Investigating the Effect of Utilizing New Induction Manifold Designs on the Combustion Characteristics and Emissions of a Direct Injection Diesel Engine

Abstract

New induction manifold designs have been developed in this work to enhance the turbulence intensity and improve the mixing quality inside diesel engine cylinders. These new designs employ a spiral-helical shape with three different helical diameters (1D, 2D, 3D; where D is the inner diameter of the manifold) and three port outlet angles: 0 deg, 30 deg, and 60 deg. The new manifolds have been manufactured using three-dimensional printing technique. Computational fluid dynamics simulations have been conducted to estimate the turbulent kinetic energy (TKE) and the induction swirl generated by these new designs. The combustion characteristics that include the maximum pressure raise rate (dP/dθ) and the peak pressure inside the cylinder have been measured for a direct injection (DI) diesel engine utilizing these new manifold designs. In addition, engine performance and emissions have also been evaluated and compared with those of the normal manifold of the engine. It was found that the new manifolds with 1D helical diameter produce a high TKE and a reasonably strong induction swirl, while the ones with 2D and 3D generate lower TKEs and higher induction swirls than those of 1D. Therefore, dP/dθ and peak pressure were the highest with manifolds 1D, in particular manifold m (D, 30). Moreover, this manifold has provided the lowest fuel consumption with the engine load by about 28% reduction in comparison with the normal manifold. For engine emissions, m (D, 30) manifold has generated the lowest CO, SO2, and smoke emissions compared with the normal and other new manifolds as well, while the NO emission was the highest with this manifold.

An experimental and numerical investigation of the effects of the diaphragm pressure ratio and its position on a heated shock tube performance

“…A variety of recent studies were conducted involved using shock tubes along with high‐density fuel/air mixtures to obtain combustion features of conventional and alternative fuels at conditions relevant to those used in internal combustion engines and gas turbine machines 5‐8 . Ignition delay time (IDT), particularly in internal combustion engines, is a vital combustion characteristic that directly affects engine efficiency and exhaust emissions 9‐13 . This property in ICE can be defined as the time required to detect heat release once the air–fuel mixture reaches the self‐ignition (autoignition) temperature and pressure or the time interval between the start of ignition (raising injector needle) and the beginning of combustion 14 .…”

“…[5][6][7][8] Ignition delay time (IDT), particularly in internal combustion engines, is a vital combustion characteristic that directly affects engine efficiency and exhaust emissions. [9][10][11][12][13] This property in ICE can be defined as the time required to detect heat release once the air-fuel mixture reaches the self-ignition (autoignition) temperature and pressure or the time interval between the start of ignition (raising injector needle) and the beginning of combustion. 14 The total delay period is due to a combination of physical and chemical delays.…”