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Title: Mixing models for the two-way-coupling of CFD codes and zero-dimensional multi-zone codes to model HCCI combustion

Journal Article · · Combustion and Flame
 [1]; ;  [2]
  1. HFV6 Performance and Emissions, GM Powertrain, MC: 480-712-140, 30003 Van Dyke Ave, Warren, MI 48090 (United States)
  2. Institut fuer Technische Verbrennung, RWTH Aachen University, Templergraben 64, 52056 Aachen (Germany)

The objective of this work is the development of a consistent mixing model for the two-way-coupling of a CFD code and a multi-zone code based on multiple zero-dimensional reactors. The two-way-coupling allows for a computationally efficient modeling of HCCI combustion. The physical domain in the CFD code is subdivided into multiple zones based on three phase variables (fuel mixture fraction, dilution, and total enthalpy). Those phase variables are sufficient for the description of the thermodynamic state of each zone, assuming that each zone is at the same pressure. Each zone in the CFD code is represented by a corresponding zone in the zero-dimensional code. The zero-dimensional code solves the chemistry for each zone, and the heat release is fed back into the CFD code. The difficulty in facing this kind of methodology is to keep the thermodynamic state of each zone consistent between the CFD code and the zero-dimensional code after the initialization of the zones in the multi-zone code has taken place. The thermodynamic state of each zone (and thereby the phase variables) will change in time due to mixing and source terms (e.g., vaporization of fuel, wall heat transfer). The focus of this work lies on a consistent description of the mixing between the zones in phase space in the zero-dimensional code, based on the solution of the CFD code. Two mixing models with different degrees of accuracy, complexity, and numerical effort are described. The most elaborate mixing model (and an appropriate treatment of the source terms) keeps the thermodynamic state of the zones in the CFD code and the zero-dimensional code identical. The models are applied to a test case of HCCI combustion in an engine. (author)

OSTI ID:
21116121
Journal Information:
Combustion and Flame, Vol. 155, Issue 3; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
Country of Publication:
United States
Language:
English