Internal Combustion Engines	Sample Exam 2        2nd semester 1428-29
Student Name:	Student Number:      -      -        (   )

1) A- A low speed diesel engine operating on the constant pressure cycle has a compression ratio of 12:1. Air temperature and pressure before compression are 27^oC and 130 kN/m² respectively. The temperature after combustion was 1027^oC, g = 1.4. The volume at the beginning of the compression was 480 cm³.

 

Process 1-2  (                                        )

V₁ / V₂ = r = 12

T₁ = 27 + 273 = 300 K

	P (kN/m2)	V (cm3)	T (K)
Point 1	130	480
Point 2	*	*	*

 

 

 

 

 

 

 

 

 

 

Process 2-3 (                                    )

T₃ = 1027 + 273 = 1300 K

	P (kN/m2)	V (cm3)	T (K)
Point 2	*	*	*
Point 3	#	#	#            1300

 

 

 

 

 

 

 

 

 

 

 

 

Process 3-4 (                                  )

	P (kN/m2)	V (cm3)	T (K)
Point 3	#	#	#           1300
Point 4	“	“          480	“

 

 

 

 

 

 

 

 

 

 

Process 4-1 (                                       )

	P (kN/m2)	V (cm3)	T (K)
Point 4	“	“          480	“
Point 1	*            130	*         480	*

 

 

 

 

 

 

 

 

 

 

 

1) B- Sketch a pV diagram of the cycle and show the W_in , W_out , Q_in , and Q_out.

 

C- Find the volume of the cylinder V_s.

 

D- Write down the equation for the engine efficiency.

 

 

 

 

 

 

 

 

1) C- Complete the table below:

 

	Process name
1-2
2-3
3-4
4-1

 

 

2- What is meant by the following:

 

PPM

 

SMOG

 

DOHC

 

SIE

 

3) A- Complete the following table (types of engines)

 

Engine type	1	2
Engine cooling	Water cooled engines	Air cooled engines

 

B-   complete the table

	Advantages	Disadvantages
Water cooled engines	- -	- -
Air cooled engines	- -	- -

 

 

4- What are the car pollutants?

 

Pollutants	Car Sources	Effects