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

1 A) What are the units of the following physical quantities? ما وحدات الكميات الفيزيائية التالية

 Engine Weight Engine FC Engine mechanical efficiency Engine Net Power Brake mean effective pressure

1 B) What are the relationships between the following ما العلاقة بين التالي؟ - أجب عن 2 فقط

a- Force (F) & Torque (T)

b- Indicated power (Pi) & Brake power (Pb)

c- Mechanical efficiency (hm) & Friction Power (Pf)

1 C) What are the differences between the following? - ما الفروق بين التالي أجب عن 2 فقط

a- SI engines & CI engines

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b- Fuel consumption & Specific fuel consumption

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c- Morse test & motoring test methods

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2 A)- Write down the equation of the following, and identify each term اكتب معادلات المتطلبات التالية وعرف كل حد بالمعادلة-  أجب عن 2 فقط

a- Engine compression ratio (r)

where:

b- Engine volumetric efficiency (hv)

where:

c- Brake Power (Pb)

where

2 B)  Place the following on the chart:  وضح على الشكل المطلوبات التالية

a- Ignition spark location

b- Power stroke

c- TDC and BDC locations

d- Clearance volume

e- Cylinder volume

3 A) Complete the following table showing the difference between the following اكمل الجدول التالي مبين الفرق بين التالي:

 Air/fuel mixture Rich Poor Air/fuel ratio Exhaust gases components Advantages

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

 Detonation Pre-ignition What is Causes Effects

3 C) Which engine hase less fuel consumption? and why?

i- Engine A has brake power of 120 kW, and SFC is 0.3 kg/(kW h)

ii- Engine B consumes fuel as (32 L/h) if fuel density ρ = 0.7 kg/L

4) 4-stroke engine has a swept volume (Ve) of 1.6 L and a compression ratio (r) of 8. The number of cylinder (n) is 4 and the bore diameter (D) is 8.5 cm. The imep is 1120 kPa, at 3000 rpm

a- Find the cylinder swept volume (Vs).

b- Find the clearance volume (Vc).

c- Find the engine stroke (L).

d- Find the engine indicated power (Pi)