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 of

Technology and Education

Faculty of Vehicle and Energy Engineering

Department of Internal Combustion

Engine

PROJECT MAZDA 6 Subject: INTERNAL COMBUSTION ENGINE CALCULATION

Lecturer: Ly Vinh Dat

1 Engine parameters 5

2 Report content 5

3 Curves 5

CHAPTER 1: THERMAL CALCULATE 6

2.1 Parameters of Mazda 6 6

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 Combustion Process 12

2.3.3.1 Theoretical air requirement in kmoles needed for the combustion of 1 kg of fuel (M0) 12

2.3.3.2 The actual quantity of air participating in combustion of 1 kg of fuel (M1) 12 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

2.3.4 Expand procces 14

2.3.4.1 Preexpansion in the case of heat added at constant pressure( ρ) 14

2.3.4.2 After expansion (ε) 14

2.3.4.3 The expansion mean polytropic index (n2) 14

2.3.4.4 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 Piston displacement 20

2 Piston speed 21

3 Piston acceleration 22

II Dynamics of the crankshaft - connecting rod mechanism 23

1.Pneumatic force 23

2.Inertial force of moving parts 24

1 Engine parameters

Angle of open(close) intake(exhaust) valve

2 Report content

Associate Prof Ly Vinh Dat

CHAPTER 1: THERMAL CALCULATE

2.1 Parameters of Mazda 6

2.2 Choose parameter for thermal calculate

2.2.1 Intake Air Pressure (P 0 )

thinner.At altitude of sea level:

Intake Air Temperature (T 0 )

Intake air temperature depends on average temperature where the vehicleoperated.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

2.2.3 The Compressor Outlet Air Pressure (P ) k

Non-Turbocharge 4-Stroke engine:

2.2.4 The Compressor Outlet Air Temperature (T ) k

2.2.5 Pressure At The End Of Intake (P a )

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

Pa= 0,08104 MN/m2

2.2.6 Pressure Of Sesidual Gases (P r )

(0,11÷0,12) MPa

2.2.7 Temperature Of Sesidual Gases (T r )

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

2.2.8 Fresh 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 ( )    

i

Combustion chamber volume:

The piston stroke in mm

CHAPTER 2: CALCULATION OF PISTON

DYNAMICS AND CRANKSHAFT - CONDUCTING

ROD STRUCTURE DYNAMICS

I Kinetics of the piston

1 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 andthe centerline of the cylinder

L

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

to its initial position (ĐCT)

With:

λ

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

= 0.17(𝑚)

𝜆 0,25

2 2Using MATLAB, we can draw the piston displacement graph as follows:

Average piston speed:

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

II Dynamics of the crankshaft - connecting rod mechanism

1 Pneumatic force

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

Exhaust procces: α = [540°, 720°]

pkt = prThe 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)

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

%Va = Vd+Vc

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

X2 = R*(1-cosd(a2)+(lamda/4)*(1-cosd(2*a2)));V2 = X2*Sp+Vc;

% QUA TRINH NEN

a3 = linspace(180,350,1000);

X3 = R*(1-cosd(a3)+(lamda/4)*(1-cosd(2*a3)));V3 = X3*Sp+Vc;

% Diem z”

X41 = R*(1-cosd(375) + (lamda/4).*(1-cosd(2.*375)));V41 = X41*Sp + Vc;

% QUA TRINH GIAN NO

a6 = linspace(375,500,1000);

X6 = R*(1-cosd(a6) + (lamda/4).*(1-cosd(2.*a6)));V6 = X6.*Sp + Vc;

% QUA TRINH THAI

a8 = linspace(580,720,1000);

X8 = R*(1-cosd(a8) + (lamda/4).*(1-cosd(2.*a8)));V8 = X8*Sp + Vc;

P8 = linspace(Pr,Pr,1000);

P2 = Pa.*(Va./V2).^n1;

% qua trinh chay - gian no

% hieu chinh doan c'-c"

a2hc = linspace (345,360,100);

x2hc = R.*((1-cosd(a2hc))+(lambda/4).*(1-cosd(2.*a2hc)));V2hc = x2hc*Fp + Vc;

%xac dinh diem b'''

hold ;on

plot (adh,Sp,'k' 'linewidth', ,1.5);

axis([0 360 0 0.11]);

legend('SpI' 'SpII' 'Sp', , );

legend('VpI' 'VpII' 'Vp', , );

legend('JpI' 'JpII' 'Jp', , );

grid ;on

clc;