One-Dimensional Gas Flow Analysis of the Intake and Exhaust System of a Single Cylinder Diesel Engine

Abstract

In order to design a diesel engine system and to predict its performance, it is necessary to analyze the gas flow of the intake and exhaust system. Gas flow analysis in a three-dimensional (3D) format needs a high-resolution workstation and an enormous amount of time for analysis. Calculation using the method of characteristics (MOC), which is a gas flow analysis in a one-dimensional (1D) format, has a fast calculation time and can be analyzed with a low-resolution workstation. However, there is a problem with poor accuracy in certain areas. It was assumed that the reason was that 1D could not implement the shape. The error that occurs in the shape of the bent pipe used in the intake and exhaust ports of the diesel engine was analyzed and to find a solution to the low accuracy, the results of the experiment and 1D analysis were compared. The discharge coefficient was calculated using the average mass flow rate, and as a result of applying it, the accuracy was improved for the maximum negative pressure by 0.56–1.93% and the maximum pressure by 3.11–7.86% among the intake pipe pressure results. The difference in phase of the exhaust pipe pressure did not improve. It is considered as a limitation of 1D analysis that does not improve even by applying the discharge coefficient. In the future, we intend to implement a bent pipe that cannot be realized in 1D using a 3D format and to prepare a method to supplement the reliability by using 1D–3D coupling.

1D–3D Coupling Algorithm of Gas Flow for the Valve System in a Compression Ignition Engine

“…Benson et al applied the MOC to the boundary condition of a diesel engine by calculating the pressure wave using Riemann variables called characteristics [22]. It has been verified for accuracy and is used for gas flow analysis of diesel engines [23]. The characteristics can be calculated using a non-dimensional physical quantity and are expressed as λ or β depending on the direction of the pressure wave.…”

A 1D–3D Approach for Fast Numerical Analysis of the Flow Characteristics of a Diesel Engine Exhaust Gas

“…In the author's previous study, a method of applying a discharge coefficient was used to increase the accuracy of the results of a 1D gas flow analysis. The method of applying the discharge coefficient can improve the pressure error, but there was a limit, and the phase difference caused by the complex shape cannot be improved [14]. In addition, 1D gas flow analysis is not suitable for analyzing gas flow according to shape changes, since analysis results such as pressure and velocity cannot be expressed in contours.…”

Marine Engines Performance and Emissions II

“…According to this, the Special Issue, "Marine Engines Performance and Engines", published as a book [1], was prepared to collect works relating to marine engine performance and emissions in general. A total of 12 works [2][3][4][5][6][7][8][9][10][11][12][13] were published in this first Special Issue. In order to continue this work, the present Special Issue, "Marine Engines Performance and Engines II", was developed to include more works related to this topic, such as emissions from marine engines, after-treatments, conventional and alternative fuels, mathematical models, marine engine technology, combustion, design, control, injection, lubrication and lubes, auxiliary systems, transport, etc.…”