Project mazda 6 subject internal combustion engine calculation

CHAPTER 2: CALCULATION OF PISTON DYNAMICS AND CRANKSHAFT - CONDUCTING ROD STRUCTURE DYNAMICS .20I.. Intake Air Temperature T0Intake air temperature depends on average temperature where t

Ho Chi Minh City University ofTechnology and Education

Faculty of Vehicle and Energy EngineeringDepartment of Internal Combustion

PROJECTMAZDA 6

Subject: INTERNAL COMBUSTION ENGINE CALCULATIONLecturer: Ly Vinh Dat

2.2 Choose parameter for thermal calculate 6

2.2.1 Intake Air Pressure (P0) 6

2.2.2 Intake Air Temperature (T0) 7

2.2.3 The Compressor Outlet Air Pressure (Pk) 7

2.2.4 The Compressor Outlet Air Temperature (Tk) 7

2.2.5 Pressure At The End Of Intake (Pa) 7

2.2.6 Pressure Of Sesidual Gases (Pr) 7

2.2.7 Temperature Of Sesidual Gases (Tr) 7

2.2.8 Fresh Charge Preheating Temperature (∆T) 8

2.2.9 1 Factor 8

2.2.10 2 Factor 8

2.2.11 t Factor 8

2.2.12 Heat gain coefficient at point Z ξz 9

2.2.13 Heat gain coefficient at point B ξb 9

2.2.14 ir residue coefficient α 9

2.2.15 Choose the coefficient to fill the work graph 𝝋d 9

2.2.16 Turbo ratio 9

2.3 Thermal calculate 10

2.3.1 Intake Process 10

2.3.1.1 Volumetric effciency (ηv) 10

2.3.1.2 Coefficient of residual gases (𝜸ᵣ) 10

2.3.1.3 Temperature at the end of induction (Ta) 10

2.3.2 Compress Process 10

2.3.2.1 The mean molar specific heat of the air 10

2.3.2.2 The mean molar specific heat of residual gases at the the end of compression 11

2.3.2.3 The mean molar specific heat of the working mixture 11

The compression means polytropic index n1

2.3.2.5 The pressure at the end of compression process 11

2.3.2.6 The temperature at the end of compression process (Tc) 11 2.3.3.3 The tottal amount of combustion products (M2) 12

2.3.3.4 The theory molecular change coefficient of combustible mixture (β0)13 2.3.3.5 The actual molecular change coefficient of combustible mixture (β) 13 2.3.3.6 The molecular change coefficient of combustible mixture points Z (βZ) 13

2.3.3.7 Chemically incomplete combustion of fuel 13

2.3.3.8 The molar specific heat of the working mixture at point Z 13

2.3.3.9 The temperature at the end of combustion process 14

2.3.3.10 The pressure at the end of combustion process 14 The temperature at the end of expansion process 15

2.3.4.5 The pressure at the end of expansion process 15

2.3.4.6 Test for temperature of residual gases 15

2.3.4.7 Error of residual gases 15

2.4 Calculate typical parameters of the cycle 15

2.4.1 Calculated average indicated pressure pi' 15

2.4.2 Actual average indicated pressure 15

2.4.3 Mechanical loss pressure 16

2.4.4 Mean effective pressure 16

2.4.5 Mechanical efficiency 16

2.4.6 Indicator efficiency 16

2.4.7 Effective (thermal) efficiency 16

2.4.8 The indicator specific fuel consumption 16

2.4.9 The effective specific fuel consumption 16

2.4.10 Cylinder-size effects 16

3 Curves 19

CHAPTER 2: CALCULATION OF PISTON DYNAMICS AND CRANKSHAFT - CONDUCTING ROD STRUCTURE DYNAMICS 20

I Kinetics of the piston 20

1.Engine parameters

Angle of open(close) intake(exhaust) valve

2.Report content (Sign and full name)

Associate Prof Ly Vinh Dat

CHAPTER 1: THERMAL CALCULATE 2.1 Parameters of Mazda 6

2.2 Choose parameter for thermal calculate

2.2.1Intake Air Pressure (P0)

thinner.At altitude of sea level:

Intake Air Temperature (T0)

Intake air temperature depends on average temperature where the vehicle operated.It’s difficult for vehicle designed to operated where the range of temperature variation during the day is large.

South Viet Nam is belonging tropic region so average temperature during

2.2.3The Compressor Outlet Air Pressure (P )k

Non-Turbocharge 4-Stroke engine:

2.2.4The Compressor Outlet Air Temperature (T )k

2.2.5Pressure At The End Of Intake (Pa)

Intake air pressure at the end of intake stroke is always smaller than intake pressure before coming through intake valve because volume loss in intake manifold and throttle.

Pa= 0,08104 MN/m2

2.2.6Pressure Of Sesidual Gases (Pr)

(0,11÷0,12) MPa

2.2.7Temperature Of Sesidual Gases (Tr)

In ICEC, usually take T at the end of exhaust stroke.

Value of Tr depends on many factor as compress ratio , air equivalence𝜀 (), speed of crankshaft,

Take Tr = 970 oK

2.2.8Fresh Charge Preheating Temperature (∆T)

During the cylinder filling process, the temperature of a fresh charge

dependent on the arrangement and construction of the intake manifold, cooling system, use of a special preheater, engine speed and supercharging Increased temperature improves fuel evaporation, but decreases the charge density, thus affecting the engine volumetric efficiency These two factors in opposition resulting from an increase in the reheating temperature must be taken into account in defining the value of ∆T.

Air equivalence ratio ( )    

The coefficient α greatly affects the combustion process: For internal combustion engines, calculation.

The heat usually has to be calculated in maximum power mode, the air residue coefficient is selected in the range is given in the following table:

It is the ratio between the pressure of the gas mixture in the cylinder at the end of combustion and too compressor.

The λ value is usually in the following range: Gasoline engine: λ = 3.00 ÷ 4.00

Take λ = 3.00

i

The engine displacement volume in litres is determined by the effective, power, engine speed and effective pressure:

𝑉 = 30 N𝑟 e=30.4.90= 0,681 𝑑𝑚 , 3 (𝑙í𝑡)

Q

Combustion chamber volume:

CHAPTER 2: CALCULATION OF PISTONDYNAMICS AND CRANKSHAFT - CONDUCTING

ROD STRUCTURE DYNAMICS

I.Kinetics of the piston1 Piston displacement

Động Dynamic diagram of piston - crankshaft - connecting rod mechanism of the concentric structure

x – Displacement of piston calculated from TDC according to crankshaft rotation angle

L – Connecting rod length

R – Rotation radius of the crankshaft α – Rotation angle of the crankshaft

β – Angle of deviation between the centerline of the connecting rod and the centerline of the cylinder

L

Applying the approximate formula to the concentric structure, we have:

to its initial position (ĐCT).

𝜆: Structural parameters of the engine Choose λ = 0,30

Differentiating the displacement expression over time will yield the piston motion speed equation:

Average piston speed:

Differentiating the velocity expression with respect to time, we have the piston acceleration formula:

Using MATLAB, we can draw the piston displacement graph as follows:

II.Dynamics of the crankshaft - connecting rod mechanism1 Pneumatic force

on the pressure values available in the P – indicated work graph and redraw according to the crankshaft rotation angle 

Expansion process:  goes from the end point of the combustion process on the indicator diagram.

pkt = p (z𝘍𝘍 Vz𝘍𝘍 n2

)

Exhaust procces: α = [540°, 720°] pkt = pr

The correction segments of the pkt pneumatic force graph are similar to those on the P - V indicator work graph, but instead of adjusting according to V, the

2 Inertial force of moving parts

Mass of the crankshaft - connecting rod mechanism

(aluminum alloy piston)

Mass of the crankshaft (rotating parts)

Mass of the connecting rod group

To simplify the calculation and its error is not significant, we choose the method of using mass instead The replacement volume is calculated according

Inertial force (straightening) of a reciprocating mass

pj = −m R ω t 2 (cos α( ) + λ cos( )) (2α MN/m2), with follow each process similar 

Inertial force (centrifugal force) of rotating mass pk

pk = −m R ωr 2(MN/m2)

Total force p1 is the combined force of atmospheric force and inertial force calculated according to the formula:

p1 = p + pkt j

%Va = Vd+Vc

Fp = (pi*(D^2))/4;

% qua trinh chay - gian no % hieu chinh doan c'-c"

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