QUESTION TWO (6 points): a. In less than 10 words for each the following terms r

Question

QUESTION TWO (6 points): a. In less than 10 words for each the following terms regarding the internal combustion engines: 1. Exhaust blow down: 2. Engine Performance 3. Volumetric Efficieney 4. Mean Effective Pressure 5. Pumping work 6. Indicated Power 7. Equivalence ratio 8. Gross work 9. Valve overlap 10. Deficieney of air b. What are the following abbreviations refer to: 11.CEDC: 12. GDI: 13. HCCE: 14. EMS 15. BMT: c. Classify internal combustion engines from the point of view of (1)Basic engine design (2)Engine cycle and its operation (3) Valve location (4) Air supply (5) Cylinder arrangement QUESTION THREE (5 points): A siw-sytinder f-stroke petrol engine having a bore of 90 mm and stroke of 100 mm has a compression ratio of 7 The relative efticiency with reference to indicated thernal eficienei. SS% when indicatedmean specific fuel consump t nis 0.3 kg kWh Estimate and identify the caloritic value of the fuel and fuel consumption in kghr. Given that indicated neaneftective pressure is 8.5 bar and speed is 2500 rp.m. QUESTION FOUR (8 points): A six-cylinder, gasoline engine operates on the four stroke cycle. The bore of each cylinder is $0 mm and the stroke is 100 mm. The clearance per cylinder is 70 ce, At the speed of 4100 rpm, the fuel gm/sec. for 19.8 kghr.) and the torque developed consumption is 5.5 Calculate: (0) Brake power. (ii) The brake mean effective pressure, (ili) Brake thermal efficiency if the calorific value of the fuel is 44000 kJ/kg and (iv) The relative efficiency on a brake power basis assuming the engine works on the constant volume cycle r, = 1.4 for air. (v)Identify the loss due to friction power as the percentage of indicated power (Hint: Air standard efficiency of Otto cycle = om" 1-(1/ r,"-")) GOOD LUCK

Explanation / Answer

2)

a) Exhaust blowdown is the early opening of the exhaust valve, this results in the decrease in pressure and drop in work output during the expansion stroke.

b) Generally, engine performance is measured by considering power output, durability, economy and emissions.

c) volumetric efficiency is the ratio of fluid delivered by a piston per stroke to the swept volume.

d) MEP is a valuable measure of an engine's capacity to do work that is independent of engine displacement.

Related Questions

Navigate

• Browse (All)
• Browse Q
• Subjects

---