Numerical study using detailed chemistry combustion comparing effects of wall heat transfer models for compression ignition diesel engine

Abstract

The present work highlights the effect of wall heat transfer models on numerical predictions of combustion phenomenon in compression ignition diesel engine. A comparison of engine's performance is made using O'Rourke and Amsden, Han and Reitz and Angelberger heat transfer models. A detailed chemistry model employed comprises of 61 species and 235 reactions for n-heptane/diesel combustion. RANS RNG k-ε turbulence model (Reynolds-averaged Navier-Stokes: RANS; re-normalisation group: RNG; turbulent kinetic energy-rate of dissipation of turbulence energy: k-ε turbulence model) is used here to model mass, momentum and energy transport equations for engine computational fluid dynamics simulations. The study performed is on turbocharged 130PS 5.675L diesel engine and presented against experimental findings. Effect of different wall treatment models on accuracy and inherent computational time requirement for predicting engine P-θ (cylinder pressure vs. crank angle) curve, indicated mean effective pressure and AHRR (apparent heat release rate) is discussed in this paper. This comparative study facilitates in choosing optimum heat transfer model for in-cylinder combustion study vis-à-vis the trade-offs between solution accuracy (which drives product quality) versus computational time (which drives time to market).

Reduction of Diesel Engine Emissions Using Phase Change Materials

“…Figure 1 shows the methodology utilized in this work's logical order of activities. This equation uses the following constants: k is the molecular conductivity; κ is the von Karman constant (0.4187); B is the function defined by the value of u+ when y+ equals 1; Prm and Prt are the molecular and turbulent prandtl numbers; Tf and Tw are the fluid and wall temperatures; and uτ is the shear speed (derived from the wall's momentum law) [32]. (Eq.…”

Numerical Simulation on the Spray Angle of the Dual-layer Hole Nozzle in a Partition Combustion System of the Diesel Engine

“…The spray breakup utilizes the WAVE model, while collision employs the Naber Reitz oil droplet-wall collision model with a Wal1jet1 interaction type, C2=12, a critical Weber number of 50, and reflection angles less than 5°. Oil droplet evaporation relies on the Dukowicz model, ignition uses the Shell auto-ignition model, and combustion is modeled using the ECFM-3Z approach [21]. NO X emission is estimated using the Zeldovich model, and Soot emission is predicted using the Kennedy-Hiroyasu-Magnussen model [22].…”