NOx Emission Prediction for DI Diesel Engine: Numerical Modelling

Abstract

Strict emission norms, fewer complex emissions prediction models forces to develop a numerical model which actively control both combustion phase as well as after-treatment systems. This study is focused on the simulation and experimental investigation of simplified model for prediction of NO x emissions along with unburned zone, burned zone, adiabatic flame temperatures and species concentration especially atomic oxygen [O], Nitrogen [N 2 ] and nitric oxide [NO]. Burned flame temperature and thermal NO concentrations were simulated by enthalpy balance and Zeldovich mechanism respectively. The simulated results were validated with experimental result of Turbocharged direct injected Diesel engine at steady-state operating conditions. The maximum temperature (T max ) simulated within burned zone at 2200 rpm and 100% load is 2917 K while at 75% load, and 50% load it reduces to 2853 K, and 2776 K respectively. It was also observed that the equilibrium concentrations of [O], [NO] and [N 2 ] were directly proportional to burned zone temperature. The accuracy of proposed model was tested at 2200 rpm rated speed and also at 1400 rpm with full load, 75% load, and 50% load. NOx reduces with speed for identical operating conditions.

A Simulation Study on a Premixed-charge Compression Ignition Mode-based Engine Using a Blend of Biodiesel/Diesel Fuel under a Split Injection Strategy

“…The Fenimore mechanism, on the other hand, is only often seen under fuel-rich circumstances, which are characterized by the presence of a sufficient quantity of HC components that can react with nitrogen in the engine cylinder [67]. Therefore, it is assumed that the Zeldovich mechanism is the primary contributor to the generation of NOx in the majority of combustion circumstances [68]. Under the situation, typically, the air residue coefficient is roughly 1; the primary processes that take place in the Zeldovich mechanism are concerned with the formation and decomposition of NO [69].…”