Numerical Modelling of Fouling Process in EGR System: A Review

Abstract

In order to combat climate change, the new rigorous standards for pollutant reduction have shone a light on the use of exhaust gas recirculation system in order to minimize the NOx emissions of vehicles. For this reason, the fouling problem that appears on the exhaust gas recirculation line, caused by the deposition of soot particles and hydrocarbons that are part of the exhaust gas, has become particularly relevant in the last few years. In this field, researches have proposed numerical models in order to estimate and predict the deposit formation and growth. Using various numerical techniques, they intend to determine and reproduce the fouling layer buildup considering the different mechanisms that are involved in the deposit formation. This chapter provides a detailed and comprehensive account of the numerical approaches that have been proposed to analyze the fouling phenomenon that occurs inside the exhaust gas system. The main characteristics of each numerical model, as well as their main strengths and weaknesses, are exposed and evaluated, and their simulation capabilities are examined in detail.

Experimental evaluation of the effect of ozone treatment on the oxidation and removal of dry soot deposits of the exhaust gas recirculation system

“…The three-dimensional (3D) topography of the fouling samples was captured using the optical surface profiler PLu Neox Sensofar (spatial resolution of 0.01 nm, linearity of 0.03%) configured in the confocal microscopy mode. Thus, following a protocol proposed in previous studies [ 41 , 42 ], a 5 × optical zoom lens was utilised to obtain the spatial coordinates of the points on the sample surface via non-contact methods, ensuring that the fouling deposit remained undamaged during the measurement process.…”

Investigation of Two-Way Fluid-Structure Interaction of Blood Flow at Different Temperature using CFD

“…In the case of a study flow, the velocity at the inlet was maintained at 0.3 meters per second throughout the experiment, and a pulsatile flow sinusoidal profile of inlet velocity throughout artery was utilized to imitate a physiological pulse (see Figure 2 for an illustration of this). In order to implement the suggested inlet velocity model, a user-defined function, or UDF, was penned [9][10][11]. In the ANSYS software, further information about boundary conditions will be presented.…”

Effect of soot particle deposition on porous fouling formation and thermal characteristics of an exhaust gas recirculation cooler

“…The second approach, on other hand, recreates the fouling growth using the dynamic mesh, where the position of the nodes on the fluid-fouling interface is updated at each time. It should be emphasized that in the second approach the growing fouling layer is also considered to be a solid medium [18]. Paz et al [19] employed the first approach to study the evolution of solid fouling layer thickness in an EGR cooler with reasonable agreement obtained compared to available experimental data.…”