Sample Exam 1 Internal Combustion Engines 2nd semester 1428-1429 Student Name: Student Number:

1- What are the units of the following physical quantities? ما وحدات الكميات الفيزيائية

 Density Engine swept volume Volumetric Efficiency Power Brake mean effective pressure

2-What are the relationships between the following ما العلاقة بين التالي؟

a- Force (F) & Work (W)

b- Engine Power (P) & Engine Angular velocity (w)

c- Fuel Consumption (FC) & Specific Fuel Consumption (SFC)

3- What are the differences between the following? ما الفروق بين التالي

a- Otto cycle & Diesel cycle

-

-

b- Lean mixture &  Rich mixture

-

-

c) Engine Brake Dynamometer & Motoring Test Methods

-

-

4- B) Write down the equation of the following, and identify each term أكتب معادلات المتطلبات التالية وعرف كل حد بها:

a) Engine swept volume:

Where:

b) Engine specific fuel consumption

where:

c) Engine thermal efficiency

where:

5) Write down the differences between the following (أكتب الفروق بين التالي):

 Detonation Diesel-knock What is Causes Effects

6) Write down the factors affecting combustion of SI engines(اكتب العوامل التي تؤثر على الاحتراق للبنزين) :

 The factor How it affects the combustion

7- Place the following on the chart:

a- Valves opening and closing locations

b- Ignition spark location

c- Crank shaft angles

d- The engine strokes

e- Cam shaft angles

f- Maximum pressure

8) Which car has less fuel consumption? and why?

i- Car A consumes fuel as (8 L/100 km) or

ii- Car B consumes fuel as (12 km/L)

9) An engine has four cylinders, the cylinder bore is 100 mm and the bore/stroke ratio is 1.2, maximum pressure is 5400 kPa. When the engine is tested with and electric swinging field dynamometer it gives the following readings: brake power reading was 92 kW at 5400 rev/min, and when it is motoring tested at the same engine speed the reading was 8.5 kW. Find:
a) engine swept volume,
b) engine friction power,
c) engine mechanical efficiency,

d) engine torque at 5400 rev/min,

e) the maximum force on the piston head.
f) the quantity of air entering the engine if the volumetric efficiency is 85%