SI Engine Case Study - IC-Engine Calibration Using GT-Power and GT-Suite.

IC-Engine Calibration Using GT-Power and GT-Suite

Assingment:3 (SI Engine Case Study)

Aim : To select SI engine model, collect the details of the engine specifications and run the simulations for Maximum Power and Maximum Torque condition.

To Show:

• Compare the obtained results and list the important parameters.
• Post process and upload the obtaned data of the following;

> PV and Log PV diagram.

> Cylinder Pressure and Burn Rate.

> Valve Mass Flow and Pumping Loop.

Simulation :

Engine Specifications:-

1. Displacement = 1497cc
2. Max.power = 117.6 bhp i.e. 87.7 kW @ 6600rpm
3. Max.Torque = 145Nm @ 4600rpm
4. Number of cylinders = 4
5. Valves per cylinder = 4
6. Valve cnfiuration = SOHC
7. Type of cooling = Water cooled
8. Total Valves = 16
9. Bore * stroke = 73.0 * 89.4 mm

In order to import the Engine Model for SI Engine > navigate to Examples > go to Engine_1D_Gas_Exchange_Combustion > select "Gasoline" > double tap on "SI_4cyl_GDI

" > select "SI_4_CYL_GDI.gtm". This opens the modelin GT suit.

Engine Model

Initially run the engine simulation by only changing the RPM as per our engine specification. In the fst case by only changing the rpm we can check the results and then change various parameters.

Results:

From the above results, the Brake Power is 103kW and the Torque is 192.9 N-m. Hence we can conclude that these results doesn't match our required engine specifications, so we need to modify few required parameters from the engine model and obtained the matched configuration of the required engine.

As we know all the parameters are equally important to produce good and effective power and torque, so adjustig the values correctly ensures optimum results.

In the second phase, keep the Engine Speed as constant i.e. 6600rpm and 4600rpm and modify the values of bore and stroke.

Results:

From the above results, the Brake Power is 93.5kW and the Torque is 145.9 N-m. Hence it is observed that the value of Torque is almost close to the desired torque, but the power is a bit more compare to engine specs.

In order to match our requirement change the value of cam angle and check if the values go close to the required outputs.

Initially the cam angle is 225 and change it to 224 and check the compare the obtained result. As we have changed bore and stroke, the valve timing should also be adjusted and it will reduce the power and torque.

Results:

From the above results, the Brake Power is 92.4kW and the Torque is 145.7 N-m. Now we can say that the results are much more closer to the required specifications.

Now also change the compression ratio and check if the values are close to the required values. Initially the compression ratio is 9.5 and now chaange it to 9 and check for the resultant power and torque.

Result:

From the above results, the Brake Power is 90.6kW and the Torque is 144.0 N-m. Now we can say that the results are much more closer to the required specifications. To capture the exact result, we need complete details of engine parameters.

As results are close enough we can consider these values to compare the actual engine specifications.

Plots:-

LogP- LogV Diagram:

InCylinder Pressure:

Burn Rate:

Valve Mass Flow Rate :

Pumping Loop :

Comparing parameters at 6600rpm and 4600rpm:

LogP- LogV Diagram:

InCylinder Pressure:

Burn Rate:

Pumping Loop :

Conclusion:

Engine specifications data is obtained and SIengine model is created. Here the simulations are done for MaximumPower and Maximum Torque Condition. On running the simulations different parameters are modified to get desired output and resultsare compared for two different rpm. Also various plots like PV and log PV diagram, incylinder pressure , burn rate plot , valve mass flow rate , pumping loop etc are plotted.