17/08/26 Mon 14:00pm
- Internal Combustion Engines: Brake Power (BP) is the actual usable power available at the engine’s crankshaft or output shaft. It is calculated as the difference between the Indicated Power (power developed in the cylinder) and Frictional Power (power lost to internal friction). It is measured using devices like dynamometers and is the standard metric for evaluating an engine’s performance efficiency ().
Volumetric Efficiency in an internal combustion engine design refers to the efficiency with which the engine can move the charge of fresh air into and out of the cylinders. It also denotes the ratio of equivalent air volume drawn into the cylinder to the cylinder’s swept volume.5 This equivalent volume is commonly inserted into a mass estimation equation based upon Boyle’s Gas Law. When VE is multiplied by the cylinder volume, an accurate estimate of cylinder air mass (charge) can be made for use in determining the required fuel delivery and spark timing for the engine.
Brake Specific Fuel Consumption BSFC
- BSFC Decreased as the ethanol percentage increased.
- As the engine speed increases reaching 600 RPM, the BSFC decreases reaching its minimum value.
Types of air-fuel mixture
- Rich (required at cold start / high torque demand)
- Lean
- Stoichiometric / chemical equivalent