Exam 1-B 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 Clearance Volume Specific fuel consumption Thermal efficiency Engine Compression ratio Engine angular speed

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

a- Force (F) & Pressure (p)

b- Engine Torque (Te) & Engine Capacity (Ve)

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

1- C) What are the differences between the following? ما الفرق بين التالي  أجب عن 2 فقط -
a- 4-Stroke Engines & 2-Stroke Engines

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b- Engine gross power & Engine net power

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c- Engine brake dynamometer Method & Morse test Method

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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- Indicated Power (Pi)

where:

b- Engine mechanical efficiency (hm)

where:

c- engine torque (Te)

where

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

a- Ignition spark location &

c- TDC and BDC locations

d- Valves overlapping

e- Atmospheric pressure

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

 CI engines SI engines Common features صفات مشتركة Different features صفات مختلفة Advantages المميزات

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

 Dieseling (run-on) Diesel-knock What is Causes Effects

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

i- Engine A consumes fuel as (21 kg/h) or

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

4) SI 4-strok engine, has the following specifications:

- Number of cylinder (n) is 4

- Engine swept volume (Ve) is 1600 cc

- Engine maximum brake power (Pb) is 100 kW at 5000 rpm

- Engine maximum Torque (T) is 120 Nm at 3000 rpm

- Engine compression ratio (r) is 10

- Engine Bore to stroke ratio (D/L) is 1.2

Find:
a) engine clearance volume (Vc),

b) engine brake mean effective pressure (bmep),

c) engine torque at maximum power (T),

d) engine stroke (L).