

The balance of the energy in the internal combustion engine will indicate that approximately 1/3 of the fuel energy that has been input is normally lost to the external environment through a transfer of heat. There is also another 1/3 is available as the shaft performs its work. The heat losses must be decreased to improve the efficiency of the engine.

Other IC engine parameters that can be used in the test of the polo engine are:

- Power and mechanical efficiency: In this case, the power that is developed by the engine is measured at the output shaft.

- The mean effective pressure and torque: In this case, the average pressure is normally assumed to be acting on the piston throughout the power stroke.

- Exhaust smoke and other emissions: The oxides of nitrogen and any unburned carbons are an indication of the rate of efficiency of the engine. This parameter can be used to determine the performance of the engine.

- Fuel air ratio: This can be determined as the ratio of the mass of fuel to the mass of air in the fuel-air mixture.

The dynamometer is a very appropriate way of measuring and evaluating the performance of the internal combustion engine. It has proved to be capable of measuring combustions with an efficiency of up to 60%.

The efficiency of the engine is reduced at small scales but increases as the range of the torque in the engine increases. The range of the power as determined on the power scale is dependent on the size of the combustion engine and this increases as the engine becomes bigger up to a certain set limit. This factor is taken into consideration by manufacturers to produce engines of great efficiency.