Case Study on Calibration of Basic Single Cylinder SI Engine Using GT-Power

Assignment 2:  Case study to Increase the power output at 3600 rpm by 10%

IC Engine Calibration Using GT-Power for Basic Single Cylinder Engine (SI)-Spark Ignition :

Introduction:

Requirements: GT-ISE

we need basic template to model the 1Cyl-SI engine 4 Stroke. They are 

- Inlet Environment/End Environment.

- Inlet Runner / Exhaust Runner.

- Intake Port / Exhaust Port.

- Intake Valve / Exhaust Valve.

- SI-Fuel Injector.

- Cylinders 

- CrankShaft 

important Information : 

Since temperature and air pressure varies from place to place a standard reference is necessary for comparing the testing and the documentation of chemical and physical processes.

It is always important to know the reference temperature and reference pressure.

STP - Standard Temperature and Pressure - is defined by IUPAC (International Union of Pure and Applied Chemistry) as air at 0 ^oC (273.15 K, 32 ^oF) and 10⁵ pascals (1 bar).

(Becasue this are the values we are going to consider during assinging the initial boundary condtions for Inlet Environment.)

Modelled the SI- 1Cyl Engine : GT-ISE

Q1.Run the case at 1800 rpm and list down important parameters (20 Marks)

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

Output:

Air FLow Rate:

Measurement of the rate of displacement of air or gas at a specific location.

Break Mean Effective Pressure : BMEP

The average (mean) pressure which, IF imposed on the pistons uniformly from the top to the bottom of each power stroke, would produce the measured (brake) power output. Please note that BMEP is purely theoretical and has NOTHING to do with ACTUAL CYLINDER PRESSURES.

Break Specific Fuel Consumption : BSFC

Brake-specific fuel consumption (BSFC) is a measure of the fuel efficiency of any prime mover that burns fuel and produces rotational, or shaft power. It is typically used for comparing the efficiency of internal combustion engines with a shaft output. 

                  [ BSFC = Rate of Fuel Consumption / Power Produced ]

Air flow rate = 24.6 kg/h

BMEP = 9.43 bar

BSFC = 239.2  g/kW-h

Maximum In-cylinder pressure = 48.89 bar

Q2. Increase the power output at 3600 rpm by 10%

Engine Power or Horsepower is the maximum power that an engine can put out....The Power output depends on the size and design of the engine, but also on the speed at which it is running and the laod or torque. Maximum power is acheived at relatively high speeds and at high loads.

Power = (Engine Torque x Engine Speed) / 5252.

There are three ways to increase the power output of an internal combustion engine.

             1) Increase the amount of fuel burnt in a given amount of time.

             2) Increase the temperature of the combustion process.

             3) Change the fuel itself.

             4) By increasing the A/F Ratio.

             5) Change the Stroke / Bore Details (Increase)

The first is what all about , things like increasing size, number of cylinders, compression ratios, turbo-charging, Supercharger,nitro systems, and all matter of things like timing, cam profiles, sizing and polishing of valve ports, tuning of intake and exhaust systems are trying to achieve .

The second is related to thermodynamic efficiency. The higher the temperature, the more efficient the process, and the more power produced.

The third isn’t practical for everyday vehicles,but nitro-methanol mixtures can’t be ignored as a fundamental principle.

Details of Case Study to increase power output at 3600 rpm by 10%:

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