MODELLING AND ANALYSIS OF 12 CYLINDER DIESEL ENGINE V-TYPE

SUBMITTED BY: SUBMITTED TO:ARPIT 2015DN07 DR. SKYLAB PAULAS BHORESUDHANSHU 2015DN02 (MED)ANURAG 2015DN06PRADEEP 2015DN15NEERAJ 2015DN16(DESIGN DEPARTMENT)ABSTRACTThis project aims at modelling and analysis of 12 cylinder v diesel engine. Here model of cylinder, cylinder liner, cylinder head are designed using Catiav5 and analysis is done on Ansys15.the Analysis include steady state thermal and static structural.In the analysis the variation of the stress, deformation and thermal variation are carried out .These variations are observed using different material like aluminium alloy, structuralsteel, cast iron for cylinder ,cylinder head,cylinder liner .The results are studied and comparative study is performed.

MODELLING OF CYLINDER HEAD, CYLINDER LINER1. Actual images of cylinder head, cylinder

Fig1: Top view of the cylinder head

Fig2: Front view of cylinder head

Fig3: Front view of cylinder

Fig4: front view of cylinder head and cylinder assembly

2. CATIA modelling of cylinder, cylinder liner, cylinder head and cylinder head and cylinder assembly

Cylinder Liner

Cylinder-Liner Assembly Cylinder Head

THEORETICAL CALCULATIONSDiameter of cylinder (D) = 158mmLength of cylinder(L) = 253mmLength of stroke(l) = =220mm = 1.3924 which lies between standard limit(1.25 to 2)Reboring allowance, C = 4.368mmArea ,A = D2/4 = 18145.84 mm2Indicated mean effective pressure (Pm) = 0.4 106 PaSo, maximum pressure , Pmax = Pm 10 = 4106 PaYield tensile strength of aluminium alloy strength of aluminium alloy,(AL)yt = 280 106 PaYield tensile strength of aluminium alloy strength of structural steel (steel)yt = 250 106 PaCYLINDER :Factor of safety = 4Allowable stresses in cylinder for aluminium alloy , (AL )= (280 106)/4 = 70 106 PaAllowable stresses in cylinder for structural steel , (steel) = (250 106)/4 = 62.5 106 PaThickness of cylinder wall, t = + C For aluminium alloy = 8.882 mm For structural steel = 9.424 mmCalculated Stresses in cylinder wall is given by relationDPmax = 2 For Aluminim alloy, calulated AL = 35.57 106 PaThis is less than allowable stress in aluminium alloy.

For structural steel, calculated steel = 33.53 106 Pathis is less than allowable stresses in structural steel.

CYLINDER HEAD:Taking factor of safety = 4Thickness of cylinder head is given by relation, th = D K (constant) = 0.162For structural steel , th = 16 mmFor aluminium alloy, th = 15.20 mm

ANALYSISMaterial selected for analysis Cylinder = grey cast iron, structural steel, aluminium alloyCylinder liner = grey cast ironCylinder head = grey cast iron,structural steel,aluminium alloy1. Structural AnalysisBoundary conditionMaximum pressure = 4MPa

a. stress distribution of cylinder and cylinder liner assembly

Fig5. Aluminium alloy stress distribution

Fig6 :Stress distribution of grey cast iron

Fig7: Stress distribution of structural steelDeformation

b. Total deformation in cylinder and cylinder liner assembly

Fig8: Deformation of Aluminium alloy

Fig9: Deformation of grey cast iron

Fig10: Deformation of structural steelcylinder

c. Stress distribution of cylinder head

Fig11:Aluminium alloy cylinder head Stress distribution

Fig12: Grey cast iron cylinder head stress distribution

Fig13: Structural steel cylinder head stress distribution

d. Deformation of cylinder head

Fig14: Aluminium alloy cylinder head deformation

Fig15: Cast iron cylinder head deformation

Fig16:Structural steel cylinder head deformatio2. Thermal analysis

Boundary conditions

Maximum temperature =500Convective heat transfer coefficient for cylinder = 50Convective heat transfer coefficient for cylinder head = 10

a. Cylinder thermal analysis

Fig17: Temperature distribution of cast iron cylinder alloy

Fig18: Temperature distribution of aluminium alloy cylinder

Fig19: Temperature distribution of structural steel cylinder

b. Cylinder head thermal analysis

Fig20: Temperature distribution of grey cast iron cylinder head

Fig21: Temperature distribution of aluminium alloy cylinder head

Fig22: Temperature distribution of structural steel cylinder head

RESULT TABLE

S NO.ComponentsMaterialMax. Stress(MPa)Temp. Range(0C )

1CylinderGray cast Iron66.4500.01-482.57

2Aluminium Alloy68.3500.02-452.60

3Structural Steel63.9500.02-458.33

4Cylinder HeadAluminium Alloy66.4500.01-491.33

5Gray cast Iron68.1500.00-472.43

6Structural Steel67.4500.00-476.14

CONCLUSIONFrom the above analysis, wecan conclude in thermal analysisthat aluminium alloy proves to be a better material amongst the given materials areconcerned. The higher thermal conductivity of aluminium alloy provides fast cooling of the cylinder.As per the structural analysis is concerned the selection of material depends on the geometry of the concerned component. As we can see in the given analysis that aluminium alloy proves to be better for cylinder while structural steel gives high value of stress for the cylinder head. It has high wear resistance and high strength so can be employed to the heavy engines. It has high density so more weight.Gray Cast Iron is chosen material for the cylinder liner throughout the analysis because of its hardness and wear resistance properties.Also, Analysis shows that aluminium alloy shows the maximum deformation among the given materials and structural steel shows the last deformation

DISCUSSIONIn large engines we use a separate cylinder liner. The cylinder liner, water jacket and frame are manufactured separately and then assembled. The use of separate cylinder liner has the following advantages1. Cylinder liners are more economical because they can be easily replaced after being worn out.it is not necessary to replace the complete assembly of cylinder.2. Instead of using better grade material for all part of cylinder assembly only the cylinder liner is made of better grade wear resistant cast iron.

Cylinder and cylinder liner are usually made of grey cast iron with homogenous and grain structure .for heavy duty cylinders, nickel cast iron and nickel chromium cast iron, cast steel and aluminium alloys are used.

Reference: Design of Machine Elements by V B Bhandari. ANSYS Alberta Tutorials. Design Data Book by P. S. G.