Let's calculate each of the required values step by step.

Given:

• Number of cylinders ($n$) = 6
• Engine speed ($N$) = 2400 rpm
• Bore ($D$) = 90 mm = 0.09 m
• Stroke ($L$) = 120 mm = 0.12 m
• Indicated Mean Effective Pressure (IMEP) = 560 kPa = 560,000 Pa
• Torque ($T$) = 120 Nm

Formulas:

1. Brake Power ($P_b$): $P_b = \frac{2 \pi N T}{60}$ where $N$ is in rpm and $T$ is in Nm.

2. Indicated Power ($P_i$): $P_i = \frac{n \times P_m \times L \times A \times N}{2}$ where:

   • $P_m$ is the IMEP
   • $A$ is the area of the piston = $\frac{\pi D^2}{4}$

3. Friction Power ($P_f$): $P_f = P_i - P_b$

4. Efficiency of Engine ($\eta$): $\eta = \frac{P_b}{P_i} \times 100$

Calculations:

a) Brake Power ($P_b$):

$P_b = \frac{2 \pi \times 2400 \times 120}{60} \, \text{Watt}$

Let's calculate this:

$P_b = \frac{2 \times 3.1416 \times 2400 \times 120}{60}$

$P_b \approx 30159.29 \, \text{Watt} \approx 30159 \, \text{Watt}$

Answer 1: 30159 Watt

b) Indicated Power ($P_i$):

$A = \frac{\pi \times (0.09)^2}{4}$ $A \approx 0.00636 \, \text{m}^2$

Now,

$P_i = \frac{6 \times 560000 \times 0.12 \times 0.00636 \times 2400}{2}$

Let's calculate this:

$P_i \approx 30829.82 \, \text{Watt}$

Answer 2: 30829.8 Watt

c) Friction Power ($P_f$):

$P_f = P_i - P_b = 30829.8 - 30159$

Let's calculate this:

$P_f \approx 670.8 \, \text{Watt}$

Answer 3: 670.8 Watt

d) Efficiency of Engine ($\eta$):

$\eta = \frac{P_b}{P_i} \times 100 = \frac{30159}{30829.8} \times 100$

Let's calculate this:

$\eta \approx 97.8 \%$

Answer 4: 98 %

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Would you like more details or have any questions?

Related Questions:

1. What are the implications of a high friction power in an engine?
2. How does the IMEP affect the indicated power in an engine?
3. Why is the efficiency of a 4-stroke engine typically lower than 100%?
4. What is the relationship between engine torque and brake power?
5. How would increasing the engine bore affect the engine’s power output?

Tip:

Regular maintenance, such as proper lubrication, can reduce friction power and improve engine efficiency.