Influences of the dead end on the flow characteristics at the exhaust manifold of a marine diesel engine

Abstract

A 3D Computational Fluid Dynamics (CFD) model of an exhaust manifold with and without a dead end has been developed to investigate the impacts of its geometry on the flow structure and the pressure distribution within the manifold. The model differs from previously studied models principally for its ability to approach the realistic operating principle of an engine as the modelled exhaust valves of the investigated engine open and close according to the firing order. The experimental results of an exhaust manifold without a dead end has been used to validate the CFD model through the pressure distribution and the flow structure. The outcomes demonstrated that the developed CFD model concurred well with the experimental data. The effects of the dead end on the exhaust manifold were then investigated using the validated CFD model. The study has revealed that the addition of a dead end (i) provides a smoother pressure distribution inside the manifold and increase in the efficiency of the turbocharger and (ii) decreases the pressure inside of the interconnection pipes of cylinders while the exhaust gas discharges. Moreover, the results disclose a smoother discharge of exhaust gases leading to a more effective sweeping of the exhaust gas thorough the cylinder without causing any exhaust backpressure. Furthermore, the dead end reduces the turbulence kinetic energy at the blind end of the exhaust manifold resulting in a decrease of pressure loss within. The abovementioned findings regarding to the flow structure and the pressure distribution within the exhaust manifold improve the efficiency of the engine.

Keywords

• Exhaust manifold
• Dead end
• Computational fluid dynamics
• Pressure distribution

References

1. [1] Renberg U, Ångström HE, Fuchs L. CA Comparative Study Between 1D and 3D Computational Results for Turbulent Flow in an Exhaust Manifold and in Bent Pipes. (SAE Paper No 2009-01-1112) 2009. [CrosRef]
2. [2] Zhong W, He Z, Jiang Z, Huang Y. CA flow field analysis of pulse converter exhaust manifold of diesel engines. Advanced Materials Research 2012;468-471:1693–1696. [CrosRef]
3. [3] Wang Y, Semlitsch B, Mihaescu M and Fuchs L. Flow structures and losses in the exhaust port of an internal combustion engine. International Mechanical Engineering Congress and Exposition - IMECE2013-64610 2013. [CrosRef]
4. [4] Ozsoysal OA. Analytical and Experimental Investigation of High Speed Marine Diesel Engines. Doctoral Dissertation, İstanbul Technical University, Turkey, 1991. (Turkish)
5. [5] Ozsoysal OA. Investigation of the Engine Data by Comparing the Experimental Test with the Results of Analytical Model 1993. (SAE Paper No. 930611). Paper presented at the meeting of International Congress and Exposition, Detroit, Michigan. [CrosRef]
6. [6] Luján JM, Galindo J, Serrano JR, Pla B. A methodology to identify the intake charge cylinder-to-cylinder distribution in turbocharged direct injection diesel engines. Measurement Science and Technology 2008;19:065401. [CrosRef]
7. [7] Xu J, Zhou S. Analysis of flow field for automotive exhaust system based on computational fluid dynamics. The Open Mechanical Engineering Journal 2014;8:587–593. [CrosRef]
8. [8] Nursal RS, Hashim AH, Nordin NI, Hamid MAA, Danuri MR. CFD analysis on the effects of exhaust backpressure generated by four-stroke marine diesel generator after modification of silencer and exhaust flow design. ARPN Journal of Engineering and Applied Sciences 2018;12:4.

9. [9] Ardabili SF, Najafi B, Shamshirband S, Bidgoli BM, Deo RC, Chau KW. Computational intelligence approach for modeling hydrogen production: a review. Engineering Applications of Computational Fluid Mechanics 2018;12:438–458. [CrosRef]
10. [10] Zhang J, Zhang X, Wang T, Hou X. A numerical study on jet characteristics under different supercritical conditions for engine applications. Applied Energy 2019;252:113428. [CrosRef]
11. [11] Wu S, Zhou D, Yang W, Implementation of an efficient method of moments for treatment of soot formation and oxidation processes in three-dimensional engine simulations. Applied Energy 2019;254:113661. [CrosRef]
12. [12] Zhang C, Hu B, lai C, Zhang H, Qin L, Leng X, Huang W. Simulation Study of 1D-3D Coupling for Different Exhaust Manifold Geometry on a Turbocharged Gasoline Engine (SAE Paper No 2018-01-0182) 2018. [CrosRef]
13. [13] Payri F, Reyes E, Galindo J. Analysis and modeling of the fluid-dynamic effects in branched exhaust junctions of ICE. Journal of Engineering for Gas Turbines and Power 2001;123:197–203. [CrosRef]
14. [14] Emara K, Emara A, Razek EA. CFD Analysis & Experimental Investigation of a Heavy Duty D.I. Diesel Engine Exhaust System. Paper presented at the meeting of the International Mechanical Engineering Congress and Exposition 2016, Phoenix, Arizona, USA. [CrosRef]
15. [15] Hinterberger C, Olesen M. Automatic Geometry Optimization of Exhaust Systems Based on Sensitivities Computed by a Continuous Adjoint CFD Method in OpenFOAM 2010. (SAE Paper No. 2010-01-1278). SAE International. [CrosRef]
16. [16] Siqueira C, de La R, Kessler MP, Rampazzo R, Cardoso DA. Three Dimensional Numerical Analysis of Flow Inside Exhaust Manifold 2006. (SAE Paper No. 2006-01-2623). Paper presented at the meeting of XV Congresso e Exposição Internacionais da Tecnologia da Mobilidade, São Paulo, Brasil.
17. [17] Xu P, Jiang H, Zhao X. CFD analysis of a gasoline engine exhaust pipe. Journal of Applied Mechanical Engineering 2016;5:2. [CrosRef]
18. [18] Umesh KS, Pravin VK, Rajagopal K. CFD analysis and experimental verification of effect of manifold geometry on volumetric efficiency and back pressure for multi-cylinder si engine. International Journal of Engineering & Science Research 2013;3: 342–353.
19. [19] Rajadurai S, Paulraj M, Victor A. Effective Methodology for Backpressure Prediction of Hot Exhaust Gas in Cold Flow Bench Test 2016. (SAE Paper No. 2002-01-0901). [CrosRef]
20. [20] Ma Z, Chen X, Gao D, Xu B. The CFD analysis of exhaust runner for GW15 gasoline engine. Advanced Materials Research 2013;655-657:326–331. [CrosRef]
21. [21] Pulliam TH, Zingg DW. Fundamental algorithms in computational fluid dynamics. Scientific Computation 2014:59–74. [CrosRef]
22. [22] Menter FR. Improved two-equation k-omega turbulence models for aerodynamic flows. ASA STI/Recon Technical Report N. 1992
23. [23] Lee CH. Rough boundary treatment method for the shearstresstransport k - ω model, Engineering Applications of Computational Fluid Mechanics 2018;12:261–269. [CrosRef]
24. [24] Launder BE, Spalding DB. The numerical computation of turbulent flows. Computer Methods in Applied Mechanics and Engineering 1974;3:269–289.
25. [25] Wilcox DC. Reassessment of the scale-determining equation for advanced turbulence models. AIAA Journal 1988;26:1299–1310. [CrosRef]
26. [26] Davidson L. Fluid mechanics, turbulent flow and turbulence modeling 2014. Master of Science Dissertation, Chalmers University of Technology, Sweden.