How do you calculate brake specific fuel consumption?
It is the rate of fuel consumption divided by the power produced. In traditional units, it measures fuel consumption in pounds per hour divided by the brake horsepower, lb/(hp⋅h); in SI units, this corresponds to the inverse of the units of specific energy, kg/J = s2/m2.
What is BSFC formula?
The formula is: BSFC = lbs. of fuel used per hour ÷ horsepower. For example, a 300hp engine using 150 lbs./hr. of fuel would have a BSFC of 0.5.
What is BSFC and ISFC?
This effect can be explained as follows with the calculation of brake specific fuel consumption (BSFC) at a typical Federal Test Procedure (FTP) cycle operating condition, assuming a constant indicated specific fuel consumption (ISFC).
Is SFC and BSFC same?
Specific fuel consumption, abbreviated SFC, compares the ratio of the fuel used by an engine to a certain force such as the amount of power the engine produces. BSFC is used to calculate and compare the fuel efficiency of a reciprocating engine, such as an internal combustion engine.
How do you use specific fuel consumption?
Simple Method
- Formula To Estimate Maximum Engine Fuel Consumption. Gallon Per Hour (GPH) = (specific fuel consumption x HP)/Fuel Specific Weight.
- 300-hp Diesel Engine Example. GPH = (0.4 x 300)/ 7.2 = 105/7.2 = 16.6 GPH.
- 300-hp Gasoline Engine Example. GPH = (0.50 x 300)/ 6.1 = 150/6.1 = 24.5 GPH.
- Other Related Resources:
How is TSFC calculated?
The fuel mass flow rate is related to the thrust (F) by a factor called the specific fuel consumption (TSFC). The specific fuel consumption equals the mass flow rate divided by the thrust. (TSFC = mf / F ).
How is SFC calculated?
Gathering all the terms together, TSFC is the mass of fuel burned by an engine in one hour divided by the thrust that the engine produces. The units of this efficiency factor are mass per time divided by force (in English units, pounds mass per hour per pound; in metric units, kilograms per hour per Newton).
Why does BSFC decrease with engine speed?
The BSFC was found to decrease with increase in load for all tested fuels. This is due to the higher percentage increase in brake power with load as compared to the increase in fuel consumption. As speed increases the brake power increases, leading to a higher BTE.
What is the significance of specific fuel consumption?
Specific fuel consumption is the amount of fuel consumed by a vehicle for each unit of power output. A vehicle’s specific fuel consumption is more or less independent from its nitrogen oxide emissions per kilometer. The specific fuel consumption of an engine is the rate of fuel burnt to produce a unit of thrust.
Which is the correct formula for brake specific fuel consumption?
Engine torque [Nm] can also be defined function of the mean effective pressure (MEP) of the engine. Replacing (4) in (3), we can write the formula of the brake specific fuel consumption function of the mean effective pressure of the engine: The lower the brake specific fuel consumption, the more efficient the engine is.
How to reduce brake specific fuel consumption ( BSFC )?
By increasing the engine torque to 250 Nm we decrease the brake specific fuel consumption to 320 g/kWh. The excess torque (150 Nm) will be compensated by the electric machine (-150 Nm) which will run in generator mode and produce electrical energy.
Which is more efficient brake specific fuel consumption or spark ignition?
The lower the brake specific fuel consumption, the more efficient the engine is. For spark ignition (gasoline engine) the BSFC is around 250 g/kWh and for compression ignition (diesel) around 200 g/kWh.
How is brake power measured in an engine?
The power developed by an engine and measured at the output shaft is called the brake power (bp) and is given by, 2 60 π = NT bp. . . (7.1) where, Tis torque in N-m and Nis the rotational speed in revolutions per minute.
What do you mean by brake specific fuel consumption?
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. It is the rate of fuel consumption divided by the power produced.
By increasing the engine torque to 250 Nm we decrease the brake specific fuel consumption to 320 g/kWh. The excess torque (150 Nm) will be compensated by the electric machine (-150 Nm) which will run in generator mode and produce electrical energy.
How to calculate the brake power of a spark ignited engine?
Let’s take as example a 1.9 liter, 4-stroke spark ignited internal combustion engine, with the following parameters: Step 1. Calculate the area of the piston Step 2. Calculate the cylinder capacity (volume) The total engine capacity will be: Step 3. Calculate the engine brake (effective) torque Step 4. Calculate the engine brake (effective) power
Which is more efficient compression ignition or brake specific fuel consumption?
The lower the brake specific fuel consumption, the more efficient the engine is. For spark ignition (gasoline engine) the BSFC is around 250 g/kWh and for compression ignition (diesel) around 200 g/kWh. The brake specific fuel consumption of an engine is usually represented as a contour plot,…