THERMAL
ENGINEERING - I
UNIT - IV
COMBUSTION, PERFORMANCE AND SYSTEMS
SHORT QUESTIONS AND ANSWERS
BIBIN.C
, ME8493 - THERMAL ENGINEERING – I
UNIT IV
COMBUSTION, PERFORMANCE AND SYSTEMS
SHORT QUESTIONS AND ANSWERS
1. List the various parameters involved in engine performance.
1. Brake power
2. Indicated power
3. Friction power
4. Total fuel consumption
5. Specific fuel consumption
6. Thermal efficiency
7. Mechanical efficiency
8. Mean effective pressure etc.
2. Define the term brake power [Anna Univ.Apr’08& May’14]
Brake power is the useful power available at the crankshaft. It is always lesser than the indicated
power. The brake power of an IC is usually measured by means of brake mechanism.
3. Describe briefly the determination of friction power.
Friction power of an engine may be defined as the difference between indicated power and brake
power. Two kinds of loses occur in the engine. They are pumping loses and friction losses. The
pumping losses occur during suction and exhaust strokes. The friction loss is depends on the friction
between piston and cylinder walls, piston rings and cylinder walls, between crankshaft and camshaft
and their bearings etc. The friction power can be determined by using
Friction power = Indicated power – Brake power
FP = IP – BP
4. Differentiate between brake power and indicated power of an IC Engine.
[Anna Univ. Apr’03]
Indicated power is defined as the power actually developed by the engine in the engine
cylinder.
Brake power is defined as the power available at the crankshaft. It is always less than the
indicated power.
5. Differentiate between SFC and TFC in engine performance [Anna Univ. Nov’03]
SFC means Specific Fuel Consumption which is defined as the fuel consumed by the engine in kg
for producing 1 kW-hr of power.
TFC means Total Fuel Consumption which is defined as the fuel consumed by the engine in kg
for 1 hr operation.
2|B I B I N . C / A S S O C I A T E P R O F / M E C H A N I C A L / R M K C E T / U N I T - I V
ENGINEERING - I
UNIT - IV
COMBUSTION, PERFORMANCE AND SYSTEMS
SHORT QUESTIONS AND ANSWERS
BIBIN.C
, ME8493 - THERMAL ENGINEERING – I
UNIT IV
COMBUSTION, PERFORMANCE AND SYSTEMS
SHORT QUESTIONS AND ANSWERS
1. List the various parameters involved in engine performance.
1. Brake power
2. Indicated power
3. Friction power
4. Total fuel consumption
5. Specific fuel consumption
6. Thermal efficiency
7. Mechanical efficiency
8. Mean effective pressure etc.
2. Define the term brake power [Anna Univ.Apr’08& May’14]
Brake power is the useful power available at the crankshaft. It is always lesser than the indicated
power. The brake power of an IC is usually measured by means of brake mechanism.
3. Describe briefly the determination of friction power.
Friction power of an engine may be defined as the difference between indicated power and brake
power. Two kinds of loses occur in the engine. They are pumping loses and friction losses. The
pumping losses occur during suction and exhaust strokes. The friction loss is depends on the friction
between piston and cylinder walls, piston rings and cylinder walls, between crankshaft and camshaft
and their bearings etc. The friction power can be determined by using
Friction power = Indicated power – Brake power
FP = IP – BP
4. Differentiate between brake power and indicated power of an IC Engine.
[Anna Univ. Apr’03]
Indicated power is defined as the power actually developed by the engine in the engine
cylinder.
Brake power is defined as the power available at the crankshaft. It is always less than the
indicated power.
5. Differentiate between SFC and TFC in engine performance [Anna Univ. Nov’03]
SFC means Specific Fuel Consumption which is defined as the fuel consumed by the engine in kg
for producing 1 kW-hr of power.
TFC means Total Fuel Consumption which is defined as the fuel consumed by the engine in kg
for 1 hr operation.
2|B I B I N . C / A S S O C I A T E P R O F / M E C H A N I C A L / R M K C E T / U N I T - I V
