Assignment 2

Aim: To run the tutorial '1cylSI-final.gtm' and discuss the results.

Objective:

1) Case 1: To run the tutorial at 1800 rpm and list down important parameters such as Air flow rate, BMEP, BSFC, In-cylinder pressure.

2) Case 2: To run the tutorial at 3600 rpm and then increase the power by 10%.

Project map

Results: (Case 1 at 1800 rpm)

In-cylinder pressure

From the above table,

Brake power = 7 KW

Air flow rate = 24.6 Kg/h

BSFC = 244.2 g/KW-h

BMEP = 9.3 bar

In-cylinder pressure = 48.88 bar

Results: (Case 2 at 3600 rpm)

In order to increase the power of the SI engine, the stroke length is increased from 86 to 98 and rich mixture was introduced into the engine cylinder with fuel ratio of 12. The increase in stroke length increases the cylinder cross sectional area which helps in higher heat transfer rate which further leads to increase in power.

From the above tables,

Power obtained in case 1 = 16.4 KW

Power obtained in case 4 = 18.6 KW

Calculation percentage of increase in power from case 1 to case 4,

(18.6-16.4/16.4)*100 = 13.41%

Thus it can be concluded that the richer mixture and increasing stroke length increases engine power however, this leads to formation of pollutants such as carbon monoxide, unburned hydrocarbons and NOx, the formation of pollutants can be controlled by using catalyst.