ข้อสอบสามัญเครื่องกล Automotive 3/2549

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4 (Automotive / ICE) 3/2549

2

1 80 (X) ( 1 )

1.

. 5 20/1

. 8 20/1

. 10 20/1

. 12 20/1

2. 2000 cc (4 ) Bore x Stoke

. 85 mm x 90 mm

. 70 mm x 80 mm

. 90 mm x 105 mm

. 100 mm x 100 mm

3. Performance Map

.

.

.

.

4. Max. Power F/A Ratio 0.75

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. F/A rich lean

.

.

.

5.

. 2

. 2

.

.

6. Squish

. Rotational flow

.

. Turbulance

.

7. Supercharger Turbo

.

.

. .

8. Valve Overlap

.

.

.

.

9.

.

.

.

.

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10. Fuel Injection

. bsfc

.

.

.

11. Common Rail

.

.

. bsfc

.

12. Pintle Hole

.

.

.

.

13. Scavenging Efficiency

. Scavenging Efficiency

.

.

. 14. E 20

.

.

.

.

15. Bio diesel

.

.

.

Esterification

.

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16. Fuel cell

. Alcohol

.

. H2

.

17. Knock

.

.

.

.

18.

. HC

.

.

.

19. Exh. Gas Recirculation Valve

.

.

.

.

20. Motor Hybrid Car

.

.

.

.

21. Hybrid Car

.

. CO2

.

.

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22. Knock SI

.

. (advance)

. (retard)

. Octane 23.

. SAE Number

. Centi stroke

. Centi poise

.

24. Multi Viscosity

.

. Single grade

.

. grade

25. Single Grade 2 Viscosity

.

.

. .

26. VI (Viscosity Index)

.

.

.

.

27.

. Hygrometer

. Thermometer

. Viscosimetor

.

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28. W

.

.

.

.

29. Additive

.

.

.

.

30.

.

.

.

.

31.

. SAE

. VI

. API

.

32. Biodiesel

. Esterification

.

.

.

33. Gasohol SI

. Octane Number

.

.

.

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34. Biodiesel CI

.

.

.

. 35. CNG

.

.

.

.

36.

. 16

.

16

.

8

.

8

37.

.

.

.

.

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38.

.

.

.

.

39.

.

.

.

.

40.

.

.

.

.

41.

.

.

.

.

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42.

.

.

.

.

43. 4 875 cc 10:1

55% ( ti=0.55 otto) 8,000 RPM

85% 90%

13:1 44MJ/kg 27OC , 1 bar, = 1.35

. 0.068 kg/MJ

. 0.078 kg/MJ

. 0.087 kg/MJ

. 0.097 kg/MJ

44. 4 4 2.5

2,800 RPM S/B = 1.03

AF = 15 44,300 kJ/kg

100% 100 kPa, 60OC

4% , = 1.35

. 434OC, 1789 kPa

. 434OC, 1826 kPa

. 489O

C, 1789 kPa. 489

OC, 1826 kPa

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45. 8:1

1 bar, 27O

C 1,170

kJ/kg Cv = 0.717 kJ/kg. K , = 1.4

. 2048OC

. 2548OC

. 3048OC

. 3548OC

46. 4 4 2.5 L

3,000 RPM 8.6:1

= 1.025 AF = 15

44,300 kJ/kg 100%

100 kPa, 60OC 4%

. 0.67 , 0.04 g

. 0.74 , 0.056 g

. 0.78 , 0.06 g

. 0.78 , 0.065 g

47. 9:1

2,800 K 9,000 kPa

460 kPa 100 kPa = 1.35

. 540OC

. 599OC

. 619OC

. 699OC

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48. 10:1 70 bar

1,680 kJ/kg 1 bar 100O

C

Cp = 1.004 kJ/kg K Cv = 0.717 kJ/kg K

. 2816OC

. 2865OC

. 2924OC

. 3065OC

49. 4 875 cc 10:1

55% ( ti = 0.55 otto) 8,000 RPM

85% 90%

13:1 44 MJ/kg 27OC , 1 bar, = 1.35

. 24.1 %

. 25.9%

. 27.9%

. 28.1%

50.

3,900 K 10,100 kPa

100 kPa , = 1.35

. 705.61OC

. 805.61OC

. 905.61O

C. 1005.61

OC

51.

.

.

.

.

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52.

.

.

.

.

53.

.

.

.

.

54.

.

.

.

.

55. ABS

.

.

. ( )

.

56.

.

.

. [ m / s2]

. 0 100 km/h 57. ( )

. 4

.

.

.

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58.

.

.

.

.

59. ( )

.

.

.

.

60.

.

.

. .

61.

.

.

.

.

62. FL = CW A P V2 CW A

P V ( )

.

. CW

.

.

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63. FR = f R G ( ) f R

G

. f R

. f R

. f R

. f R f R

64. ( )

.

.

.

. 65.

.

.

.

.

5 66 - 70 (spark ignition engine) 4 6

3 (3000 cc.) 9.5:1

2400 3.4 14.6:1

66.

. 8.2

. 8.6

. 9.0

. 9.8

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67.

. 6.9

. 7.5

. 8.0

. 8.5

68. ( )

. 49.9

. 52.6

. 55.5

. 58.8

69. ( = 0.750 kg/L)

. 13.3

. 14.0

. 16.8

. 18.6

70.

. 0.02

. 0.19

. 1.94

. 19.40

5 71 - 75 Direct Injection 2.5 (2500

cc.) 2200 140 -

8 (

850 kg/m3) 42.5 MJ/kg

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71. (brake power)

. 16.13

. 30.80

. 32.25

. 64.50

72. (Brake specific fuel consumption) g/(kW-h)

. 203.7

. 210.9

. 220.0

. 231.9

73. (Brake thermal efficiency) %

. 35.0

. 38.7

. 40.2

. 42.5

74. Brake mean effective pressure kPa

. 695.0

. 703.6

. 710.2

. 750.4

75. Indicated mean effective pressure kPa mechanical efficiency = 83%

. 837.3

. 847.7

. 855.7

. 904.1

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5 76 - 80 C8H15

21 79

(H=1, C=12, N=14, O=16)

C8H15 + 11.75 O 2 + 11.75(3.76) N 2------- 8CO2 + 7.5 H2O +

11.75(3.76) N 2

76.

. 13.80

. 14.03

. 14.53

. 15.98

77. %

. 12.57

. 13.40

. 15.33

. 19.69

78. %

. 12.57

. 13.40

. 15.33

. 19.69

79. 10 %

C8H15 + 1.1(11.75 O 2 + 11.75(3.76) N 2) 8CO2 + 7.5 H2O + 1.175 O 2 +

1.1(11.75(3.76) N 2)

. 13.80

. 14.03

. 14.53

. 15.98

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80. 10 %

%

. 1.0

. 1.4

. 1.8

. 2.2

2 1 (20 ) 1. Otto Cycle Model

(Spark Ignition Engine)

(Suction) (Compression) Isentropic

Process (PVk = C) ( - Top Dead Center)

(Spark Plug)

(Ignition) Isometric Process (V = C)

(Bottom Dead Center) Isentropic Process (PV

k = C)

(Exhaust) Isometric Process (V = C)

Air Standard Cycle Otto Cycle

Cp = 1.005 kJ/kg-K, Cv = 0.718 kJ/kg-K , k = 1.4

100 kPa 20 o C0.0023 m 3 8:1 1,500 J

(20 )

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m

m = P1V1/RT1 = 100 x 0.0023/(0.287 x (20 + 273)) = 0.0027 kg

T2

T2 = T1{v1/v2}(k-1)

= 293 x 8(1.4-1)

= 673.1 K

T3

Qin = 2Q3 = m cv (T3 T2)

T3 = 1.5/(0.0027 x 0.718) + 673.1 = 1,436.95 K

T4

T4 = T3/{v1/v2}(k-1)

= 625.47 K

Qout = 4Q1 = m cv (T1 T4) = 0.0027 x 0.718 x (293 - 625.47) = - 0.6529 kJ

Net Work W, W = Qin + Qout = 1.5 - 0.6529 = 0.8471 kJ

Cycle Efficiency = W/Qin = 0.8471 / 1.5 = 0.5647 = 56.47 %

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ข้อสอบสามัญเครื่องกล Automotive 3/2549