CFD Analysis and Experimental Investigation of a Heavy Duty D.I. Diesel Engine Exhaust System

Abstract

Exhaust manifold is one of the most critical components of an internal combustion engines and overall engine performance can be obtained from the proper optimized design of engine inlet and exhaust systems. In this study two exhaust system models with different configuration (the existing as base one and the modified one) are simulated using ANSYS-CFX 15 with the appropriate boundary conditions and fluid properties specified to the system with suitable assumptions. The model is based on solving NAVIERE STOKES and energy equations in conjunction with the standard K-ε turbulence model. The first design is a single pipe receives exhaust gases from all runners and delivers the exhaust gases to turbocharger inlet. But the second design consists of two tubes each of one receives the exhaust gases coming from the three cylinders only. This design makes the intensity of the exhaust pulses of high pressure, which leads to increase the speed of the turbocharger. The uniformity of the flow field and back pressure variations in the two models are discussed in. A decrease in backpressure and increase in velocities are shown using the pressure contour and the velocity contour in the exhaust manifold as well as temperature distribution inside the exhaust manifold system. The best design is also simulated at different engine speed. Finally the modified model with limited back pressure was fabricated and experiments are carried out on a fully instrumented six cylinder in line water cooled heavy duty direct injection diesel engine; (350 hp@2200 rpm and 1400 Nm@1350 rpm).The pressure and temperature are measured at definite points in the exhaust gas manifold. The results obtained by experimental work were compared with the analytic CFD and found to be closely matching with accepted error.

Enhancing the Durability of Connecting Rod of a Heavy-Duty Diesel Engine

“…The engine main characteristics are experimentally measured at different speeds and loads, especially at the conditions of the maximum torque and power output with and without increasing the boost pressure (basic and upgraded engine) [18][19][20][21]. The main features of the engine and the connecting rod are listed in Table 1.…”

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

“…Parts of the exhaust system, such as valves, manifolds, and also the firing order are the main determinants of the exhaust flow dynamics. Emara et al [14] examined the flow in the manifold by opening the exhaust valves of a six-cylinder diesel engine as couples. A new manifold was designed via examining the pressure drop and the uniformity of the flow structure.…”