Two-Phase Numerical Modelling of a Wet Exhaust System in a Catamaran Motor Yacht Diesel Engine

Abstract

Two-Phase Numerical Modelling of a Wet Exhaust System in a Catamaran Motor Yacht Diesel Engine Alihan Cambaz*1, Yasin Furkan Gorgulu2, Halit Arat3 *1 SU Ar-Ge Dizayn ve Mühendislik A.Ş, 77000, Yalova-Turkey, (ORCID: 0000-0001-6632-978X), cambazalihan7@gmail.com 2 Mechatronics Engineering Department, Istanbul Health & Technology University Engineering and Natural Sciences Faculty, 34025, Istanbul-Turkey, (ORCID: 0000- 0002-1828-2849), furkan.gorgulu@istun.edu.tr 3 Mechanical Engineering Department, Kutahya Dumlupinar University Engineering Faculty, 43270, Kutahya-Turkey, (ORCID: 0000-0002-6634-2535), halit.arat@dpu.edu.tr (First received 8 October 2021 and in final form 10 December 2021) (DOI: 10.31590/ejosat.1007351) ATIF/REFERENCE: Cambaz, A., Gorgulu, Y. F. & Arat, H. (2021). Two-Phase Numerical Modelling of a Wet Exhaust System in a Catamaran Motor Yacht Diesel Engine. European Journal of Science and Technology, (31), 165-170. Abstract In this study, multiphase temperature distributions and volume fractions through a wet exhaust system were investigated as 3D by using a comprehensive numerical model in a yacht diesel engine. For this purpose, the Volume of Fluid multiphase model was selected as the numerical model. Fuel exhausts are generally located underwater to ensure a modern yacht appearance and minimize exhaust noise. A scoop is positioned above the catamaran yacht exhaust to control water pressure, exhaust gases, and cooling water flow distribution. Besides, two types of fluids have been used, one of which is the hot exhaust gas the other is the cooling water used in the nozzle. The design has been created using Ansys SpaceClaim, and the cooling water is sprayed from the 60° tip of the nozzle. Moreover, the mesh used in the simulation has 1,405,113 elements, 523,125 nodes, and the average mesh skewness is 0.46, the average orthogonal quality of the mesh is 0.64. The Realizable k-ε turbulence model has been used in the simulations. According to the results, the flow fully develops after 1.5 seconds, and the water nozzle sprays the water along the tube cools the exhaust gases. Also, the stagnation points occurring at the elbow fitting of the tube are striking when the velocity contours and velocity vectors are examined.