New Design and Analysis of Diesel Exhaust Manifold to Control Thermal Gradient

Optimization and design of new configurations in the field of engineering became faster and more accurate by improving three dimension modeling software and computational fluid dynamics methods. Exhaust manifold of the marine diesel engine, which transfers hot gases from cylinders to the turbocharger, has a problem with extreme thermal gradients and crack creation which cause coolant leakage to the combustion gases paths. Thus, the turbocharger and engine operation will be interrupted. In cooling systems, the main goal is to achieve uniform thermal distribution. In order to improve the heat transfer and prevent crack occurrence at the detected critical points, new configurations in geometrics design for exhaust manifold were studied in this paper. Two Proposed configurations were designed in the Solidworks modeling software. Flow simulation of thermal analysis was performed in ANSYS CFX by using Rensselaer Polytechnic Institute wall boiling model for subcooled boiling at the low pressure. Analysis indicated the single channel configuration, performed by removing output-separating wall on hot gases side, provide more uniform temperature distribution in the manifold body Results showed the correct operation of new manifold geometry that reduces the maximum temperature of the body up to 27.36% and controls the extreme (amount of) thermal gradients and risk of crack occurrence.