Calculate the indicated horsepower of the following engine: 5 cylinders, a stroke length of 0.77 feet, a bore of 3.8 inches, operating at 3090 rpm , and has an indicated mean effective pressure (IMEP) of 960 psi per cylinder.

Question

UpStudy AI · Accepted Answer

To calculate the indicated horsepower (IHP) of the engine, we can use the following formula:

$$
\text{IHP} = \frac{(N \times L \times A \times P_{IMEP})}{33,000}
$$

Where:
- $$ N $$ = number of cylinders
- $$ L $$ = stroke length in feet
- $$ A $$ = area of the piston in square feet
- $$ P_{IMEP} $$ = indicated mean effective pressure in pounds per square foot (psf)

### Step 1: Convert the bore from inches to feet
The bore is given as 3.8 inches. To convert this to feet:

$$
\text{Bore in feet} = \frac{3.8 \text{ inches}}{12} = 0.31667 \text{ feet}
$$

### Step 2: Calculate the area of the piston (A)
The area of the piston can be calculated using the formula for the area of a circle:

$$
A = \pi \left(\frac{D}{2}\right)^2
$$

Where $$ D $$ is the bore in feet. Thus,

$$
A = \pi \left(\frac{0.31667}{2}\right)^2 \approx \pi \left(0.158335\right)^2 \approx \pi \times 0.025036 \approx 0.0786 \text{ square feet}
$$

### Step 3: Convert IMEP from psi to psf
The indicated mean effective pressure (IMEP) is given as 960 psi. To convert this to pounds per square foot (psf):

$$
P_{IMEP} = 960 \text{ psi} \times 144 \text{ (since 1 psi = 144 psf)} = 138240 \text{ psf}
$$

### Step 4: Substitute values into the IHP formula
Now we can substitute the values into the IHP formula:

$$
\text{IHP} = \frac{(5 \times 0.77 \times 0.0786 \times 138240)}{33,000}
$$

Calculating the numerator:

$$
5 \times 0.77 \times 0.0786 \times 138240 \approx 5 \times 0.77 \times 0.0786 \times 138240 \approx 5 \times 0.077 \times 138240 \approx 5 \times 10600.8 \approx 53040.4
$$

Now, divide by 33,000:

$$
\text{IHP} \approx \frac{53040.4}{33000} \approx 1.606 \text{ horsepower}
$$

### Final Result
The indicated horsepower (IHP) of the engine is approximately **1.61 horsepower**.
The indicated horsepower of the engine is approximately 1.61 horsepower.

Calculate the indicated horsepower of the following engine: 5 cylinders, a stroke length of 0.77 feet, a bore of 3.8 inches, operating at 3090 rpm , and has an indicated mean effective pressure (IMEP) of 960 psi per cylinder.

Real Tutor Solution

Answer

Solution

Beyond the Answer

Related Questions

Latest Engineering Questions