ABSTRACT Stringent NOx and particulate emission constraints require high levels of exhaust gas recirculation. In this paper we model and analyze a Variable Valve Timing methodology that in steady-state achieves large levels of internal Exhaust Gas Recirculation (iEGR) or residual charge in Compression Ignition Direct Injection (CIDI) engines. Current external Exhaust Gas Recirculation (eEGR) te...

A mathematical model for the prediction of internal recirculation of complex impinging stream reactors has been presented. The model constitutes a repetition of a series of ideal plug flow reactors and CSTR reactors with recirculation. The simplicity of the repeating motif allows for the derivation of an algebraic relation of the whole system using the Laplace transform. An impinging stream...

Volumetric combustion has been developed to realize a high substitution ratio of biomass in co-firing boilers, which features an intensive flue gas internal recirculation inside furnace. However, the characteristics of NOx and SOx emissions in large-scale boilers with volumetric combustion were not fully clear. In this paper, an Aspen Plus model of volumetric combustion system was built up base...

A two-layer quasigeostrophic model is used to investigate the influence of stratification on the inertial recirculation in a full basin model. It is found that the barotropic transport of the inertial recirculation is intensified significantly through barotropic–baroclinic interactions in the presence of a shallow thermocline or a strong stratification. Weakly nonlinear theories and numerical e...

Recirculation during dual lumen veno-venous (DLVV) extracorporeal membrane oxygenation (ECMO) is a dynamic event that results in a fraction of the oxygenated blood exiting the arterial lumen and immediately shunting back into the venous lumen. Excessive recirculation will result in suboptimal oxygen delivery to the patient. Ultrasound dilution is a technology that has been shown to rapidly quan...

The concepts of residual gas and admission (or volumetric efficiency) coefficients are used exclusively by specialists in the field piston Internal Combustion Engines. However, it is preferable to apply volume fractions components working mixture consisting air, fuel, residual, recirculating gases, for evaluation filling. This simplifies makes more easy-to-grasp influence individual factors on ...

INTRODUCTION The aim of this study was to determine access recirculation in functioning catheters in the regular and reversed positions. MATERIALS AND METHODS Access recirculation was measured in 2 sequential hemodialysis sessions in patients with functioning internal jugular catheters inserted not earlier than 2 weeks before the study. The arterial and venous lines were in their regular posi...

This paper presents a numerical analysis using the CFD Fluent (6.3.26 version) program to identify the effects that can be generated when using radiant tubes with internal recirculation of combustion products, but with a pre-combustion chamber. The numerical results are validated with an experimental assembly based on the outlet deviation of gases temperature. These deviations were less than 5 ...

In this paper we analyze the nonlinear dynamic be havior of an internal exhaust gas recirculation system based on the mean value model of an experimental en gine equipped with a camshaft phaser We develop a dynamic camshaft timing schedule that regulates the in ternal exhaust gas recirculation system while maintain ing transient engine torque response similar to an engine with zero exhaust gas ...

Many practical applications exploit an external local magnetic field – magnetic obstacle – as an essential part of their construction. Recently, Votyakov et al. (2007) have demonstrated that the flow of an electrically conducting fluid influenced by an external field can show several kinds of recirculation. The present paper reports a 3D numerical study whose some results are compared with an e...