ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 25 3D MODELLING OF A RECONDITIONED PISTON OF A SINGLE-CYLINDER FOUR-STROKE DIESEL ENGINE BY USING SOLID WORKS SOFTWARE F.O Isaac1, O. Obodeh2 and O. Ighodalo2 1Faculty of Engineering, Department of Mechanical Engineering, Edo State University Uzairue. 2Edo State, Nigeria, 2Faculty of Engineering and Technology, Department of Mechanical Engineering, Ambrose Alli University, Ekpoma. Edo State, Nigeria Corresponding Author’s Email: isaac.oamen@edouniversity.edu.ng Article History: Received 11 February 2023; Revised 03 March 2023; Accepted 28 March 2023 ABSTRACT: This paper gives the possibility of modelling a reconditioned piston of a single-cylinder four-stroke diesel engine using the ZS1115NM diesel engine specifications. Due to the upsurge of counterfeit spare parts in the market, meeting the original equipment manufacturer (OEM) standards requires a reconditioning process. The reconditioned piston is a thermal barrier coated one with a ceramic material that enables it to withstand high gas combustion temperatures without cracking. A piston converts thermal energy to mechanical energy in an internal combustion engine (ICE). The methodology includes sizing and modelling of the conventional piston, topcoat and bond-coat layers and finally assembling them to get a reconditioned piston using SolidWorks Computer-Aided Design (CAD) software. The material chosen for the piston is an aluminum alloy designated as A2618, due majorly to its high coefficient of thermal expansion (CTE) which enables the piston to withstand high thermal stress without cracking or failing. The ceramic material chosen is a 7.5% yttria-stabilized zirconia which is the topcoat with low thermal conductivity and a high coefficient of thermal expansion (CTE) on a bond-coat metallic material called Nickel Chromium Aluminum Cobalt Yttria which are applied by plasma sprayed method on the crown of the substrate. The chosen thickness from the literature of the topcoat layer is 0.35 mm and that of the bond-coat layer is 0.15 mm. Also, from the literature, the major reason for the thermal barrier- coating (TBC) of a diesel engine piston crown using a ceramic material was to improve its performance. KEYWORDS: 3D-modelling; Original Equipment Manufacturer; SolidWorks Software; 7.5% Yttria- stabilized Zirconia; Nickel Chromium Aluminum Cobalt Yttria 1.0 INTRODUCTION The thermal barrier-coatings (TBCs) are advanced ceramic materials applied on metallic surfaces of aero-engine, turbine and spark and compression-ignition engine parts (cylinder liner, cylinder head, valves, piston crown, etc.), which work at very high temperatures [1]. Coatings help to insulate metallic parts from heavy and excessive heat loads using thermally insulating materials which withstand reasonable temperature difference between the combustion chamber and coating surfaces. This results to high operating temperatures on the metallic or component surfaces. Coatings also reduce the problems of oxidation and thermal fatigue in order to extend the life span of the machine components. Modern coating systems behave as barriers to heat transfer through metallic surfaces so as to protect engine parts from oxidation and hot corrosion [2,3]. The piston in an internal combustion engine (ICE) is a round piece of metal that converts the rotary motion of the crank-shaft into a reciprocating motion in the cylinder and exerts a force on the air-fuel mixture contained in the cylinder [4]. Piston has Journal of Mechanical Engineering and Technology (JMET) 26 ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 compression and oil control rings preventing oil from entering the combustion-chamber including the fuel air from mixing with the oil [5]. Most fitted pistons in engine cylinders have piston rings [6]. Two or more compression rings are acting as seals or barriers between the piston and cylinder-wall. There are also one or two oil control-rings below the compression-rings (Figure 1). The piston head may be flat, bulged or otherwise shaped. Pistons which are either forged or cast have rounded shapes [5]. The preferred common materials for petrol and diesel engine pistons are aluminium alloys because they possess high thermal conductivity, low density, simple machinability, high- reliability, simple fabrication processes and very good recycling-characteristics [7]. Figure 1: The different parts or elements of the piston The single-component coating has not satisfied some multifunctional requirements of some engine parts. As a result, a complex thermal-barrier-coating structure was introduced. Research from the 1970s focused on a preferred coating system that comprises three separate layers on the substrate to achieve long-term improvement in the control of oxidation and corrosion at high temperatures [8,9]. Adnan et al. [13] conducted a test on a single-cylinder, indirect injection Ricardo E6-MS/128/76 type diesel engine. They coated the cylinder head, valves and piston with MgO–ZrO2 layer having 0.35 mm thickness on a NiCrAl bond-coat layer also having 0.15 mm thickness. They discovered that in low-heat-rejection (LHR) diesel-engine the NOx emissions were reduced by about 40% and the brake specific fuel consumption (BSFC) also reduced by about 6% compared to the conventional engines when injection timing was retarded to 3400 crank-angles before top dead centre (TDC) to that of a conventional engine. Ekrem et al. [14] compared a conventional engine with a LHR engine. They used MgZrO3 as a coating material for the diesel piston and CaZrO3 for the cylinder head and valves. The piston was coated with MgZrO3 having a thickness of 350 μm on a NiCrAl bond-coat- layer with 150 μm thickness. The results obtained showed that the combustion gas temperature for the LHR engine was increased by approximately 65 0C while the BSFC and particulate emissions were reduced by about 6% and 40%, respectively as compared to a conventional engine. Rohini and Prema [11] reviewed thermal barrier-coating (TBC) on the same diesel engine performance to improve thermal efficiency by reducing 3D Modelling of a Reconditioned Piston of a Single- Cylinder Four-Stroke Diesel Engine by Using Solid Works Software ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 27 specific fuel consumption (SFC) and exhaust emissions [15,16]. They were able to make a comparison between a standard diesel engine and a low-heat-rejection (LHR) engine. Experimental results from various researchers show improvement in efficiency and rate of specific fuel consumption. Navin et al. [16] analyzed the performance and emission of a thermal barrier-coated engine by using palm oil biodiesel and diesel as fuels. They prepared TBC using a series of a mixture consisting of different blend ratios of yttria- stabilized zirconia (Y2O3.ZrO2) and aluminium oxide-silicon oxide (Al2O3-SiO2) via plasma spray coating method. Their experimental results revealed the mixtures of TBC with 60% Y2O3.ZrO2 + 40% Al2O3-SiO2 had excellent nitrogen oxide (NO), carbon monoxide (CO), carbon dioxide (CO2), and unburned hydrocarbon (UBHC) reductions when compared with other blend-coated pistons [12,17-18]. Plasma spray-coating system is the process whereby a powder feedstock is injected into a high-temperature plasma-jet where finely divided metallic and non-metallic materials are deposited in a molten or semi-molten state on a prepared substrate [19,20]. It is used as an effective and economical method for producing ceramic-coatings on metallic- substrates and production of bulk-powders from spheroidization [21]. The plasma spray-coating system is shown in Figure 2 while the spraying-gun system is displayed in Figure 3. The system consists of a power unit, gas supply unit, spraying-gun, powder- supply unit, cooling-system and control unit [20,22]. Figure 2: Plasma spray-coating system The plasma spray-coating is the most widely accepted method of coating [20,23]. Figure 3 shows some coated piston tops. Journal of Mechanical Engineering and Technology (JMET) 28 ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 (a) (b) Figure 3: Ceramic coated piston tops 2.0 METHODOLOGY 2.1 Materials The three (3) materials used for the 3D modelling were a metal substrate called the aluminium alloy piston A2618, a metallic bond-coat of thickness 0.15 mm called the Nickel Chromium Aluminium Cobalt Yttria (NiCrAlCoY) with a chemical composition of Bal Ni, 17.5% Cr, 5.5% Al, 2.5% Co, 0.5% Y2O3; and ceramic topcoat also of thickness 0.35 mm called the Yttria Stabilized Zirconia (7.5% Y2O3-ZrO2) [22]. This paper is part of our PhD work [22]. 2.2 Methods 2.2.1 The design of the piston elements Figure 4 shows the cross-sectional view of conventional or uncoated piston [22]. Figure 4: Cross-section of the model conventional piston 3D Modelling of a Reconditioned Piston of a Single- Cylinder Four-Stroke Diesel Engine by Using Solid Works Software ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 29 2.2.1.1 Design of the thickness of the piston head or crown, tC According to Grashoff’s formula, the piston head thickness tC is given by, 𝑡𝐶 = √ 3𝑝𝑚𝑎𝑥𝐷 2 16𝜎𝑦 (1) where 𝑝𝑚𝑎𝑥 is the maximum gas pressure (Pa), D is the cylinder bore or outside diameter of the piston (m), 𝜎𝑦 is the permissible or yield tensile stress (strength) for the piston material (Pa). 2.2.1.2 The number of piston rings From Figure 2, we have total number of rings = 4 (number of compression rings = 3 and number of oil ring = 1) 2.2.1.3 Design of the radial thickness of the piston ring, t1 Consider Eq. (2) for the design of piston ring radial thickness. 𝑡1 = 𝐷√ 3𝑝𝑤 𝜎𝑝 (2) where 𝑝𝑤 is an allowable radial pressure of the gas on the cylinder wall taken as 0.025 Mpa, σp is permissible bending or tensile stress for cast iron rings which is 84 Mpa. 2.2.1.4 Design of the axial thickness of piston ring, t2 Also, consider Eq. (3) for the design of piston ring axial thickness. 𝑡2 = 𝐷 10𝑛𝑅 or = 0.7t1 (3) where nR = number of rings taken as 4. 2.2.1.5 Determining the length of the piston pin in the connecting rod bushing, 𝒍𝟏 Eq. (4) gives the length of the piston pin. 𝑙1 = 0.45𝐷 (4) 2.2.1.6 Design of the width of the piston top land h1 h1= 1.2 tC (5) 2.2.1.7 Design of the width of other piston ring lands h2 h2 = 0.75t2 (6) Journal of Mechanical Engineering and Technology (JMET) 30 ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 2.2.1.8 Determining the piston barrel Piston Barrel thickness t3 at the top end is; t3 = 0.03D + b1 + 4.5 (7) b1 = t1 + 0.4 (8) where b1 = radial depth of the piston ring groove (mm). The piston barrel thickness t4 at the open end is: t4 = 0.25 t3 (9) 2.2.1.9 Design of the length of the piston and piston skirt Length of the piston skirt, ls = 0.6 D (10) Total Length of Piston L = Length of the piston skirt + Length of the ring section + Top land = ls + (4 t2 + 3 h2) + h1 (11) The length of the piston usually varies from D and 1.5D. 2.2.1.10 Design of the diameter of the piston boss and pin Outside diameter d0 of piston pin: 𝑑0 = 0.3𝐷 (12) Piston Boss diameter d = 1.5 d0 (13) Although, d0 is given in the owner’s manual. The value is 36 mm. The inside diameter d1 of the piston pin: d1 = 0.6 d0 (14) 2.2.1.11 Design of the centre of the pin The centre of the pin is 0.02D to 0.04D above the centre of the skirt. Centre of pin = 0.04D + 0.5 ls (15) The specifications for designing and modelling the conventional piston of the diesel- engine with the help of SolidWorks software were that of the ZS1115NM single- cylinder, inline and four-stroke direct injection diesel engine manufactured by Changchai Company Ltd, China. The engine specifications are given in Table 1 [24]. Equations (1) through (15) can only be used in designing the piston if the maximum gas pressure 𝑝𝑚𝑎𝑥 is known. The maximum gas pressure from our PhD work was 10.2 x 10 6 N/m2 or 10.2 N/mm2 [22]. The yield tensile strength of the material used for the piston, 3D Modelling of a Reconditioned Piston of a Single- Cylinder Four-Stroke Diesel Engine by Using Solid Works Software ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 31 t  = 372 N/mm2 [22]. Table 2 summarizes the sizes obtained from the design of the piston elements. Table 1: Engine specification Item Specification Engine model ZS1115NM Type Single cylinder, four stroke, horizontal type, direct injection Cylinder bore (D) (mm) 115 Piston stroke (𝐿𝑆) (mm) 115 Piston displacement (Vs) (litre) 1.19 Compression ratio (c.r) 17:1 Rated output/brake power (b.p)(kW) 15.7 Rated speed (N)(Rev/min) 2200 Brake specific fuel consumption (bsfc) (g/kWh) ≤ 244.8 Specific lube oil consumption (g/kWh) ≤ 2.04 Lubricating method Single circuit Cooling method Water cooled, evaporative Cooling system Radiator, natural convection Starting method Electric starting or hand cranking Fuel injection pressure (MPa) 18.13 ± 0.49 Net weight (kg) 205 Overall dimension (L x W x H) (mm) 965 x 457 x 713 Mean piston speed (cm) (m/s) 8.433 Fuel injection timing before TDC 220 Fuel type Diesel Chemical formula C14.4H24.9 Connecting rod length (𝐿𝑅 ) (mm) 258.5 Intake valve closes after TDC 380 Table 2: Size of piston parameters S/N Piston element Size obtained (mm) 1 Cylinder bore, 𝐷 115 2 Thickness of the piston head, 𝑡𝐶 8.25 3 Radial thickness of the piston ring, 𝑡1 3.436 4 Axial thickness of the piston ring, 𝑡2 2.405 5 No of the piston rings, 𝑛𝑅 4 6 Width of the top land, ℎ1 9.9 7 Width of the ring land, ℎ2 1.80375 8 Radial depth of the piston ring groove, 𝑏1 3.836 9 Thickness of the piston barrel at the top end, 𝑡3 11.786 10 Thickness of the piston barrel at the open end, 𝑡4 2.9465 11 Piston pin diameter, 𝑑0 34.5 12 Diameter of the piston boss, 𝑑 51.75 13 Length of Skirt, 𝑙𝑠 69 14 Total length of the piston, 𝐿 93.93 15 Centre of pin above the centre of the skirt 39.10 16 Inside diameter of the piston pin, 𝑑1 20.7 17 Length of the piston pin in the connecting rod bushing, 𝑙1 51.75 Journal of Mechanical Engineering and Technology (JMET) 32 ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 2.3 SolidWorks modelling of the conventional piston The sizes obtained from the design of the piston elements in Table 4 were used in modelling the conventional piston in SolidWorks CAD Software [23,25]. Figures 5 and 6 show the views of the modelled conventional piston. Figure 5: The isometric view of the 3D modelled conventional piston Figure 6: The sectional view of the modelled conventional piston 3D Modelling of a Reconditioned Piston of a Single- Cylinder Four-Stroke Diesel Engine by Using Solid Works Software ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 33 2.4 SolidWorks modelling of the bond-coat layer The bond-coat layer of 0.15 mm thick was modelled in SolidWorks software. See Figure 7. Figure 7: The modelled isometric view of the bond-coat layer of 0.15 thickness 2.5 SolidWorks modelling of the topcoat layer The topcoat layer of 0.35 mm thick was modelled in SolidWorks software. See Figure 8. Figure 8: The modelled isometric view of the topcoat layer of 0.35 thickness Journal of Mechanical Engineering and Technology (JMET) 34 ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 2.6 SolidWorks assembling of the conventional piston, bond and topcoats layers The assembling of the piston, bond-coat and topcoat layers was also carried out using the SolidWorks software. Figures 9 and 10 show the views of the modelled reconditioned piston. Figure 9: The assembly view of the reconditioned piston with bond and topcoat layers Figure 10: The exploded view of the reconditioned piston with bond and topcoat layers 3D Modelling of a Reconditioned Piston of a Single- Cylinder Four-Stroke Diesel Engine by Using Solid Works Software ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 35 3.0 RESULTS AND DISCUSSION Figures 6 to 11 show the results of modelling conventional and reconditioned pistons of the ZS1115NM single-cylinder, inline and four-stroke direct injection diesel engine using SolidWorks 2013 CAD. This modelling provides the next stage involved in the reconditioning or coating of diesel engine pistons for improved performance. Findings from literature have it that reconditioned or thermal barrier coated pistons with a ceramic material that have a very low thermal conductivity give higher piston surface temperature and brake thermal efficiency, reduced brake specific fuel consumption and emissions than the conventional ones. 4.0 CONCLUSIONS Due to the upsurge of counterfeit spare parts in the market, meeting the original equipment manufacturer (OEM) standards requires a reconditioning process. Having modelled the thermal barrier-coated piston of a single-cylinder, inline and four-stroke direct injection diesel engine using SolidWorks 2013 CAD, it could be concluded that with given engine specification suitable materials for designing and modelling a reconditioned piston of diesel engine are chosen and the model reconditioned. ACKNOWLEDGEMENTS We appreciate God almighty and families for supporting us during this work. REFERENCES [1] B. Ekrem, “Thermal analysis of functionally graded coating AlSi alloy and steel pistons”, Journal of Energy Conversion and Management, vol. 202, no. 16, pp. 325-336, 2008. [2] J.I. Ramos, Internal Combustion Engine Modelling, 2nd Edition. USA: Taylor and Francis, 1989. [3] J.B. Heywood, Internal Combustion Engine Fundamentals, International Edition. USA: McGraw-Hill Book Company, 1988. [4] J.A. Dolan, Motor Vehicle Technology and Practical Work, Reprinted edition. Ibadan: Heinemann Educational Books Ltd, 1991. [5] M.D. Röhrle, Pistons for Internal Combustion Engines – Fundamentals of Piston Technology, 2nd Edition. Germany: Verlag ModerneIndustrie, 1995. [6] G.S. Shirisha and D.K. Sravani, “Thermal analysis of IC engine piston using finite element method”, International Journal of Mechanical Engineering and Computer Applications, vol. 4, no. 1, pp. 200-209, 2016. [7] S. Lokesh, S.R. Suneer, H. Taufeeque and K. Upendra, “Finite element analysis of piston in ANSYS”, International Journal of Modern Trends in Engineering and Research (IJMTER), vol. 2, no. 4, pp. 619-626, 2015. Journal of Mechanical Engineering and Technology (JMET) 36 ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 [8] J.R. Davis, Handbook of Thermal Spray Technology. USA: ASM International, 2004. [9] T. Anders, Thermal Barrier-Coatings for Diesel Engines, 1st Edition. Sweden: KTH Royal Institute of Technology, 2017. [10] P.M. Pierz, “Thermal Barrier-Coating Development for Diesel Engine Aluminium Pistons”, Surface and Coatings Technology, vol. 61, no. 1, pp. 60-66, 1993. [11] A. Rohini and S. Prema, “A review on thermal barrier-coating for diesel engine and its characteristics studies”, International Conference on Thermo-fluids and Energy Systems, vol. 1473, pp. 1-11, 2020. [12] F.A. Ansari and Y. Dhanajay, “Review paper on simulation, analysis and validation on thermal barrier coated piston of diesel engine”, International Research Journal of Modernization in Engineering Technology and Science, vol. 4, no. 2, pp. 260-270, 2022. [13] P. Adnan, Y. Halit, H. Can and K. Ahmet, “The effects of injection timing on NOx emissions of a low heat rejection indirect diesel injection engine”, Journal of Applied Thermal Engineering, vol. 25, pp. 3042–3052, 2005. [14] B. Ekrem, E. Tahsin and C. Muhammet, “Effects of thermal barrier-coating on gas emissions and performance of a LHR engine with different injection timings and valve adjustments”, Journal of Energy Conversion and Management, vol. 47, pp. 298–1310, 2006. [15] B. Ekrem and C. Muhammet, “Thermal Analysis of a Ceramic Coating Diesel Engine Piston Using 3-D Finite Element Method”, Journal of Surface and Coatings Technology, vol. 202, pp. 398–402, 2007. [16] R. Navin, A.K. Mohammad, V. Mahendra and H.T. Yew, “Effect of thermal barrier- coating on the performance and emissions of diesel engine operated with conventional diesel and palm oil biodiesel”, Coatings, vol. 11, no. 692, pp. 1-14, 2021. [17] K. Masera and A.K. Hossain, “Combustion characteristics of cottonseed biodiesel and chicken fat biodiesel mixture in a multi-cylinder compression ignition engine”, SAE Tech vol. 4, pp. 1-14, 2019. [18] K.A. Khor, Y. Murakosh, M. Takahashi, and T. Sano, “Plasma spraying of titanium aluminide coatings: process parameters and microstructure”, Journal of Materials Processing Technology, vol. 48, pp. 413–419, 1995. [19] F.O. Isaac, “A Review of coating methods and their applications in compression and spark-ignition engines for enhanced performance”, FUOYE Journal of Engineering and Technology, vol. 7, no. 2, pp. 217-221, 2022. [20] S. Malmberg and J. Heberlein, “Effect of plasma spray operating conditions on plasma jet characteristics and coating properties”, Journal of Thermal Spray Technology, vol. 2, no. 4, pp. 339–344, 1993. [21] S. Kuldeep and O.P. Jakhar, “The behaviour of temperature on insulated (MgZrO3) diesel engine piston with ANSYS”, International Journal of Emerging Technology and Advanced Engineering, vol. 4, no. 8, pp. 692-695, 2014. 3D Modelling of a Reconditioned Piston of a Single- Cylinder Four-Stroke Diesel Engine by Using Solid Works Software ISSN 2180-1053 e-ISSN 2289-8123 Vol.15 No.1 37 [22] F.O. Isaac, “Investigation of the effectiveness of thermal barrier coating in reconditioning diesel engine piston crown,” Ph.D. Dissertation, Department of Mechanical Engineering, Ambrose Alli University, Ekpoma, Edo State, 2023. [23] F.O. Isaac and L. Abu, (2022). “Modelling of a conventional piston of a single-cylinder four-stroke diesel engine by using SolidWorks”, FUOYE Journal of Engineering and Technology, vol. 7, no. 1. pp. 65-68, 2022. [24] ZS1115NM, Single Cylinder Diesel Engine Owner’s Manual. Changchai Company Ltd, China, 2015. [25] B.D. James, Engineering Design and Graphics with SOLIDWORKS, 1st edition. Boston: Pearson, 2016.