Analysis of combustion and pollutants formation in a direct injection diesel engine using a multi-zone model

Abstract

A two‐dimensional multi‐zone model for the calculation of the closed cycle of a direct injection (DI) diesel engine is presented. The fuel spray is divided into small packages and the effect of air velocity pattern on spray development is taken into account. The calculation of swirl intensity variations during the cycle is based on hybrid solid body‐boundary layer rotation scheme. Application of the mass, energy and state equations in each zone yields local temperatures and cylinder pressure histories. For calculating the concentration of constituents in the exhaust gases, a chemical equilibrium scheme is adopted for the C‐H‐O system of the eleven species considered, together with chemical rate equations for the calculation of nitric oxide (NO). A model for the evaluation of soot formation and oxidation rates is incorporated. A comparison is made between the theoretical results from the computer program implementing the analysis, with experimental results from a vast experimental investigation conducted on a direct injection, Lister‐Petter diesel engine, with very encouraging results. Plots of temperature, equivalence ratio, NO and soot distributions inside the combustion chamber are presented, elucidating the physical mechanisms governing combustion and pollutants formation.

Measurements and analysis of load and speed effects on the instantaneous wall heat fluxes in a direct injection air-cooled diesel engine

“…At the same time, new demands are added in today's diesel engine design mainly towards the areas of controlled ignition of new fuels, the reduction of tailpipe emissions (Rakopoulos et al, 1995b) and the application of ceramic materials in the combustion chamber surfaces of low heat rejection (LHR) engines (Kamo and Bryzik, 1984;Assanis, 1989;Kouremenos et al, 1992), all of which are directly related to the details of the transient cycle heat transfer. The development of low heat rejection (or &adiabatic') diesel engines requires proper selection or development of new materials, a fact which is highly facilitated by their extensive heat transfer study (French, 1984).…”

Numerical Investigation and Multi-Objective Optimization of Internal EGR and Post-Injection Strategies on the Combustion, Emission and Performance of a Single Cylinder, Heavy-Duty Diesel Engine

“…Here SoI and α post refers to the start of main injection and post injection dwell time between the end of the main injection and the start of the post injection respectively while the PFQ (Post Fuel Quantity) denotes the post injected fuel quantity as a percentage of the total fuel mass injected. In the present work, a predictive, phenomenological (based on zone modeling) [25] DIPulse combustion model which can be used for single and multiple injection events in direct injection diesel engines [26] was employed. NO, which is the major component of engine out NO x , was estimated by three step extended Zeldovich mechanism [27].…”

Thermodynamic modeling and validation of in‐cylinder flow in diesel engines

“…The fuel spray was divided into small packages and the effect of air velocity pattern on spray development is taken into account. Engine performance could be predicted accurately by the multi zone model . Lamaris et al .…”

“…A two-dimensional multi-zone model for the calculation of the closed cycle of a direct injection diesel engine is presented by Rakopoulos et al The fuel spray was divided into small packages and the effect of air velocity pattern on spray development is taken into account. Engine performance could be predicted accurately by the multi zone model [29]. Lamaris et al developed and validated a multi zone combustion model for predicting performance characteristics and NOx emissions in large-scale two-stroke diesel engines.…”