Accession Number:

ADA605315

Title:

Lagrangian Modeling of Evaporating Sprays at Diesel Engine Conditions: Effects of Multi-Hole Injector Nozzles With JP-8 Surrogates

Descriptive Note:

Reprint rept. Jan-Mar 2014

Corporate Author:

ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD VEHICLE TECHNOLOGY DIRECTORATE

Report Date:

2014-05-01

Pagination or Media Count:

22.0

Abstract:

Numerical modeling of the evaporation process in sprays under diesel conditions is key for the development of efficient injection strategies and to increase combustion efficiency. In this study, three-dimensional numerical simulations of single and two-hole injector nozzles under diesel conditions are conducted to study the spray behavior and the effect of multi-hole nozzles on heavy fueled spray parameters and mixing. The configuration corresponds to a high-pressure JP-8 spray injected into a high temperature pressure vessel HTPV flow-through combustion chamber simulating realistic conditions found in diesel engines. A Lagrangian particle tracking method coupled with a classical blob injection wave-based model is adopted through the use of CONVERGE solver to treat the spray process. An Adaptive Mesh Refinement AMR and fixed embedding technique is employed to capture the gas-liquid interface with high fidelity while keeping the cell-count reasonable. Two JP-8 liquid fuel surrogates, Surrogate-C of 60 n-dodecane, 20 methylcyclohexane, 20 o-xylene, and the Modified Aachen surrogate 80 n-dodecane and 20 trimethylbenze were interrogated resulting in good agreement with high fidelity spray measurements. Spray simulation results are compared to our in-house experimental data for JP-8 with single axial hole and two-hole adjacent 60 nozzle configurations. Standardized Engine Combustion Network ECN Spray A ambient conditions, consisting of 900 K and 60 bar, are selected with a rail pressure of 1000 bar with nominal nozzle diameter 147 . Utilizing Reynolds-Average Navier Stokes, and dynamic structure Large Eddy Simulation methodologies both configurations result in a 20 mm mean liquid length for both single and two hole cases. This is in good agreement with experiments with the single, while for the double hole this is an over-prediction of 3-5 mm. The reported differences are partially attributed to the internal nozzle flow dynamics, reported

Subject Categories:

  • Numerical Mathematics
  • Jet and Gas Turbine Engines

Distribution Statement:

APPROVED FOR PUBLIC RELEASE