GT-POWER- INCREASING THE POWER OUTPUT OF SINGLE CYINDER -SPARK-IGNITION -IC ENGINE BY 10 PERCENTAGE

1.Run the case at 1800 rpm and list down important parameters (20 Marks)

• air flow rate
• BMEP
• BSFC
• In-cylinder pressure

INTRODUCTION:

MEP: Mean Effective pressure is the pressure acting at the top of the piston during the power stroke of the engine during one cycle.

Power and torque depends upon the mean effective pressure of the engine.

BMEP:Brake mean effective pressure is the indication of the engine efficiency regardless of engine capacity and engine speed.

It is calculation of the engine cylinder pressure that would give the measured brake horse power.

BSFC:Brake specific fuel consumption is the ,to produce 1kilowatt of power,how much quantity of fuel required. Units :gram/kw.hr

It is typically used for comparing the efficiency of IC engines with a shaft output.

AIR FLOW RATE: Air flow rate to the engine also a factor which effects the efficiency of the engine.

IN-CYLINDER PRESSURE: It is also a pressure inside the cylinder during the 1 cycle of the IC engine.

Run the case at 1800 rpm and list down important parameters

Step-1: In the GT-ISE, Engine crank train template we can give the speed 1800 at engine speed attribute.

To have the different speeds and compare append the cases at case setup.

OUTPUTS: After Executing the results are opened in the GT-POST

AIR FLOW RATE:24.6kg/hr

BSFC(Brake specific fuel consumption):239.2 gm/kw.hr

BMEP(Brake Mean effective pressure):9.5 bar/137.4psi

Cylinder-in pressure:0.998 bar

Max Pressure:48.89 bar

2.Increase the power output at 3600 rpm by 10% (30 Marks)

INTRODUCTION: Power Output can be increased with same rpm by some of the following ways:

1)By increasing the diameter of the Bore of the engine,can increase power output.

2)By increasing the Length that is stroke of the engine, can increase power output.

3)By Increasing the compression also, the power can be increased. But If it is increased more than critical compression ratio then knocking will happen to the engine. Prolonged knocking can cause severe damge to the engine parts.

4)By increasing the mass flow rate or pressure of the intake air this can be achieved by installing the turbocharger or super charger or auxiliary blowers .

5)By Increasing the air fuel ratio that is by making the air fuel ratio leaner,power can be increased. but Here the emissions nox will increase and co will decrease

In the case of rich air fuel mixture nox will decrease and co will increase

6)ANCHOR ANGLE:It is the crank angle at which 50% of the combustion completes. With this parameter also the power and torque changes. Typically values are 8 to 12 degree

7)Duration: Durartion of combustion with out considering first 10% and last 10%. At what crank angle it completes. With this parameter also the power and torque changes. Tyically values are 25 to 35 degree

1ST CASE:BY Increasing the BORE from 86mm to 90mm

INPUTS IN GT-ISE

OUTPUTS AT GT-POST:

AT 86 mm Bore- Brake power:22.4

AT 88 mm Bore- Brake power:23.5

At 90 mm Bore-Brake power:24.7, Here the Brake power increased by approx 10%

Case2: By installing the Turbocharger or auxilary blower

Even small change in the inlet pressure of the engine, It can have big changes in the output as well as Fuel economy.

INPUTS:AT GT-ISE-Inlet pressure:1bar,1.08bar,1.16bar.

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OUTPUT: AT GT-POST

AT 1bar inlet pressure: power out put 22.4

AT 1.08bar inlet pressure: power out put 24.7

AT 1.16bar inlet pressure: power out put 27.1

By increasing the pressure inlet 1.08 bar by external prime mover, It can able to increase the power output by approx 10% i.e 24.7