Potential of Porous-Media Combustion Technology as Applied to Internal Combustion Engines

Abstract

The paper summarizes the knowledge concerning porous media combustion techniques as applied in engines. One of most important reasons of this review is to introduce this still not well known technology to researchers doing with internal combustion engine processes, thermal engines, reactor thermodynamics, combustion, and material science. The paper gives an overview of possible applications of a highly porous open cell structures to in-cylinder processes. This application means utilization of unique features of porous media for supporting engine processes, especially fuel distribution in space, vaporization, mixing with air, heat recuperation, ignition and combustion. There are three ways for applying porous medium technology to engines: support of individual processes, support of homogeneous combustion process (catalytic and non-catalytic) with temperature control, and utilization of the porous structure as a heat capacitor only. In the first type of application, the porous structure may be utilized for fuel vaporization and improved fuel distribution in space making the mixture more homogeneous in the combustion chamber. Extension of these processes to mixture formation and ignition inside a combustion reactor allows the realization of a homogeneous and a nearly zero emissions level combustion characterized by a homogeneous temperature field at reduced temperature level.

Drop Impact onto a Metallic Porous Layer: Effect of Liquid Viscosity and Air Entrapment

“…Porous surfaces find an application even in internal combustion engines. In fact, by using a layer with a specific porosity in cylinder-process, it is possible to obtain homogeneous and low emission combustion by enhancing fuel vaporization and distribution in space [4]. Another application is given by the deposition of dyes on papers in the ink-jet printing process [5].…”

Influence of Exhaust Gas Recirculation, and Injection Timing on the Combustion, Performance and Emission Characteristics of a Cylinder Head Porous Medium Engine

“…Numerous research works have been performed on the influence of in-cylinder mixture formation and combustion process on the outcome of exhaust emissions from an internal combustion engine [1][2][3]. It is well proven that homogeneous mixture results in lower particulate emission from diesel engines [4][5][6]. Researchers are trying various technologies to accomplish homogeneous mixture formation, combustion, and subsequently lower particulate emission.…”

“…Researchers are trying various technologies to accomplish homogeneous mixture formation, combustion, and subsequently lower particulate emission. One such technique to realize lower particulate emission from diesel engines is porous medium combustion [4,5]. Low nitrogen oxide emission will be the supplementary benefit of porous medium combustion technique [7,8].…”

Characteristics of Flameless Combustion in 3D Highly Porous Reactors under Diesel Injection Conditions

“…This is also clear to the authors that it is still impossible to quantify the process data in detail with porous reactor structure, its porosity, heat capacity, specific surface area, and so forth. Along the direct fuel injection into reactor volume, spray interaction with structure wall junctions and heat transfer from the reactor to fuel for its vaporization are very complex and very sensitive to any changes in reactor parameters and remain still not well recognized or understood [13].…”